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mw0uzo
05-18-2012, 11:58 AM
Been building an amp.. enjoy 1st stage of amp module construction :)

Drilling up the copper

http://s19.postimage.org/v29l89ppb/SV203113.jpg (http://postimage.org/image/v29l89ppb/)

And the transistors

http://s19.postimage.org/my1h3j3a7/SV203163.jpg (http://postimage.org/image/my1h3j3a7/)

And components

http://s19.postimage.org/ba7f8ze5b/SV203170.jpg (http://postimage.org/image/ba7f8ze5b/)

transistors ...

http://s19.postimage.org/bpnafqpgf/SV203172.jpg (http://postimage.org/image/bpnafqpgf/)

Test setup:

http://s19.postimage.org/pofeegpcv/SV203178.jpg (http://postimage.org/image/pofeegpcv/)

First 100W! (of 600w)

http://s19.postimage.org/a0e77o9r3/SV203176.jpg (http://postimage.org/image/a0e77o9r3/)

mw0uzo
05-18-2012, 11:58 AM
Brackets

http://s19.postimage.org/4hbnqgcpr/SV203187.jpg (http://postimage.org/image/4hbnqgcpr/)

Wiring

http://s19.postimage.org/wwr13r23j/SV203225.jpg (http://postimage.org/image/wwr13r23j/)

http://s19.postimage.org/j5r5fa2jj/SV203227.jpg (http://postimage.org/image/j5r5fa2jj/)

Cover

http://s19.postimage.org/s21xj7t5r/SV203228.jpg (http://postimage.org/image/s21xj7t5r/)

and laying out the insides

http://s19.postimage.org/gqz9uuman/SV203229.jpg (http://postimage.org/image/gqz9uuman/)

mw0uzo
05-18-2012, 12:02 PM
Rest of the amp will consist of custom PIC controller with 20 x 4 display (same as beacon), LPFs, foward and reverse power detection and input attenuators.

KG4CGC
05-18-2012, 12:03 PM
Nice work. I wish I had a machine/metal shop.

NQ6U
05-18-2012, 12:12 PM
How many pills is that?

mw0uzo
05-18-2012, 12:13 PM
Nice work. I wish I had a machine/metal shop.

Thanks, no machine shop here, a shed and a jigsaw to cut the steel bits, a really cheap pillar drill and a £10 tap/die set from ebay. Copper was ordered as a piece which just happened to fit perfectly.

mw0uzo
05-18-2012, 12:14 PM
How many pills is that?

How high do you want to get ;)

mw0uzo
05-18-2012, 12:15 PM
the mrf150s i have are fakes, unfortunately. But after flattening the unbelievably wonky mounting tabs, they seem to work by some stroke of sheer luck. for how long though....

KC2UGV
05-18-2012, 12:19 PM
Looks nicely done there :) Sorry you got some bunk components. Hopefully, real components wont throw anything off for you there on the final construction.

mw0uzo
05-18-2012, 12:23 PM
Looks nicely done there :) Sorry you got some bunk components. Hopefully, real components wont throw anything off for you there on the final construction.

Yeah annoying. Plan is to build all the monitoring and protection before ramping up the power. The MRF150s are 'remanufactured' (very poorly). I do not expect them to last long or work properly, but if I can get away with fakes, decent monitoring and careful abuse then that would be great :mrgreen:

kf0rt
05-18-2012, 01:22 PM
Very nice job there, OM.

Reminded me that I needed to rescue a couple of those toroidal transformers that are slated for recycling here at work (NOS). Now safely in the trunk of my car. :)

N8YX
05-18-2012, 01:23 PM
Very nice work. I'm currently walking the swap meet at the Dayton Hamvention and am running into a lot of the things necessary to build such constructs. Be nice to have some decent test gear for the design and test stages and there is no shortage of that stuff here, either.

mw0uzo
05-18-2012, 02:04 PM
The toroid is a custom wound one. I asked a transformer manufacturer to make something with minimum diameter with worse expected power requirements. My hunch is that the transformer (a 1kva 40v 20a main winding) is even now over-spec'd for what would be required. I reckon you could probably get away with a 800w 40v ac toroid for this purpose.

edit: a quick calc suggests that what i've got is a 800w continuous toroid, power draw is 1.2kw continuous at rated amp power. i asked for torioid rated at 50% duty cycle at 1.2kw, capable of maintaining a solid 50v supply. The leadouts from the transformer are *very* stout, so it should be perfect....

kf0rt
05-18-2012, 03:21 PM
Looks like a really fun project.

Pulled the datasheet on one of the two different toroids I got and it looks like it's a 1.2kva isolation transformer with two secondaries: one is 1:1 isolation and the other is center-tapped; 93/24 volts (this is spec'd at 110-120 VAC input). Guess that wouldn't be optimal for the MRF150's, but I noticed that the MRF150 is spec'd to 125 volts, so maybe they'd do okay at 93 volts instead of 50? These were used in a high-power servo motor application, and a lot of that stuff is 24/36 volts.

Just thinking aloud. ;) Odds are slim I'd ever build something like that, but it's fun to think about.

Is that a readily available PCB you're using, or something you made yourself? I'd be interested in seeing the schematic.

Hope you'll continue to show the progress here. I love seeing the craftsmanship and your talent is obvious. ;)

mw0uzo
05-18-2012, 03:41 PM
Apparently, the MOSFETs should be rated at 3x the supply voltage, so higher than 60v would probably mean BANG. The eb104 pcb I got from an ebay seller in Greece. There are two of us building these amps at the same time. We got the components and transformers from Communications Concepts in the states. They also sell the PCBs. We just added the (fake) mosfets and heatsinks.

mw0uzo
05-18-2012, 03:44 PM
Any 40v ac, high power toroid would be suitable for this. I was hoping I would find a suitable one in my line of work (audio repair) from a scrap audio amp but one didn't show, so I got a custom one.

mw0uzo
05-18-2012, 03:47 PM
The big challenge is the CPU controller and monitoring circuits really, these are in very early prototype on breadboard at the moment. Next step is to port my beacon code over to the new PIC and get the display working, then get the ADC code and SWR calculations done.

kf0rt
05-18-2012, 03:50 PM
Good to know (and learning). The last amplifier project I was involved in was based on a 4-400. Have a picture or two here somewhere, but they're black & white. (Really) Mid-1970's. Don't know a thing about the eb104, but it looks really clean.

mw0uzo
05-18-2012, 05:44 PM
Just checked out the 4-400 amplifier.. a tube amplifer. I seriously considered building a tube amplifier, but chickened out at the HV. I've repaired several 100w-200w class tube amps and a few 600w class and always am very cautious of the HV, but knowing how many times i've managed to give myself pretty bad electric shocks over the years I figured it was probably best to stick to 50v...

mw0uzo
05-18-2012, 05:50 PM
eb104 has its problems too though, in its current configuration it doesn't work efficiently above 21mhz. Those capacitors on the output transformer are the problem, they need to be reduced in value to work properly up to 10m

mw0uzo
05-18-2012, 05:56 PM
Other constructors have improved the grounding around the fets as well, but my approach is to test and fix problems as they arise rather than trying to fix everything at once. If it works good at 600w when i get there then thats good enough for me. If it goes up in smoke, expect some amusing pictures :shhh:

kf0rt
05-18-2012, 06:05 PM
5808

1974. Amp on the left is a single 4-1000 and the little guy on the right is the 4-400.

Those were the days.

mw0uzo
05-18-2012, 06:14 PM
i love the way the fronts looks so bare, but inside you know they're filled with goodness. ....and the wheels and cranks :D

kf0rt
05-18-2012, 06:44 PM
i love the way the fronts looks so bare, but inside you know they're filled with goodness. ....and the wheels and cranks :D

Roi Tan cigars and Heathkits, too.

Those were some fun times. The big amps then had variacs to adjust the power. As I recall, these adjusted the input power and could go from zero to whatever the max was. The variac was the "steering wheel" and you had to tune the amp. No broadband solid state stuff. RF deck up top and a power supply in the bottom. Plate voltage was in the kilovolts.

I once worked JY1 in a contest... Must have been 1973 or 4. Drake 4B line and a similar homebrew 4-1000 amp. Middle of the night and was just a kid.

WØGGC and WAØQLH: I still remember you guys.

KC2UGV
05-19-2012, 10:04 PM
I love seeing the craftsmanship and your talent is obvious. ;)

Yeah, he's a fucking artist when it comes to this stuff... His beacon project was/is very exciting!

mw0uzo
05-20-2012, 05:34 AM
That beacon project is sooo close to being able to make a kit out of it. I have an ongoing long term mental block on learning some PCB design software to make the boards though :/ I have http://sourceforge.net/projects/pcb/ installed and waiting for some attention. Why can i not get my arse in gear to do it?!

mw0uzo
07-31-2012, 06:36 PM
Some more progress on the EB104:

Fixing all the PSU parts
http://s15.postimage.org/otivww6c7/SV203382.jpg (http://postimage.org/image/otivww6c7/)

Wiring up
http://s15.postimage.org/qb4c8gb2v/SV203384.jpg (http://postimage.org/image/qb4c8gb2v/)

It works :)
http://s15.postimage.org/cipxctkbb/SV203391.jpg (http://postimage.org/image/cipxctkbb/)

W5GA
07-31-2012, 08:14 PM
5808

1974. Amp on the left is a single 4-1000 and the little guy on the right is the 4-400.

Those were the days.
Is that big handwheel so you can go from a kw to deathray with the flick of your wrist?

K7SGJ
07-31-2012, 08:20 PM
Is that big handwheel so you can go from a kw to deathray with the flick of your wrist?

It's a surplus hatch wheel from a German U boat.

kf0rt
08-01-2012, 07:28 AM
Is that big handwheel so you can go from a kw to deathray with the flick of your wrist?

Indeed, it is!

mw0uzo
08-01-2012, 01:08 PM
Fitted front panel switch and overload circuit breaker
http://s8.postimage.org/na785uilt/SV203396.jpg (http://postimage.org/image/na785uilt/)

And wired in the amplifier for first full 50V test ... eeek
http://s8.postimage.org/mzzpmi3zl/SV203398.jpg (http://postimage.org/image/mzzpmi3zl/)

...everything was OK though. Tried some RF and got 500W out of it for about 10w in, 1200W drawn at the socket. Was expecting more out for 10w and better efficiency, but hey its early days and my power meters are not known good.

mw0uzo
08-04-2012, 07:10 AM
Turns out my high power meter reads low, output on 30/40m is 600W+, other bands excluding 10m ~550W. Capacitor value mod across transformer primary required for 10m operation.

NQ6U
08-04-2012, 08:05 AM
But...it ain't go no knobs on it!

mw0uzo
08-04-2012, 10:01 AM
But...it ain't go no knobs on it!You're right, there won't be any knobs on it at all, just an LCD display, pushbuttons and a few LEDs. F*CK

mw0uzo
08-04-2012, 10:03 AM
Will a random wheel on the front do, or am I gonna have to start again?

PA5COR
08-04-2012, 10:17 AM
That's thee minimum, even if it just controls the light of the display...

I love the SB-1000 large knobs plate, load, band, PWR, STdby Multimeter knobs...
Look at the Ft-2000 D with all its knobs, a dream come true here , KNOBS heaven ;)

NQ6U
08-04-2012, 10:37 AM
That's the ticket—a pair of knobs labeled "Plate" and "Load." Use a couple of old junque box pots or something. Everyone knows that a real radio has to have knobs; however, I do not think there's a requirement that they actually do anything.

K7SGJ
08-05-2012, 11:08 AM
That's the ticket—a pair of knobs labeled "Plate" and "Load." Use a couple of old junque box pots or something. Everyone knows that a real radio has to have knobs; however, I do not think there's a requirement that they actually do anything.

Hell, just Velcro them on. No holes, and you just pop them off to adjust the plate and load, then put them back on. Simple? Why, yes I am.

mw0uzo
08-05-2012, 04:30 PM
Mechanical construction of attenuator board. Board consists of 8 way standard relay board purchased from ebay. Underneath is a board of copper clad and mounted to that a heatsink for the attenuator resistors. Attenuators will be for 10W, 25W, 50W and 100W in.

http://s9.postimage.org/xyc64sbgr/SV203404.jpg (http://postimage.org/image/xyc64sbgr/)

http://s9.postimage.org/is64dulfv/SV203405.jpg (http://postimage.org/image/is64dulfv/)

I am likely to use the same construction for the LPFs with two further relay boards. I will have four relays left, two will be kept spare in case of addition of 6m operation, the other two will be the RX and TX switching relays. They're rated at 10A, 250V AC. I really don't know if they'll be good enough for use with such high power RF. But everywhere I look RF amps are getting away with tiny relays.

N8YX
08-15-2012, 07:05 AM
That's some nice work. If the overall concept could be adopted to the 6, 2, 1.25M and 75cm bands with an input power of 10-15w PEP and an output of 500w or so, I know just the shack which could use a few sets of those boots. :yes:

mw0uzo
08-21-2012, 05:44 PM
Few more pics and a bit more progress:

Better current sense module fitted
http://s18.postimage.org/98wj16eed/SV203407.jpg (http://postimage.org/image/98wj16eed/)

Mounting plate and piece of copper clad for the fast analogue current limit protection
http://s18.postimage.org/qngr9gbj9/SV203408.jpg (http://postimage.org/image/qngr9gbj9/)

Decided to use 120mm fan, also made up the bare LPF relay/copper clad modules
http://s18.postimage.org/y4pyoo12d/SV203409.jpg (http://postimage.org/image/y4pyoo12d/)

K7SGJ
08-23-2012, 06:23 AM
Very cool. Nice clean job.

NQ6U
08-23-2012, 08:25 AM
Very cool. Nice clean job.

Yes. I'm still concerned about the lack of knobs, however.

K7SGJ
08-23-2012, 08:46 AM
Yes. I'm still concerned about the lack of knobs, however.

Those will be on the sister chassis. I'm surprised that you, of all people, aren't aware of sister chassis.

mw0uzo
09-06-2012, 10:56 AM
Update with some problems discovered:

Made the analogue fast current limit detect circuit, works great :)
http://s15.postimage.org/5bxxfkuiv/SV203454.jpg (http://postimage.org/image/5bxxfkuiv/)

Found that the amplifier has a very low level spurious oscillation, approx 0.25-0.5W when it is attached to an antenna. :(
There is no oscillation when attached to a dummy load. This has been seriously puzzling me. Is it parasitic oscillation?

mw0uzo
09-06-2012, 03:19 PM
From RF Power Amplifiers
Iulian Rosu, YO3DAC / VA3IUL, http://www.qsl.net/va3iul

• RF PA oscillation problems can be broadly categorized into two kinds:
Bias oscillations and RF oscillations.
Bias oscillations occur at low frequencies, in the MHz to VHF range, and are
caused by inappropriate and unintentional terminations at those frequencies by the
bias insertion circuitry, such as the addition of a large-value decoupling capacitors.
The oscillations have little to do with the details of the RF matching circuitry, where the
RF blocking and decoupling capacitors become open circuit terminations at lower
frequencies.
RF oscillations, on the other hand, typically occur either in band or commonly out
of band but still quite close to the desired bandwidth from the low frequency side.
• Decreasing the low-frequency gain of a PA stage, which is naturally at an increased
level, will assist in amplifier stability.
• The unavailability of a sufficient ground-plane, or a ground-plane that is excessively
segmented, can create uncontrollable instability in a PA.

The last point is a known problem with the eb104. Perhaps the ground modifications will eliminate this problem, as the ground plane is 'excessively segmented'.

mw0uzo
09-11-2012, 11:12 AM
Ok done some ground modifications - added a strap across the fets and reinforced the grounding to the central part of the PCB. This has increased the amplifier efficiency :)

Also changed the 1200pF caps across the transformers to 820pF. This has given good operation up to 10m in exchange for a slight reduction in efficiency on other bands.

Unfortunately the low level instability is still there, I believe at 1.6Mhz. Interestingly its level seems to vary in proportion to the bias current. A clue maybe..

mw0uzo
09-11-2012, 12:10 PM
It disappears with a different antenna and also if an atu is inserted, using the same antenna. No spurious if ATU is tuned to 1.6Mhz either. Wonder if I'm chasing some sort of ghost problem?

X-Rated
09-11-2012, 12:42 PM
The dummy load is a basically a perfect antenna as far as the radio/feedline is concerned. The perfect antenna (as far as the rig/feedline are concerned) will have 50 ohms of resistance and no reactance. When you tune the antenna with an antenna tuner, you should be transforming the resistance to look like 50 ohms to the radio and cancelling out the reactance. These are two separate tasks performed in tuning the antenna and bringing the SWR to 1:1.

So I am not surprised at all that the spurious went away when you tuned the antenna. If it was gone into a dummy load, it should be gone with the ATU.

Now. What is causing it? Maybe it is biased incorrectly. It is possible that the one antenna looks like a higher impedance load and the voltage swing on the amplifier output is driven too hard. When the 50 ohm impedance is there then the voltage amplitude is decreased to within the desired load lines of the design.

One thing to try is with the one antenna being used where there is spurious, can you increase the DCV to the amplifier and watch the spurious levels if they decrease? If so, I would agree that the bias is off.

mw0uzo
09-11-2012, 06:27 PM
The dummy load is a basically a perfect antenna as far as the radio/feedline is concerned. The perfect antenna (as far as the rig/feedline are concerned) will have 50 ohms of resistance and no reactance. When you tune the antenna with an antenna tuner, you should be transforming the resistance to look like 50 ohms to the radio and cancelling out the reactance. These are two separate tasks performed in tuning the antenna and bringing the SWR to 1:1. So I am not surprised at all that the spurious went away when you tuned the antenna. If it was gone into a dummy load, it should be gone with the ATU. Now. What is causing it? Maybe it is biased incorrectly. It is possible that the one antenna looks like a higher impedance load and the voltage swing on the amplifier output is driven too hard. When the 50 ohm impedance is there then the voltage amplitude is decreased to within the desired load lines of the design. One thing to try is with the one antenna being used where there is spurious, can you increase the DCV to the amplifier and watch the spurious levels if they decrease? If so, I would agree that the bias is off.

Hey X-Rated, thanks for your reply :)

Yes I have a 1A 50V variable supply with which I could run some tests.

Reducing the amplifier bias from 250mA per device to 150mA reduced the spurious output significantly.
I will try 125mA tomorrow as another eb104 builder suggests 100-150mA and post back the results.

mw0uzo
09-12-2012, 09:08 AM
Reducing the bias to 120mA per device has eliminated the problem completely :D

X-Rated
09-12-2012, 10:01 AM
Reducing the bias to 120mA per device has eliminated the problem completely :D

That is great. I am glad that all worked out well for you.

mw0uzo
09-12-2012, 10:13 AM
That is great. I am glad that all worked out well for you.

Yeah, that really could have been hideous... BANG and/or feedback modifications required.

Thankfully, next step is to moving the controller from breadboard onto copper clad and fit it along with the LCD, switches, and status LEDs. Watch this space :)

X-Rated
09-12-2012, 10:24 AM
Yeah, that really could have been hideous... BANG and/or feedback modifications required.

Thankfully, next step is to moving the controller from breadboard onto copper clad and fit it along with the LCD, switches, and status LEDs. Watch this space :)

I have designed many low level transistor amps. Dozens of milliwatts. I have fought spurious before. It is usually a bias issue..

mw0uzo
09-13-2012, 09:41 AM
Screen fitted to front panel
http://s13.postimage.org/b9a2kx2r7/SV203456.jpg (http://postimage.org/image/b9a2kx2r7/)

Attached to breadboard controller
http://s13.postimage.org/v5620gjsj/SV203457.jpg (http://postimage.org/image/v5620gjsj/)

mw0uzo
09-16-2012, 10:58 AM
Partially complete display and controller module
http://s13.postimage.org/cqgesz69f/SV203462.jpg (http://postimage.org/image/cqgesz69f/)

http://s13.postimage.org/8iq7xyu7n/SV203464.jpg (http://postimage.org/image/8iq7xyu7n/)

PIC is 16F887. Two shift registers provide 16 outputs to drive the attenuator select signals, lpf select sigals, fault/warning leds and buzzer off two pins on the PIC.

NQ6U
09-16-2012, 01:44 PM
Partially complete display and controller module
http://s13.postimage.org/cqgesz69f/SV203462.jpg (http://postimage.org/image/cqgesz69f/)

http://s13.postimage.org/8iq7xyu7n/SV203464.jpg (http://postimage.org/image/8iq7xyu7n/)

Nice. You and Aussie Bob should get together for an amp-fest sometime.

mw0uzo
09-17-2012, 05:45 PM
Nice. You and Aussie Bob should get together for an amp-fest sometime.

I could learn a trick or two from his projects!! Too much red wine would be drunk to be able to make anything that might work though :lol:

Low power 10W swr board and little board for input overload protection. It will have a 500mA fuse and back to back 31V zeners so that anything over 10W (and the protection fails to operate) then the fuse will blow, disconnecting the amplifier.
http://s14.postimage.org/ikypg2ph9/SV203468.jpg (http://postimage.org/image/ikypg2ph9/)

Hole for hot air rear vent. Amp module is attached to rear and bottom of case. This stiffens up the case quite a lot, which is good as I was worried I was going to have to install some metal braces to stop the underside from bending with all the weight.
http://s14.postimage.org/ru0vq6yd9/SV203469.jpg (http://postimage.org/image/ru0vq6yd9/)

mw0uzo
09-18-2012, 11:04 AM
Huge RX/TX relay. Chosen because of having to handle 100W of hot switching RF input in RF sense mode. Also nice big contacts for switching the 600W of RF output. Output won't be hot switched, but might during development of PIC controller...
http://s14.postimage.org/pngprtjd9/SV203471.jpg (http://postimage.org/image/pngprtjd9/)

Fitted four SO239s to the rear panel, dual input and dual output.
http://s14.postimage.org/tl3zh866l/SV203472.jpg (http://postimage.org/image/tl3zh866l/)

RX/TX relay nestled into the corner
http://s14.postimage.org/6xoqb2qml/SV203473.jpg (http://postimage.org/image/6xoqb2qml/)

mw0uzo
09-19-2012, 10:36 AM
Input protection failsafe
http://s10.postimage.org/zeop0iobp/SV203474.jpg (http://postimage.org/image/zeop0iobp/)

Added four phonos on the back for PTT, ALC, TX inhibit and a spare
http://s10.postimage.org/ao3m0fycl/SV203475.jpg (http://postimage.org/image/ao3m0fycl/)

Added control buttons and status LEDs to the front panel
http://s10.postimage.org/rpwg2jd7p/SV203478.jpg (http://postimage.org/image/rpwg2jd7p/)

Yeah!!
http://s10.postimage.org/5rzz8qy79/SV203481.jpg (http://postimage.org/image/5rzz8qy79/)

X-Rated
09-19-2012, 10:44 AM
Very Professional.

mw0uzo
09-19-2012, 11:31 AM
Very Professional.

Thx :) Very pleased with it at the moment :D

She's got buttons to press and will have flashing lights, if I add a knob would that make her 'exotic'? Or just wrong :lol:

X-Rated
09-19-2012, 11:33 AM
Thx :) Very pleased with it at the moment :D

She's got buttons to press and will have flashing lights, if I add a knob would that make her 'exotic'? Or just wrong :lol:

Amps do usually cum with a knob.

NQ6U
09-19-2012, 02:13 PM
Looks awesome. It would look even more awesome if it had a knob but awesome is awesome. Nice job!

mw0uzo
09-19-2012, 05:57 PM
What do you think is the best way to make the front panel 'Nice'? Like an overlay or printed covering? I've never gone past putting small laminated white paper printed labels on things. There must be a better way? Part of me likes the bare metal and standard component look, it looks like homebrew. Maybe there should be a plastic printed front cover to give good decoration as well as providing scratch protection for the front panel.

K7SGJ
09-19-2012, 06:32 PM
Crayon

X-Rated
09-20-2012, 12:40 PM
Stencil. Silkscreen.

kf0rt
09-20-2012, 12:54 PM
Stencil. Silkscreen.


Agreed.

The professional construction seems to demand a pro labeling job.

mw0uzo
09-20-2012, 07:36 PM
Crayon

My daughter would love to be let loose with a crayon on the front of that. And all over it.

Looks like stencil silkscreen it is then, thanks for recommendation :)
Also might consider engraving/paint like those nice metal signs you see on industrial control panels...

mw0uzo
09-22-2012, 07:33 PM
First test SWR bridge. This may or may not find itself in the amplifier depending on performance. 3 of these will in use in the amplifier. Initial performance seems promising, put 100W through it with no heating. SWR just starts to rise at 30Mhz, probably due to layout and construction method. Seems able to detect low power as well as high. Output is about 3.6V at 100W. How high will it go? The 1n4148s are rated at 80-100v, so will it handle 600W?.....

Top of SWR board.
http://s12.postimage.org/p2ps6vna1/SV203488.jpg (http://postimage.org/image/p2ps6vna1/)

Underside of SWR board.
http://s12.postimage.org/z1aqtcwpl/SV203489.jpg (http://postimage.org/image/z1aqtcwpl/)

mw0uzo
09-22-2012, 07:49 PM
Quick calculation suggest that the output voltage near expected.

Vout = (Vpk@Power/TransformerRatio) - DiodeVoltageDrop

@ 100W = (100/25) - 0.6 = 3.4V

@ 600W = (245/25) - 0.6 = 9.2V
Vpk through diode is only 10V so should handle the power?

mw0uzo
09-25-2012, 05:22 PM
Wiring up the front panel
http://s7.postimage.org/3ulan2f2f/SV203497.jpg (http://postimage.org/image/3ulan2f2f/)

More work on the control board, added another 8 output and wired up the connectors, also additional power rails and headers for rx/tx relay and fan.
Spaghetti!
http://s7.postimage.org/az33w3mbr/SV203499.jpg (http://postimage.org/image/az33w3mbr/)

Almost hardware complete controller. All that is left to do is the ALC circuit.
http://s7.postimage.org/pjos4o6o7/SV203502.jpg (http://postimage.org/image/pjos4o6o7/)

Fitted the fan
http://s7.postimage.org/z5ickyxtz/SV203507.jpg (http://postimage.org/image/z5ickyxtz/)

Outside view of fan. Cut an octagonal hole as cutting a tidy 120mm hole was beyond my tool selection. Still looks OK, yes circular would have been better.
http://s7.postimage.org/uxnkc7wef/SV203508.jpg (http://postimage.org/image/uxnkc7wef/)

K7SGJ
09-25-2012, 06:14 PM
I may have missed it early on, but are you doing your own pc board layout and etching?

mw0uzo
09-25-2012, 06:28 PM
I may have missed it early on, but are you doing your own pc board layout and etching?No. If I were planning on selling the controller board as a kit then I may do a layout for the controller. Since this is a one off, the boards will be one off prototypes as well. I find it a lot quicker prototyping using the methods shown in the pictures than getting annoyed with CAD software. I spent 8 years battling various types of CAD software for work and cannot face doing it anymore.

mw0uzo
09-25-2012, 06:58 PM
Ok I tell a small lie, there are two of these as a friend is building one too. He would definitely like me to make a layout for the controller board :lol:

K7SGJ
09-25-2012, 08:02 PM
Ok I tell a small lie, there are two of these as a friend is building one too. He would definitely like me to make a layout for the controller board :lol:

Well, there is a hole to fill since Heath went away.

mw0uzo
09-26-2012, 05:19 AM
Well I tried ExpressPCB, put the analogue protection circuit in the schematic editor, then moved over to the PCB design software. After spending ages filling in all the definition 'holes' I discovered it doesn't autoroute :( Any more suggestions?

mw0uzo
09-26-2012, 06:07 PM
Fitted the high power resistors for the dummy loads. There are 100W 50ohm ones for each inputs and 5x100W 10 ohm ones for the output dummy load.
http://s7.postimage.org/67c4myrtz/SV203509.jpg (http://postimage.org/image/67c4myrtz/)

mw0uzo
10-01-2012, 11:55 AM
For any PCB work, I think I will probably use Proteus. I wonder what the demand for an amplifier controller kit would be? It could control any amplifier.

N8YX
10-03-2012, 07:05 AM
For any PCB work, I think I will probably use Proteus. I wonder what the demand for an amplifier controller kit would be? It could control any amplifier.
Design one up and throw it out for general consumption - see what kind of feedback you get. Perhaps a collaboration with Bob, VK3ZL is in order?

mw0uzo
10-29-2012, 02:01 PM
No tasty photos in this update, but...

Development of the controller is coming along:
* Implemented large menu system for amp control, settings and alignment. The page limits of the 16F series were a bit annoying here.
* Made the warning and fault detection/reporting system. The fault screen scrolls through the reported faults with a description and value of the ADC for each one.
* Made the sequencing timers, PTT and hang time functions
* Got the fan, display backlight and ALC pwm generators working. Made the fan speed variable according to temperature, with settable min and max temperatures

mw0uzo
11-03-2012, 07:36 PM
* Menu system complete
* PTT mode select menu and handling code done
* Hang time mode select menu and handling code done
* Setting and alignments menus done with saving of values to EEPROM
* Improvements to bargraph display code
* 5 different style monitor pages

Controller is ready for proper testing. Put into transmit mode and disconnected antenna - protection kicked in straight away, reporting each value that had gone outside the limits.

Started on the LPF modules. Drew out the layout on the back of the copper clad and cut it out with a cutting disk on a dremel.

Put most of the capacitors in
http://s12.postimage.org/oks0haidl/SV203563.jpg (http://postimage.org/image/oks0haidl/)

What it should look like with the wound inductors in place
http://s12.postimage.org/uzr1dyp3d/SV203564.jpg (http://postimage.org/image/uzr1dyp3d/)

N8YX
11-04-2012, 10:35 AM
Very nice. I'm tempted to build one or two for my FT-301 setups.

mw0uzo
11-05-2012, 08:56 AM
Very nice. I'm tempted to build one or two for my FT-301 setups.

If you do, you're welcome to a programmed PIC suitable for the controller. Hopefully by then it will be bug free and stable. I suspect the protection might be oversensitive at the moment, we'll see once I get the hardware in a state where I can connect up a radio, give it a blast and then be able to RX. That will be soon....:D

mw0uzo
11-06-2012, 06:56 PM
More work on the LPF module. Needs three more capacitors, some testing and maybe a few tweaks. Quick test show cutoff frequency of 30/20m lpf is too low...
http://s12.postimage.org/iti2yvmq1/SV203569.jpg (http://postimage.org/image/iti2yvmq1/)

mw0uzo
11-08-2012, 01:21 PM
LPF #2 and 2 output/dummy load switching module
http://s16.postimage.org/sjooc5nm9/SV203572.jpg (http://postimage.org/image/sjooc5nm9/)

http://s16.postimage.org/6ls7id8lt/SV203574.jpg (http://postimage.org/image/6ls7id8lt/)

N1LAF
11-12-2012, 07:41 PM
Ok I tell a small lie, there are two of these as a friend is building one too. He would definitely like me to make a layout for the controller board :lol:

Have you looked at http://www.4pcb.com/
PCB ARTIST
Top-Rated Free
PCB Layout Software!
Easy to Use and Intuitive...

Huge Library of Over 270,000 Parts!
Free Autorouter & Free Tech Support
Multi-Page Schematic and
Netlist Import
Gerber Format Available

N1LAF
12-01-2012, 08:28 PM
If you would like a professional looking schematic, I can put one together for you.

K7SGJ
12-03-2012, 10:02 AM
If you would like a professional looking schematic, I can put one together for you.


Schematic? He don't need no stinking schematic. He's a ham, he can use a road map of NYC as a schematic.

mw0uzo
12-04-2012, 04:38 PM
Heh, thanks for the offer N1LAF :)
A few more things to make on the control board before I draw it out on paper. You might get a scan of it....
Very busy with work at the moment so thats why no reply or any more updates with progress. Finished (I really hope!) the lpfs and fitted them to the case and wired up, so can transmit on all the different bands and monitor powers and swrs etc.

mw0uzo
12-04-2012, 05:10 PM
I had several problem with the LPFs that slowed progress. One band needed inductors played around with, another I missed soldering a capacitor and then I had RF pickup problems with the relay boards.
The big input TX switching relay seems to have a swr issue above 28Mhz, how annoying is that?!! Just a few more Mhz and it would have been ok..

N1LAF
12-08-2012, 09:01 AM
Heh, thanks for the offer N1LAF :)
A few more things to make on the control board before I draw it out on paper. You might get a scan of it....
Very busy with work at the moment so thats why no reply or any more updates with progress. Finished (I really hope!) the lpfs and fitted them to the case and wired up, so can transmit on all the different bands and monitor powers and swrs etc.

Scan away. I am ready. A good schematic will also be helpful in troubleshooting and enhancements too!

mw0uzo
12-09-2012, 12:50 PM
LPFs have been installed, RXTX relay replaced, SWR bridges wired up and controller updated. RF detect worked first time. Controller faulted at TX switch on due to SWR spike from switching the amplifier input. Added warning and fault mask function so that protection is not triggered for certain faults while switching from RX to TX mode. Added piece of coax to enable receive for the connected transceiver. A problem with the SWR calculations causes intermittent faults on edges of carrier transmission. Once this is fixed and I borrow a transceiver capable of very low power SSB, a first QSO will be possible!!!

mw0uzo
12-12-2012, 07:40 PM
Ok fixed the controller so several consecutive bad SWR readings are neccessary to cause a warning or fault. This has cleared up the intermittent faulting under SSB completely. Had an hour QSO with mw0kst on 17m at about 120w pep with no faults or problems :D

WØTKX
12-12-2012, 08:06 PM
And no smoke came out? :omg:

Kewl. :agree:

NQ6U
12-13-2012, 12:03 AM
Only 120 watts? Turn it up to 11, man!

mw0uzo
12-13-2012, 06:01 AM
And no smoke came out? :omg:

Kewl. :agree:

There is some RF pickup problem still on 21Mhz in the LPF modules, I cranked up the power to about 400W to see if the problem was still there, relays changed position and a scary sparking sound came from the amp. Protection kicked in immediately with a fast acting reverse voltage fault. No damage to amplifier. Some more work required to get rid of the problem, lesson learned though for next time, choose different construction method.


Only 120 watts? Turn it up to 11, man!

I really, really, really want to do that. Really.
There have been a lot of close shaves, accidentally transmitting into bad patch leads, forgetting to attach the dummy load, rf pickup causing unintentional switching of relays. The amplifier has survived these with only current limiting protection.
Now there is full protection, but a failure of the MRF150s would set the project back by months, lol it would probably take years to get over it...

mw0uzo
12-13-2012, 06:03 AM
For a short while I did have it at about 250W pep, but then a complaint from the wife arrived about the baby monitor making funny noises.

T|he other station checked his bandscope on his SDR radio and said it looked really clean :)

mw0uzo
12-18-2012, 04:29 PM
Added some temporary decals, also shows setup for first test QSO
http://s9.postimage.org/rdararf2z/SV203648.jpg (http://postimage.org/image/rdararf2z/)

Image showing fault protection screen, the software lists out all combinations of fault that occur and the ADC readings
http://s9.postimage.org/hu12harkr/SV203651.jpg (http://postimage.org/image/hu12harkr/)

Image showing SWR warning lamp lit from detecting a SWR above 2.0
These warnings stay lit so you dont miss them when not looking and can be reset via the menu.
http://s9.postimage.org/wei5c4mjf/SV203654.jpg

(http://postimage.org/image/wei5c4mjf/)Image showing 300W being put into the internal dummy load
http://s9.postimage.org/4fnzl9kwr/SV203655.jpg (http://postimage.org/image/4fnzl9kwr/)

Another alternative monitor screen
http://s9.postimage.org/qg4c1w3kr/SV203656.jpg (http://postimage.org/image/qg4c1w3kr/)

And another one, there are 8 different monitor screens!
http://s9.postimage.org/3sp2vqo0r/SV203657.jpg (http://postimage.org/image/3sp2vqo0r/)

N8YX
12-18-2012, 06:03 PM
Major (umpteenth) cool.

Good job! :agree:

NQ6U
12-18-2012, 06:31 PM
I'll take two!

mw0uzo
12-18-2012, 07:34 PM
Thx guys :)
Had a good few QSOs tonight on it on several different bands. Had a distortion problem on 80m at high powers, I think due to forgetting that the fast current protection is set really low for testing (bias reduces at ~300W).
Off to bed now, I might be able to do some more work on it after Christmas so I'll post some updated photos of the innards then.
Have a good Christmas and I hope you consume shocking amounts of alcohol :D
Dan

mw0uzo
01-04-2013, 05:49 PM
Current state of project
http://s8.postimage.org/o755s0881/SV203665.jpg (http://postimage.org/image/o755s0881/)

Changes since last photo of insides:
Built and installed LPF modules
Got rid of big RXTX relay, input SWR just started to rise at 28Mhz.

Things left to do preventing proper use:
* Attenuator module needs building and wiring in
* RF pickup problem in LPF modules, fitted bypass capacitors to control board but this had no effect. Next solution to attempt is to rewire the control lines using screened cable.
* 40m LPF SWR is too high, also a few interconnecting wires need to be changed to thin coax to reduce SWR at 30Mhz.
* Replace 3.5mm plugs to SWR modules
* Fit relay to bridge out main transformer inrush limiters. When the amp is cold and suddenly transmits a large amount of power, the protection trips with a low Vs fault.

Other features left to do:
* ALC
* Auto frequency detect

Firmware is working well, not had a single crash during recent testing :)
* Need to write peak detection for the power meters
* Fix some monitor screens so they actually work properly
* Make amp store its current state in EEPROM.

mw0uzo
01-08-2013, 09:30 AM
I think I've solved the RF pickup problem. Changing a 10k resistor to a 510 ohm in each transistor switch for each relay appears to fix the problem. I have also added some heavier duty ground straps between the lpfs and control board which has reduced rf measurable between the control board and lpf grounds.

mw0uzo
01-24-2013, 12:33 PM
Fixed RF pickup problems - confirmed. Modified relay boards to improve SWR at 30Mhz. Changed 3.5mm plugs for SWR modules.
Found some solder spheres on the 40m LPF. Removed them, but SWR is still highish (1.7) at the amplifier. However, now the SWR does not increase with power and the amp performs well at high power. I think I will leave it as it is and raise the pre-lpf SWR warn and fault levels.
Fitted cable to enable programming with amplifier case closed. Replaced all the thick RG-58 cables which were quite inconvenient to thin teflon coax - looks a lot better and amp is easier to inspect and work on.
Installed soft start relay.

http://s2.postimage.org/htfnhgdg5/SV203671.jpg (http://postimage.org/image/htfnhgdg5/)

Going to try some more test QSOs tonight to make sure its working properly.

mw0uzo
01-24-2013, 01:13 PM
I've got a gap in the middle. Wonder what to fill it with. A homebrew autotuner? That might be difficult to fit in that space.. plus a load more work. Maybe fill it with a plate for holding spare fuses? Any suggestions?

NQ6U
01-24-2013, 01:15 PM
Espresso machine? You can use the waste heat from the transistors to boil the water.

mw0uzo
01-24-2013, 03:29 PM
A very sensible suggestion, thx. Perhaps one of these as well?

http://www.lolr.de/2011/06/14/this-machine-destroys-everything/

mw0uzo
01-24-2013, 03:37 PM
Check this out: http://www.youtube.com/watch?v=sUtS52lqL5w
Sod the amp, its a pain in the arse, I wanna make one of these!

NQ6U
01-24-2013, 03:56 PM
Magnificent! 600 hours spent to build a machine to move a bunch of balls back to their starting point in as complicated a manner as possible. This is not unlike a lot
of the jobs I've held over the years.

mw0uzo
02-12-2013, 06:55 PM
Completed attenuator module with straight through (10W), 3dB (20W), 7dB(50W) and 10dB(100W) attenuators and switching relays for selecting two inputs into amp or into internal 100W dummy loads.
http://s18.postimage.org/8dfm937lx/SV203695.jpg (http://postimage.org/image/8dfm937lx/)

My quick and ugly construction method with lots of not so quick to strip coax. Not looking so good here, but it works. It's a facehugger!!!!
http://s7.postimage.org/rvg3vutef/SV203693.jpg (http://postimage.org/image/rvg3vutef/)

Trying to show the thick film power resistors sandwiched between the pcb and heatsink. The heatsink was tapped.
http://s7.postimage.org/xkwcg5zkn/SV203694.jpg (http://postimage.org/image/xkwcg5zkn/)

mw0uzo
02-19-2013, 07:30 PM
Progress:
- Attenuator module fitted and working. Wiring error meant it had to be taken out and corrected. Now I can use my ts850. Yay!
- Significant upgrade to firmware. Peak hold mode for all measured values, all user settings stored in eeprom and settings stored for each input selection.

Bad swr on 40m lpf turns out not to be 40m lpf at all. The amplifier is distorting or generating a larger harmonic on 40m resulting in the higher readings. While output is clean after the lpf - its doing its job properly - the source of the distortion has not been found. Increasing bias reduces the swr by a few points. 40m is the only band affected by this. Input is clean. Does anyone have any thoughts as to why this could be?

mw0uzo
02-19-2013, 08:14 PM
I may have found an answer. Apparently at 7Mhz, the 3rd harmonic is only 12dB down. This equates to 40w reflected at 600w, giving a swr of 1.7, which is the best of what I am seeing, 1.7-2.0. Perhaps normal... I hope...

mw0uzo
02-25-2013, 04:43 PM
More progress on the firmware - its at V1.0!!
- Monitor modes refined and fixed. All bar graph modes work properly now.
- Plenty of bugfixes

Used spare phono socket at rear for external bypass/standby switch for remote operation when used in a rack.

Image of amp with front panel removed
http://s9.postimage.org/5dysjt8uz/SV203701.jpg (http://postimage.org/image/5dysjt8uz/)

Image of completed LPF and attenuator modules
http://s9.postimage.org/n5aey9o9n/SV203706.jpg (http://postimage.org/image/n5aey9o9n/)

The amp is pretty much complete now. YEAH!

Some questions:

ALC - does it really need it, with the selection of attenuators available and the comprehensive protection?
SWR fault level - At the moment it warns at 2.0 and faults at 2.5 after 0.5s of continuous detection of bad swr. Is this too relaxed? (If there is a large spike of Vreflected, then it faults instantly)

K7SGJ
02-25-2013, 08:37 PM
That's a very nice piece of work. It's taken you quite awhile from start to finish, and you should be proud of the results.

mw0uzo
02-26-2013, 12:25 PM
That's a very nice piece of work. It's taken you quite awhile from start to finish, and you should be proud of the results.

Thanks :-D

A few pics showing whats on the display now:

Bypass mode screen showing power through, swr, antenna and input settings.
http://s23.postimage.org/x2byqcv6v/SV203789.jpg (http://postimage.org/image/x2byqcv6v/)

Monitor mode 1. 3 line mode, all relevant information in numerical form, menu visible always
http://s23.postimage.org/ix65ojm5j/SV203790.jpg (http://postimage.org/image/ix65ojm5j/)

Mode 2 - Power bar with no scale
http://s23.postimage.org/h6n4n24mf/SV203791.jpg (http://postimage.org/image/h6n4n24mf/)

Mode 3 - 4 line mode with power bar, scale and relevent numerical information.
http://s23.postimage.org/r5839je1z/SV203792.jpg (http://postimage.org/image/r5839je1z/)

The other modes are for debug and other monitor purposes, I got rid of the others as they were pretty much useless and poor resolution.

mw0uzo
03-01-2013, 07:54 PM
Note for the bias setting. Now the amplifier is complete there seems to be no problem with spurious output. Bias has been set to 1A total, which reduces SWR at LPF on 40m. Also, a 4.7k resistor has been added in series with the thermistor, the bias reduction was *way* too sensitive. The thermistor has also been moved from on top of one of the MOSFETs to the heatspreader. This gives sensible, flat operation of the bias wrt temperature. Interestingly a lot of people recommend that the thermistor should be in direct contact with the mosfet, e.g. on top, but in the original eb104 article it is recommended to be in contact with the heatspreader. From what I have seen, the bias behaves correctly when the thermistor is in contact with the heatspreader, not the MOSFET.

mw0uzo
03-01-2013, 08:04 PM
Also amp has survived extended TX of CW duty cycle at power level of 500W in my recent tests, so its looking good for plenty of 400W operation :)

Now only time will tell, I will post updates to this 'log' as it is used.

mw0uzo
03-02-2013, 11:47 AM
Contacts this afternoon on 80m at 400W pep. MW0KST, GW0JAI, M0CSV and G3IUW. Band suffering from lots of fading. No smoke though and cool operation of heatsink ~25-30 degrees.

X-Rated
03-06-2013, 12:29 PM
Can't wait till you get some DX there.

radioham
03-08-2013, 03:30 AM
Congratulations excellent construction.
It is possible to publish a diagram of the linear, maybe even a block diagram.
carlo IZ2ABZ

mw0uzo
03-09-2013, 07:54 AM
Can't wait till you get some DX there.

Done plenty of 80m Uk local over the past few days, with the MKARS80 qrp rig connected to the amp. Only got an antenna that works well on 80m at the moment, a 1/4 wave inverted L. When I get bored with 80m, I'll take down the L and put up a 40m dipole :)


Congratulations excellent construction.
It is possible to publish a diagram of the linear, maybe even a block diagram.
carlo IZ2ABZ

Block diagram will be posted soon.

For details of the amplifier module itself, see the EB104 application note
http://www.ab4oj.com/dl/eb104.pdf

Modifications done to amplifier
- Good quality RG58 coax screen used as grounding strap across the FETs
- Thick DC gnd to centre of board
- 4.7k resistor inserted in series with the thermistor to level off the bias temperature compensation
- High voltage large capacitors replace 0.1uF ceramics on PSU feeds to mosfets.
- 820pF caps across transformers

mw0uzo
03-09-2013, 11:36 AM
Block diagram for MW0UZO EB104 600W amplifier.
http://s22.postimage.org/hdher80wd/MW0_UZO_EB104_Amplifier_Block_Diagram.jpg (http://postimage.org/image/hdher80wd/)

radioham
03-11-2013, 07:39 AM
Thanks for the precious info.
Since I'm also building the fates would like a few questions.
The resistance from 4.7 k in series with the thermistor goes to sostiyuire the R10 (8.2 k).
The capacitor 820pF goes put in place of C11 (2 x 1200 pF).
Reading on the Internet I found that the capacitance C1 is made ​​from 68 pF to reduce the input VSWR, and C11 should be placed from 300pF to increase the power on 30MHz.
The supply voltage varies from 45 to 42 V to decrease the ROS, the current BIOS varies from 150 to 120 mA.
Which of these tips did you use?
From your block diagram I saw that you used 12 analog inputs on the PIC (the 16F877A has only 8 analog input) how did you do?
Why are there two 600W SWR Bridge?
Thank you very much.

Carlo IZ2ABZ

mw0uzo
03-11-2013, 10:23 AM
The resistance from 4.7 k in series with the thermistor goes to sostiyuire the R10 (8.2 k).

Yes it adds 4.7k to R10, for a total of 12.9k.


The capacitor 820pF goes put in place of C11 (2 x 1200 pF).

Yes, replace each one with 820pF.


Reading on the Internet I found that the capacitance C1 is made ​​from 68 pF to reduce the input VSWR, and C11 should be placed from 300pF to increase the power on 30MHz.

C1 is not fitted on my amplifier.I have only tried 820pF capacitors on the transformers, reducing them further may increase gain on 10m. However, you may reduce efficiency on 160m or 80m.


The supply voltage varies from 45 to 42 V to decrease the ROS, the current BIOS varies from 150 to 120 mA.Which of these tips did you use?

My bias is set at 250mA each for the amplifier, but I did experience problems when the amplifier was being tested by itself. I had to set it to 120mA each to avoid spurious output. Always a good idea to start testing with low bias, as it helps reduce gain and avoid death oscillations. My power supply voltage varies from 60V unloaded, to about 47V when loaded heavily. As my supply is linear (40V AC winding) and not easily adjusted, then I have done no tests with lower supply voltage. I chose to go linear to avoid any chance of RFI and because of doubts about the instantaneous current handling of an unknown SMPSU.


From your block diagram I saw that you used 12 analog inputs on the PIC (the 16F877A has only 8 analog input) how did you do?

I am using 16F887, 40 pin DIL, which has 14 possible ADC inputs.
I use 12 inputs:
AN0 - V
AN1 - I
AN2 - Temperauture
AN3 - ALC level detect in
AN4 - 10W Vf
AN5 - 10W Vr
AN6 - Out Vf
AN7 - Out Vr
AN8 - Amp Vf
AN9 - Amp Vr
AN10 - 100W Vf
AN12 - 100W Vr
with one spare for ALC level detect, which is not implemented.


Why are there two 600W SWR Bridge?

So that faults can be detected if something goes wrong with the LPFs. With only one SWR bridge a failure in the LPFs could kill the amplifier. The same applies to the 100W and 10W bridges, they are for RF detect and fault detection purposes. It is easy to get something go wrong in a large project like this.

radioham
03-12-2013, 04:31 AM
Thank you very much for the useful tips.
Add the resistors and capacitors suggested.
I immediately start to write the code for the 16F877 adding two SWR bridges suggested.
Carlo IZ2ABZ

radioham
03-12-2013, 05:06 AM
Sorry,
bat
- High voltage large capacitors replace 0.1uF ceramics on PSU feeds to mosfets.
Are C13 and C14? or C17 and C18?
regards
carlo IZ2ABZ

mw0uzo
03-12-2013, 06:36 AM
Sorry,
bat
- High voltage large capacitors replace 0.1uF ceramics on PSU feeds to mosfets.
Are C13 and C14? or C17 and C18?
regards
carlo IZ2ABZ

C13 and C14. I used some large HV caps out of an old TV, I think they were 0.22uF. They have a tendency to explode under fault conditions, and if RF is injected when the amplifier is off, a good proportion of it finds itself across these capacitors, via T2, so they end up dissipating power.

radioham
03-13-2013, 06:05 AM
Hi,
What are the characteristics of current and voltage of the relays.
Why in the EB104 uses 5V.
Why LPFs uses bands 30/17/12 and not, 20/15/10?
Best Regards
Carlo IZ2ABZ

mw0uzo
03-14-2013, 09:24 AM
Hi,
What are the characteristics of current and voltage of the relays.
10A 250V



Why in the EB104 uses 5V.
5V supply for the temperature sensor for the microcontroller.



Why LPFs uses bands 30/17/12 and not, 20/15/10?

My brain farted, yes they should be 20/15/10. The three LPFs are for 30m/20m, 17m/15m and 12m/10m.

radioham
03-15-2013, 07:13 AM
Many Tanks.
carlo IZ2ABZ

mw0uzo
03-15-2013, 08:23 AM
Many Tanks.
carlo IZ2ABZ

Happy to help :)

9100
woot, witch docteur :spin:

radioham
03-20-2013, 04:46 AM
Sorry for my bad English.
Many Thanks.
Carlo IZ2ABZ

PA5COR
03-20-2013, 06:31 AM
You will ge used to us nutters here Carlo, nothing wrong with your English, i b et most of us can't speak a full sentence in Italian ;)

K7SGJ
03-20-2013, 09:00 AM
Most of us can't speak a whole coherent sentence in English, either.

NQ6U
03-20-2013, 09:41 AM
Most of us can't speak a whole coherent sentence in English, either.

not tru me english speek gud.

K7SGJ
03-20-2013, 09:44 AM
I case my rest.

X-Rated
03-20-2013, 11:07 AM
Sorry for my bad English.
Many Thanks.
Carlo IZ2ABZ

We American hams normally say nothing about those who are good at English but make a few errors from other nations. You are welcome to post anything without having to be sure it is perfect English. I sure can't post anything intelligible in Italian.

NQ6U
03-20-2013, 11:25 AM
I sure can't post anything intelligible in Italian.

I could post a little bit in Italian, but it would be mostly insults I learned from my grandfather. And it would be in a dialect from southern Italy/Sicily, which would probably offend someone like Carlo, who is from Milan, even worse than the insults themselves.

WX7P
03-20-2013, 12:18 PM
http://www.youtube.com/watch?v=8iSD9lPVY6Q

KC2UGV
03-21-2013, 05:43 AM
Sorry for my bad English.
Many Thanks.
Carlo IZ2ABZ

No worries. I don't think you'll find many grammar police here :)

radioham
03-21-2013, 02:26 PM
Grazie a tutti
carlo

radioham
03-22-2013, 04:38 PM
Hello.,
you can post the project of SWR bridge are on page 7.
thanks
carlo iz2abz

mw0uzo
04-04-2013, 04:47 PM
http://www.kitsandparts.com/bridge.php

The SWR bridges are based on the above circuit with the following modifications
- Adjustment pots are across the Vref, Vfwd outputs with the wiper connected to the uc.
- The 47nF capacitors are replaced with 100nF and connected across the diode and gnd
- The 600W bridges have 25 turns, the 100W bridge has 20 turns

radioham
06-06-2013, 09:47 AM
Grazie,
Today I tested the my EB104.
I got my first 100W.
Thanks to the advice suggested.
many thanks
Carlo IZ2ABZ

978297839781

mw0uzo
06-13-2013, 11:21 AM
Haha! Excellent! It looks great!

2 modifications you will need to do:

Use thin coax for the connections from the RF input SO239 to the board. Wires like that will give you input SWR problems at 30Mhz. Probably best to add a small piece of coax for the output as well, although I only had problems with the input.

Move the bias compensation thermistor onto the heatspreader.

Next up will be the analogue fast protection and digital controller. Let me know if you want any info or help :)

Would be great if you could add your progress to my website forum as well, its only me on there talking to myself at the moment.....!
http://www.mw0uzo.co.uk/forum/phpBB3/index.php

radioham
06-20-2013, 02:02 AM
Thank you,
for the many tips
To check now I have written a program in MIKROBASIC (I started using it for about 3 months and my programming is at a basic level) that monitors temperature, voltage, current, and ros, and it changes the band with two buttons.
I use a 16F877A, I'm looking on the internet, some sample code to do to increase the inputs, because I wanted to have more opportunity to manage the relays.
Next week, maybe I'm going to Friedrichshafen, perhaps I see some ideas for my linear.
Will post my progress very happy on your site.

Carlo IZ2ABZ

mw0uzo
06-20-2013, 04:40 PM
I can send you the hex code for burning the controller. It will save you a years worth of hassle. I can put your callsign and a welcome message of your choice and convert the language to Italian with your help. The code is quite stable and is likely to be updated with new functions only a few more times, when I get round to doing them.

It was quite a challenge writing the code, there are a lot of problems to consider and fix. I would seriously recommend you use it.

radioham
06-28-2013, 12:23 PM
Thank you for the courtesy.
I accept the code.
I need also the pattern of micro and peripherals.
Carlo IZ2ABZ

mw0uzo
06-29-2013, 06:11 AM
Thank you for the courtesy.
I accept the code.
I need also the pattern of micro and peripherals.
Carlo IZ2ABZ

Ok, I'll draw out the skeleton of the controller and the circuit for the fast protection. It's quite simple the only additional circuitry for the uc are three 8 bit shift registers for providing 24 outputs from 2 pins on the uc. All outputs are logic level 5V as they drive readily available relay board from ebay with their own relay drive transistors. The fan is PWM controlled with a transistor switch from 12V. The display is a 4x20 low cost backlit LCD with HD44780 controller.

Get a few PIC 16F887 and start by prototyping everything on breadboard, get ISCP working etc first, then the display. The PIC is configured to use its internal oscillator for the clock. The controller will fault immediately upon power up as the ADC inputs will be all over the place as they are not connected. Don't worry when you get the display working you will be greeted by a PROTECTION FAULT message, this is good!

K7SGJ
06-29-2013, 09:52 PM
In my opinion, this is the stuff ham radio is all about. Kudos to both of you.

mw0uzo
11-19-2013, 12:35 PM
Carlo, for some reason your email isn't working. My response to your last email

Hi Carlo
PABIAS is directly connected, no relay
ALC adj ALC detect unused. Leave ALC adj open and ALC detect gnd.
The temperature sensor is 10k i think (the marking is on the contact
side :/), resistor is 4.7k, across 5V
Dan

radioham
12-15-2013, 08:20 AM
Ciao Dan,
I have seen the answer just now, I did not know of the problem to my email.
I'm finishing the card, I think that by the end of this month I also do functional testing, and if I did not commit the mistakes I mount the amplifier.
Carlo

radioham
12-25-2013, 05:19 AM
Merry Christmas Dan,
I did not understand the resistor 4,7K which is, and how to connect is.
Carlo

mw0uzo
05-27-2014, 05:15 AM
hey carlo,
been trying to reply to your emails, but for some reason your email server rejects them.
do you have an alternative email address?
I think I have been mistaken in giving you the temperature sensor details above.
I found a 20k NTC thermistor in my amp spares box - this is what I think I used. The thermistor will be connected to the +5V side as it reduces in value when it gets hotter.
I can put it in the post to you if you like, then it won't even need calibrating.
Dan

mw0uzo
06-03-2014, 09:05 AM
Carlo, I have ready for you personalised firmware for your amp controller. Please give me alternative email address to get in contact with you.

radioham
06-04-2014, 04:52 PM
Ciao Daniel,
I have send an email with email address.
I have used an NTC of 10k, is possible used this or is need buy an other NTC of 20k.
regards
carlo

2W0IWM
04-28-2015, 03:36 PM
Hi to everyone on the thread,

I'm a late starter here I'm afraid. I'm putting together an amp project, and I was wondering if it would be possible to join the queue for a copy of the controller schematic and the PIC code for your amplifier control board?

I'm only at a basic level with PIC programming, and it would save me a whole lot of headaches with the prototype, plus give me something to study as I learn.

thanks, Ian 2W0IWM

zs1adc
04-29-2015, 12:53 AM
Hi to everyone.
I've also just found this site and I'm very keen to build this linear. I'm not schooled in software at all but I love to build homebrew projects.
Dan if you still have the construction details of this project and code and can share it with me I'll love to build this linear.
Thanking you, Reg.

PA5COR
04-29-2015, 02:53 AM
I haven't seen Dan here for a long time, maybe it's better to send him a mail directly.

zs1adc
04-29-2015, 03:31 AM
Hi pa5cor.
Thanks for the info, I'll send him a msg on qrz.
Cheers, Reg.

2W0IWM
04-29-2015, 07:32 PM
Hi, thanks for that. I'll try via QRZ. He has an interesting website, but I can't find his email on there. QRZ next.
Cheers , Ian

mw0uzo
07-30-2015, 06:51 PM
Ooops missed all these posts, been off air for ages.
Get me at my call in lower case at gmail dot com
Sorry this is months late

PS. Hi all :)

PA5COR
07-31-2015, 03:09 AM
Better late as never, welcome back ;)

mw0uzo
07-31-2015, 04:53 AM
Better late as never, welcome back ;)

Thanks Cor :-D
Demands of life have kept me off air, off projects etc. Slowly battling through all the things that need to be done. For the first time in ages (a year?!) I worked on a radio project yesterday. Might see if I can do some today too, so the interest is returning. Its a 160m 40W transceiver, here's a pic of the amp module that fits on the back which needs fixing. 4xIRF510 push pull.

14197

G4ZOW
10-05-2015, 03:03 AM
I believe the 530's offer a little more power out even at 12V and for the same price.

David

PA5COR
10-05-2015, 12:09 PM
Sometimes you use what is at hand, I still have 10 IRF 510's here new in box for projects.
I'm past the time in life other things pull me away from home/hobby, though the usual chores need working on as usual.
Good luck with the project, call home ( here) a bit more often ;)