Anti-Kenwood rant

[N8YX]

Not so much against the performance of the gear itself, but of some questionable construction practices.

To wit:

Spent the majority of last evening troubleshooting a problem with an R-820 which somehow "migrated" to another one. Out of a total of three that I own, two are currently on the bench getting refurbed. One was working, and the other's modules (PLL, counter, oscillators, etc) were tested one by one in the 'good' chassis to make sure they operated correctly. All except the IF-A module, which contains the various crystal filters. When I put the "suspect" radio's original IF-A board in the known good rig, said rig no longer works....and I get a nice pronounced hum through the speaker.

Tearing into things further, I find that any substantial load placed on the 14v line now causes this symptom. It was intermittent but now it's permanent.

Hmm... :chin:

Tracing back through the schematics, I find the 14v rectifier assembly (which supplies power for the entire rig) is composed of 4 discrete diodes and is mounted on the friggin' band converter board! :shock:

When I extracted said board, I find that I2R losses have enabled a couple of the diodes to partially unsolder themselves, thus reducing a full-wave bridge to a fraction of its former self.

But Wait! There's More(ons)!

Kenwood's designers also thought it would be "efficient" to use part of the board to mount a couple of solder posts that connect 115-230VAC to the rest of the rig, and one serves as a tie point for the hot end of a line-noise suppression capacitor. It's located very near the diodes, and when they heated the board up they caused the terminal to become partially unsoldered...which accelerated its own I2R thingy...

Rant:

Why in hell can't some firms eat the 35 or so cents a terminal strip costs and do a discrete bridge rectifier assembly correctly by means of mounting it directly to the chassis? Failing that, why in hell can't some firms eat the dollar or so cost for the part and use a monobloc bridge rectifier and heat-sink the damned thing to the rig's chassis?

:evil: <- This is my "Pi$$ed-off" face

/rant

As Kenwood produced it, the board's design is also somewhat of a fire hazard. I'm giving serious consideration to a redesign of the whole area... :wall

In retrospective, I suppose I was lucky that the bad board created a condition which drew my attention to a potentially serious flaw...

[kd6nig]

If I had to bet money, I bet you'll find similar circuitry in all of their items that require said voltages.

Its probably something they use across the board, and they figure "it works in a car stereo, it will work in a ham radio!"

[N8YX]

If I had to bet money, I bet you'll find similar circuitry in all of their items that require said voltages.

Its probably something they use across the board, and they figure "it works in a car stereo, it will work in a ham radio!"
I wouldn't doubt it. Over the years, I've seen a number of "questionable" design concepts re-used throughout a given manufacturer's product lines.

An old (now retired) boss of mine could tell you some interesting stories about one of his former employers and their cost-cutting "measures" ... :whistle

[N8YX]

Found and fixed another problem. This is applicable to both the R-820 and its cousin the TS-820S:

On the underside of the receiver is a board with a handful of components, including two 2000uF, 25WVDC capacitors. One filters the main 14vdc line; the other, a 9vdc line. These are rather largish caps and are held to the board by virtue of solder alone. Wiggling one will crack the foil traces which connect it to the balance of the circuit. Vibrating the capacitor over the course of many years will also cause the foils to crack. I'm not surprised this happened, given the number of times that radio has followed me from 'Point A' to 'Point B'.

Yaesu did this better: A bit of glue was used on the base of each large cap to impart mechanical stability.

Receiver #2 is well on its way to being restored as well. After cleaning up a sloppy repair job on the 'filter' board, I poked around the AF-AVR board with a voltmeter and found that the 9V regulator's pass transistor only had 2 of its 3 legs soldered to the foils. That extra leg is there for a reason ... :doh:

[N8YX]

Update - a little Peter Gabriel is in order:

"The more I look...the more I find;"

Had a dim readout tube which would brighten randomly, and one of the digits would alternately flash its segments. Doing a little poking around, I found

- Cold solder joints on the display connection headers;
- Cold solder joints on the AF-AVR board;
- Cold solder joints on the counter mixer board;
- A bad .33uF tantalum cap on the counter mixer board;
- A broken terminal inside the display connector

Fixing the above took me most of this evening. Yesterday, some crystals I had ordered via eBay showed up and I swapped out three of the stock band crystals - two in the PLL unit and one on the converter board - for the new arrivals.

The set covers 6.5-7.0, 7.5-8.0 and 26.5-27.0 in the new ranges.

Also got rocks for 12M and 30M in the mail, but those are going in another TS-820S/R-820 pair.

Most of the electrical issues have been sorted. Just need a few parts along with a shield for the filter unit (which I'll build) and the receiver is ready to be reassembled then placed in line with its siblings.

[KB3LAZ]

Update - a little Peter Gabriel is in order:

"The more I look...the more I find;"

Had a dim readout tube which would brighten randomly, and one of the digits would alternately flash its segments. Doing a little poking around, I found

- Cold solder joints on the display connection headers;
- Cold solder joints on the AF-AVR board;
- Cold solder joints on the counter mixer board;
- A bad .33uF tantalum cap on the counter mixer board;
- A broken terminal inside the display connector

Fixing the above took me most of this evening. Yesterday, some crystals I had ordered via eBay showed up and I swapped out three of the stock band crystals - two in the PLL unit and one on the converter board - for the new arrivals.

The set covers 6.5-7.0, 7.5-8.0 and 26.5-27.0 in the new ranges.

Also got rocks for 12M and 30M in the mail, but those are going in another TS-820S/R-820 pair.

Most of the electrical issues have been sorted. Just need a few parts along with a shield for the filter unit (which I'll build) and the receiver is ready to be reassembled then placed in line with its siblings.

Sledgehammer or shock the monkey? :lol:

[W6WBJ]

'YX, this receiver is now OVER 30 YEARS OLD, yet you are surprised that it needs a few repairs?

Do you have any cars that are over 30 years old? Did they ever need any repairs? Did you rant about them, too?

I think this is a good example of why so many people hate to do business with hams.

[N8YX]

'YX, this receiver is now OVER 30 YEARS OLD, yet you are surprised that it needs a few repairs?
Quite frankly, yes, and not so much due to design deficiencies as to poor fabrication techniques - at least in the two units I have on the bench. I own a number of Kenwood hybrids and none of the others show signs of cold solder joints and other 'issues' which I'm finding with these two.


Do you have any cars that are over 30 years old? Did they ever need any repairs? Did you rant about them, too?
Your argument is somewhat disingenuous, because (as we both know) cars were NOT designed by their manufacturers to have a long life span. Now on the other hand...I have a friend who owns a 1915 Harley J. It has been on the road for the last 25 years, with nothing more than fluid, plug and drive-belt changes...tires, cables and whatnot. And it's ridden quite a bit for a machine of its age.

I mentioned "sundry items" when referring to the Harley. In a radio sense, changing or replenishing that stuff would be considered the equivalent of re-lamping, re-tubing and aligning a rig...and not having to correct a piece of equipment which was the output of an evidently flawed manufacturing process .


I think this is a good example of why so many people hate to do business with hams.
The crew at Elecraft would tend to disagree with you, but there's a reason why their company will eventually unseat all of the major "players" in that space.

Further: If a company cannot produce equipment which incorporates proper engineering, materials choice and/or fabrication techniques in an effort to achieve an MTBF that is as long as practically possible then they deserve to go out of business. Gear isn't being marketed now as "disposable", and it certainly wasn't marketed as such in the period we're discussing.

Drake and Cubic both were caught in a conundrum: Rather than reduce the quality of their amateur gear offerings to meet the price point of their Japanese competition, they pulled out of that market altogether and focused on the commercial and military markets. If you've ever been inside a TR7 or an Astro 103 you'll understand how "quality" amateur gear should be executed. Ditto the Signal/One line and a couple others.

Both of these companies used double-sided, glass-epoxy, silver-plated through-hole board technology while Kenwood used phenolic, bare copper, conformal-coated boards in their equipment. Kenwood's choice of connector headers (moreover, the tin plating used on them) along with the choice of solder and board fabrication technique almost guaranteed a rash of cold solder joints.

But only in some production runs. Perhaps someone wised up? Or maybe some cost-cutter got what he or she thought was a deal on raw materials and ended up staging a future failure by means of improperly wetted joints.

This phenomenon tends to repeat itself throughout Kenwood's model lines, so IMHO it's not a chance occurrence. Evidently, someone isn't thinking all of the angles through...

Meanwhile...my Drakes, Cubic and FT-901 lineups continues percolating along with minimal maintenance. Yes, the Molex KK156-series connectors need an occasional shot of DeOxIt but one of these days I'll probably replace them all with gold-plated versions. And that, folks, is the ONLY recurring problem with Bob Senior's products.

Did I mention I that I own later-model Kenwood stuff as well? And that I have to keep fixing the display headers on the VHF/UHF rigs? And that I had to recondition and rebuild the VCO circuits in my TS440S/R5000s due to (you guessed it) yet another implementation screwup.?

To Kenwood's credit, they have gotten a bit better as of late. Some of the other manufacturers are beginning to pull some pretty bone-headed moves when it comes to design. Witness the PA driver transistor arrangement in select late-model Icoms ... :roll:

[PA5COR]

10 year daily use of the FT 847
On/Off switch busted, new one will be put in next weekend.




That's all

The modifications are no repairs.

[N8YX]

10 year daily use of the FT 847
On/Off switch busted, new one will be put in next weekend.




That's all

The modifications are no repairs.
That's the thing about most (but not all) Yaesu equipment: It just tends to work.

I can think of a few exceptions, the FT736 and its questionable internal power supply being one of them. If you run the rig from an external supply, even that isn't an issue.

[KF2M]

Update - a little Peter Gabriel is in order:

"The more I look...the more I find;"



Sledgehammer or shock the monkey? :lol:

Actually it was "Digging In The Dirt"

[KB3LAZ]

Update - a little Peter Gabriel is in order:

"The more I look...the more I find;"



Sledgehammer or shock the monkey? :lol:

Actually it was "Digging In The Dirt"

You missed the funny.

[N8YX]

You missed the funny.
Some of us didn't. ;)

[KB3LAZ]

You missed the funny.
Some of us didn't. ;)

I know.

[n2ize]

'YX, this receiver is now OVER 30 YEARS OLD, yet you are surprised that it needs a few repairs?


I've got a few rigs that are well over 50 years old and you don't find the cost cutting design flaws that he's talking about here.



Do you have any cars that are over 30 years old? Did they ever need any repairs? Did you rant about them, too?

I think this is a good example of why so many people hate to do business with hams.

No, this is a good example as to why some companies need to rethink their cost cutting measures.

[n2ize]

10 year daily use of the FT 847
On/Off switch busted, new one will be put in next weekend.




That's all

The modifications are no repairs.
That's the thing about most (but not all) Yaesu equipment: It just tends to work.

I can think of a few exceptions, the FT736 and its questionable internal power supply being one of them. If you run the rig from an external supply, even that isn't an issue.

My Yaes\u FT-470 dual band handheld was VERY problematic. I had it back to Yaesu at least twice for repairs and several repairs I did myself. It was a nice radio WHEN it was working right. The last breakdown occurred in 1993. The vhf power amp crapped out, I still haven't replaced that module.... maybe one of these days I'll rebuild that little radio.

[N8YX]

My Yaes\u FT-470 dual band handheld was VERY problematic. I had it back to Yaesu at least twice for repairs and several repairs I did myself. It was a nice radio WHEN it was working right. The last breakdown occurred in 1993. The vhf power amp crapped out, I still haven't replaced that module.... maybe one of these days I'll rebuild that little radio.
Adding an update:

Worked on another of my R-820s this weekend chasing (yep, you guessed it) a cold solder joint. This in the FIX Ch circuitry; wouldn't let VFO output through it and into the PLL assembly. Thus, an intermittent display and receiver...which finally went solid OFF.

I suppose the ultimate fix will be to replace every one of the Molex SIP headers with a gold-plated equivalent then retouch all of the discrete components' solder pads.

Meanwhile...I've started modding one of my two FT-901DMs. First up is the RF board; I'm going to convert it to a DBM/JFET design per LA8AK's research. Looking at that 30-year-old board, one finds...joints as shiny and fresh as the day they rolled out of the factory.

Yaesu did a lot of things right in the early days, while Kenwood's choice of components and fabrication techniques continues to bite them right up through the TS-950 series and beyond. Anyone who has spent time resoldering all the SIP headers on a TS-940S' PLL CCA will attest to what I'm saying.

[W1GUH]

This reminds me of 1980 when I was deciding between a TS-180 and an Icom '701. A guy in a ham store in, I think it was Melrose, MA (Forget the name, but it was well known at the time, also not sure about the Melrose :-?: ) said that the TS-180 was "delicate" (I guess he meant won't stand up to being a mobile rig), whereas the Icom was solid. Sounds like you're expreiencing what he was talking about. OTOH, just to balance things out, the reviews over on eHam say the TS-180 is a solid radio.

The clincher was when he told me that the winner of the DX contest that year used the '701!

Getting back on the air after a break in 1980 was eye-opening. At that time I finally had the ways and means to go top-end, and of course, going into the process I had Collins and Drake in mind. I looked at the TR-7 and the KWM-380, the TS-180 and the IC-701. This is what I saw...

The TR-7 struck me as a transistorized TR-4. Basically the same system thinking went into it as went into the hollow-state radios. Analog PTO & pretty much the same operator controls as the hollow state stuff.

The KWM-380, while more advanced technically, seemed to miss the point -- the power supply was built-in and it wasn't a mobile radio.

Then there was the IC-701. It looked as if Icom's thinking went much farther than "transistorizing" a hollow-state radio. Their thinking was to brilliantly exploit modern technology to the limit without being limited by what had gone before. It saddened me that they pretty much beat the pants off of US radio makers in that respect. :(

This is when I reallized in a very concrete way that the "gotta make those quarterly reports look good" thinking in US Corporations was really, really, really stifling our ability to stay technologically abreast of the latest developments. The kind of R&D bucks that Icom spent to develop the '701 were just not possible here. :angry: :(

[KA5PIU]

Hello.

I have the TS-430.
That radio is clearly consumer grade.
The final transistor solder connections have gone bad, a known problem.
The light bulbs are in a bad position and hard to replace.
Some regulator circuits are/were taxed to the limit.
There are a few other things I can not think of right now.
But, for all of the faults, and they can be easily repaired, it is a good radio.
I had a TR-2500 talkie.
The LCD went "black" over just a year of use.
The chassis had a weak spot in the corner by the antenna connector that broke.
The backup battery died within a years time.
And the radio quickly became case-worn, the plastic simply being "painted" a color.

Contrast this to the FT-107.
This radio works much better and is better built.
The IC-3AT talkie I have still works very well Thank you.

But, we are hams, we can fix this, make it better.
That is but one part of the hobby, and what makes this all worthwhile.
And, yes, the Elecraft is one hell of a nice radio.
I really like the FT-817, if only for its size to abilities ratio.
But, if I want really tough I look at military hardware.
Remember, Amateur Radio equipment is built to a price.

[N8YX]

Remember, Amateur Radio equipment is built to a price.
And that is exactly what did Drake and Cubic in. They couldn't cut corners enough with regards to manufacturing techniques to compete with the Japanese manufacturers...and rather than risk the hit for warranty claims brought on by substandard goods, they opted to pull out of the market.

'GUH, the TR-5 is essentially a transistorized TR-4...whereas the TR-7 was a totally original design. Drake could have offered an amateur version of their TR-4310 and R-4245 to the general public but it would likely have cost $500 or so more than the PTO-tuned versions of such.

A little comparo:

My TS-820S retailed for ~$1200, and the TR-7 fetched $1449. The '820 had a speech processor and noise blanker built in; those were extra options on the Drake equipment. The TR-7 had it over the Kenwood in that a general-coverage receiver was offered but most hams didn't care.

The Kenwood actually drifts less than the Drake: 400hz total vs ~1.2 khz from a cold start. (Of course, the '901 beats both hands-down: Zero drift, once warmed up.)

I've done a little perverse engineering where the RV-75 and R-4245 are concerned...looking at synthesizer layout...and have come up with a way to shrink the RV-75 using SMT devices to a size which will enable it to fit into the TR-7's PTO space.

Another approach is to use a PIC or STAMP to control a DDS and thereby generate a 5.0-5.6 MHz VFO signal. This offers the advantage of being computer-controllable. I have a working prototype of a design on my bench, and have to write some firmware to control the tuning via an attached optical encoder. Mine also incorporates a workable RIT.

Maybe I'll get around to building one or the other type and stuffing all my 5 and 7-line equipment with them... :yes:

[AF6LJ]

This is a really good thread, I have found much of what the autor has discussed in my 820.
I might point out; having worked on Kenwood stereo gear I find the construction practices to be much the same including the tacky treatment of mains power.

In my own thread in the Homebres and Mods section I will post my experiences with reworking the 820 VFO which I am a little disappointed with.

Really who in their right engeneering mind would put ALL the inductance in a VFO tank on a slug tuned form.

They only do that in tailor parks.

[KA5PIU]

Hello.

If somebody came up with a DDS module that was small and generic (programmable) enough it would be a really neat upgrade for a lot of the older radios.
The trouble with older radios is both drift and crystal availability.
This would be so neat, swell even.

[N8YX]

Hello.

If somebody came up with a DDS module that was small and generic (programmable) enough it would be a really neat upgrade for a lot of the older radios.
The trouble with older radios is both drift and crystal availability.
This would be so neat, swell even.
Have a look here:

http://www.amqrp.org/kits/dds60/

http://www.amqrp.org/kits/dds60/dds60-top(400).JPG

All that's missing is a controller to transceive a 40-bit control stream (5 bytes total) and you're good to go.

I've looked into doing this with a PIC and with a BASIC Stamp. I actually have a working prototype put together with the latter; it uses a Grayhill optoencoder in quadrature-output mode for determining direction and rate of tuning. The Stamp I'm using has a clock frequency of 20MHz, which puts its oscillator right smack in the middle of the HF band...something I'm not too happy with. Thoughts are to use the BS2px (shown below) which has a 32MHz clock in place of the original unit. I don't know how much code I'm going to have to modify, though.

http://www.parallax.com/Portals/0/Images/Prod/B/BS2PX-IC-M.jpg

Both of these boards can be tucked into a very small space. The Stamp also allows me to emulate the K3 or TS-570 protocol for computer-control purposes, which is something you cannot easily do via a PIC-based controller.

The circuit I've come up with also uses an 8-bit serial ADC to implement RIT. Given 256 possible values, I can get +/- 1.28KHz adjustment if I tune in 10Hz steps. Another ADC can be used to read the AGC voltage through a buffer and thereby supply the controller program with an "S"-meter readout ... :yes:

[W5GA]

Remember, Amateur Radio equipment is built to a price.
And that is exactly what did Drake and Cubic in.

Actually, in Drake's case, I believe the cause was the company founder (a ham) died, and the kids had no interest in the market.

[N8YX]

Remember, Amateur Radio equipment is built to a price.
And that is exactly what did Drake and Cubic in.

Actually, in Drake's case, I believe the cause was the company founder (a ham) died, and the kids had no interest in the market.
Ahhh....no.

One of my coworkers is ex-Drake; he was involved in the TR7/R7 and TR5 projects and a lot of their satellite stuff. Management realized two things during the early to mid 80's: Fabrication costs - keeping the quality standards relatively high - compared to the Japanese sets really cut into Drake's bottom line; 2) The ham community at large was beginning to shun the 'Made in America' labels in favor of the all-in-wonderboxes. This is why the surviving clan "...had no interest..." in pursuing further ventures in the amateur market. Money is money, and if the amateur equipment market would have have been as easy to turn a profit as the satellite receiver market was at the time, they would have stayed in the game.

The decision to exit was purely business, not lack of interest.

[kf0rt]

Remember, Amateur Radio equipment is built to a price.
And that is exactly what did Drake and Cubic in.

Actually, in Drake's case, I believe the cause was the company founder (a ham) died, and the kids had no interest in the market.

Don't think so....

This is from an article by Bill Frost:

The postponed, but eventual decision was made to cease production of amateur radio equipment. The market had all but disappeared, there was a lack of FCC deregulation, the foreign competition was increasing more and more, and the dollar was strong.

Here: http://www.hamradio.no/la3tq/drakehis.htm

In fact, the R8 receiver was still produced until 2005 - 30 years after R.L. died.

The Drake Company today:
http://www.rldrake.com/index.php