The TS-530/830 mod and upgrade thread

[N8YX]

Hope its ok to add to this spectacular thread.

By all means. Everyone doing work on one of these rigs should document and post the results here.

[KA2PTE]

I pulled an L5 from a spare AF-AVR PCB that went to a TS-830S. It measures 2.87mH on my tester
and its got this number stamped on the metal band: L15-0016-05. Searching online for that term reveals its used in
some other later Kenwood riggs. It does not look burnt or overloaded, so installed it into my 530S's PCB. Have not powered up yet
but I am guessing it will be fine.

Tip #10 - Improve the TS-530 power supply filtering

The choke used in the '830 line (and a number of other Kenwood rigs) in P/N L15-0016-05. No data appears about this part online, though it's available to order from PacParts. I dug into my junk box and found a few chokes of the same form factor; these had been salvaged from CB sets over the years. Using the LCR bridge with a 120Hz test signal, I inspected the lot. Of them, I selected an 8mHy part; it had a measured Q of 3.6. The windings look to be good for 2-3A, which jives with an SSB CB's power requirements.

[KA2PTE]

Tip #6: Product Detector upgrades

- R41 is changed from 6.8K to 2.7K
- C35 is changed from .033uF to .01uF. This is a polystyrene unit
- R42 is changed from 47K to 3.9-4.7K (I used 4.3K)
- D16-D19 are changed from 1N60 to 1N6263 or similar Schottky parts. I got a bunch of these from K4EAA and matched them to .001v forward drop before installation


A 100 ohm, 1/4w resistor is added from the junction of R39 and R40 to ground:

Ok decided to try this mod on my 830S. It seems to me the area on its schematic is near D20-D23, which are all 1N60 type diodes. I have taken a photo showing them on the pcb.

HPIM0810.JPG

R42 in the 530 seems to be R78 and R41 is R77, but its already been changed to 2.7K in the 830S.
C63 in the 830 appears to be the same component as C35 but its been lowered to 0.022.

Not sure if I ought to change them to match, and from what I can tell R75 and R76 are the equivalent to R39 and R40
and when you follow the connect trail, there's no termination resistor I can see.

UPDATE: I terminated the product detector via R75 and R76 to ground with the 100 ohm resistor, put everything back together for a listen.
It does sound improved on rx somewhat and I am told audios good so I guess it was a success.

This is a photo of the 100 ohm resistor terminating on the foil side:

HPIM0813.JPG

[N8YX]

Excellent.

I'll keep the thread hijacks/hijinks to a minimum but I strongly suspect my NRD-515 receivers can benefit from this mod as well - and by having their AGC detector diodes swapped for a properly biased Schottky part.

Back to our regularly scheduled Kenwood goodness. I'm going to drag my '830S out of its shipping box in the near future and start doing some upgrades to it.

[KA2PTE]

Interesting, because I noted there are lots of other 1N60 diodes in these Hybrids, but not sure of their circuit function. The 1N60 is a basic germanium diode it seems.

Excellent.

I'll keep the thread hijacks/hijinks to a minimum but I strongly suspect my NRD-515 receivers can benefit from this mod as well - and by having their AGC detector diodes swapped for a properly biased Schottky part.

Back to our regularly scheduled Kenwood goodness. I'm going to drag my '830S out of its shipping box in the near future and start doing some upgrades to it.

[KA2PTE]

As per AG6K's page on somis.org :

Rapid jumps in VFO frequency. Cause(s): [1] This can be caused by fluctuation in the 9V regulated power-supply voltage, which is the result of an intermittent connection between the AF-AVR [automatic voltage-regulator] Unit's circuit-common and chassis ground. Fix(s): [1] Solder a wire to the "TPG" terminal, next to C81, on the AF-AVR Unit. On the other end of this wire, solder a #6 ground-lug with locking teeth. The ground-lug is placed under one of the nearby sheet-metal-screws that fastens the AF-AVR Unit to the chassis.

An alternate method, if you are already doing other work on the board is to merely scrape off the coating at (2) locations
on the foil side and make solder jumpers. This will effectively bring the floating ground condition permanently to a
hard wired ground coming in on the +40V line for the power transistors. That way if over time the screw loosens, its irrelevant. This photo shows the procedure, works on both AVR boards in either radio.

HPIM0814.jpg

[KA2PTE]

The OMRON branded relay on the 530s's IF pcb, the same kind used on the 830's AVR board is a well documented point of failure in both radios mostly for rx issues. There is a solution for the obsolete relay out there on K4EAA's site, however I chose to carefully and painstakingly clean my relay contacts in both radios with a nail file and compressed air. It took 2 attempts but I got the relays working again and so far for many months, there's no issues. Of course I dont do much CW, but I imagine during CW operation, these relays take a pounding and that could be why they are prone to faults.

Also, its well known that the coils on any relay will produce a high voltage counter_emf every time voltage is removed. Snubber diodes are usually placed on the coils to absorb the voltage so its not applied to the circuit design. However over time snubber diodes will get tired and develop hard to spot breakdowns of the junction reverse bias which could cause the relays open and close time to be effected. While I was working on my AVR board, I decided to change D10, the snubber as a maintenance item. I upgraded it to a new motorola 1N4003 series diode I had in my parts bin. While the original 1S1555 diode is lower current and faster switching, the 4000 series diode will take more abuse, so I tend to like this approach. The only drawback may be the 4000 series is rated at a slower reverse switch time then what its replacing, but I dont think its great enough than the actual open and close time for the contact, unless someone hooks up a cw bug and tries 100wpm code.

I took photos showing D10 on the 530S's AVR board, before and after the swap.

Before HPIM0815.JPG After HPIM0816.JPG

On the 830S, the Diode is D27 and is right next to the OMRON relay in plain view. Apparently they moved the relay from the IF board to the AVR board in the 830S.

HPIM0817.JPG

In the past I have seen relays in other gear fail due to the snubber actually reading like a resistor after many cycles. This could be because the diode itself was cheaply or poorly made or the counter EMF somehow exceeded the diodes rating.

[KA2PTE]

I wound up with another 530S and am giving it a going over with these procedures. So far so good.
Wanted to make a note that I got bit with the plate voltage that goes to the driver tube when I touched
the rear bandswitch wafer. Turns out on the rectifier board, R9 (330K) was completely open, its the bleeder
resistor for that supply and its a common fail in many of these, so if you are going into this board, check or replace.
Also the (2) 56K half watt resistors on the board forming a voltage divider also drift pretty far out of tolerance and
ought to be replaced.


[QUOTE=N8YX;665620]Modifying the TS-530 Rectifier Unit - Part 2



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[g1cpu]

I am writing to thank you guys for documenting these improvements. I stumbled on this article and then this forum yesterday. I am in the middle of breathing life back in to a TS-530, two TS-830S's and a TS-830M (as shown on my qrz page). The photographs say a thousand words and help me confidently to look where the action is. Although this article was last updated a couple of years ago, those like myself still find snippets of well documented suggestions like this very valuable. Thanks. Greg G1CPU

[N8YX]

I am writing to thank you guys for documenting these improvements. I stumbled on this article and then this forum yesterday. I am in the middle of breathing life back in to a TS-530, two TS-830S's and a TS-830M (as shown on my qrz page). The photographs say a thousand words and help me confidently to look where the action is. Although this article was last updated a couple of years ago, those like myself still find snippets of well documented suggestions like this very valuable. Thanks. Greg G1CPU

Greg,

Quite welcome. As I'd indicated earlier in thread I have a project -S that I'm going to convert to an -M and redesign the AM TX side of things in the process to get away from the (in)famous sideband+carrier approach that Kenwood so loves.

Be sure to post pics or details of what you run into with yours as you go.