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Restoring a Kenwood TS-430S

The TX and RX are way down because of the cracked 1N60 glass diode. This diode switches the IF signal path through the crystal filters and with that diode open there will be almost no signal there.

Thanks for that info shockwave. I have not had time to get back on mine lately. So many other rigs in the shop along with other problems. May try and replace that diode this week end and see if that restores some things.
 
Went out in the shop when I got home tonight. Took the 430 down and finished up some solder joints, replaced that broken diode. All I had in stock was a 1N34A. So need to order some 1N60's. But the radio is singing like a charm.

Going to do a tune and align on it and make sure everything is up to spec.
 
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The TX and RX are way down because of the cracked 1N60 glass diode. This diode switches the IF signal path through the crystal filters and with that diode open there will be almost no signal there.

I wanted to quote this one more time.
First thanks again Shockwave for this info.
Second, I think this shows again the quality being lacked in the design Engineers of the time. Most of the time when we see components on the trace side of a board, there is either no room left on the component side, it was a decision after first production run. But to put a major component like D81 (1N60) on the back side of the board just blows me away. There was plenty of room on the top side. Does not appear that it needs to be where it is located to shorten the signal path.

Beats me, it is like they forgot:headbang
 
It's my pleasure to help out. You already knew the diode was bad. I just gave you the motivation to change it by letting you know at this point it would likely restore both the RX and TX. Kenwood placed parts like these under the board because they are sensitive to stray RF pickup from other circuits in the radio. Reducing lead length and / or placing them under the ground plane of the PC board accomplishes this.

I spent many years as a service tech for a Kenwood, Yaesu, and Icom authorized business. More Yaesu and Icom rigs came across the bench than Kenwood's. The one you have was probably used in a pickup truck or other rough mobile application during part of its life. Check for wear marks around the mobile mounting bracket screw holes. Any solder connections with weight, pressure, temperature change or one end vibrating while the other is fixed can develop cold joints.

The most common problem on these rigs was the bad wax in the PLL circuits becoming conductive with age. If you get all dots on the screen, start by scraping out as much wax as possible. Melting it out can cause it to run deeper inside things like RF transformers and that would be bad. Another common problem is the cable connectors on the boards can oxidize and become intermittent. Tapping them with a plastic rod can localize the troubled one. Clean them with good contact cleaner and check the solder connections for rings around the pins.
 
It's my pleasure to help out. You already knew the diode was bad. I just gave you the motivation to change it by letting you know at this point it would likely restore both the RX and TX. Kenwood placed parts like these under the board because they are sensitive to stray RF pickup from other circuits in the radio. Reducing lead length and / or placing them under the ground plane of the PC board accomplishes this.

I spent many years as a service tech for a Kenwood, Yaesu, and Icom authorized business. More Yaesu and Icom rigs came across the bench than Kenwood's. The one you have was probably used in a pickup truck or other rough mobile application during part of its life. Check for wear marks around the mobile mounting bracket screw holes. Any solder connections with weight, pressure, temperature change or one end vibrating while the other is fixed can develop cold joints.

The most common problem on these rigs was the bad wax in the PLL circuits becoming conductive with age. If you get all dots on the screen, start by scraping out as much wax as possible. Melting it out can cause it to run deeper inside things like RF transformers and that would be bad. Another common problem is the cable connectors on the boards can oxidize and become intermittent. Tapping them with a plastic rod can localize the troubled one. Clean them with good contact cleaner and check the solder connections for rings around the pins.

Thats good info. Thanks.
I have spent quite a few hours repairing cracked solder joints on this rib. No evidence that it was used mobile though. looks like a bracket was never installed on it.

When I first got therig it had not display. So was looking at the PLL issues with them. And I agree about not heating the wax. Good tip to share.

I was a service tech for EF Johnson and GE LMR service for quite some time. Learned a lot back then so rolled that over into ham radio repair.

Was going to do a YouTube video on this rig but never got around to it. maybe the next time it quits I will. noticed I said the next time :tongue:
 
I know this is an old thread but will a voltage regulator from a ts440 work in a ts430 or are they 2 different animals
 
deadzombie.gif
 
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In all fairness both members are still here and active .
The regulators in question are three terminal positive regulators in a TO220 case. Really no point in salvaging a $1 part . just get one from ...

Okay , not an answer to your question. Yes the regulators are interchangeable with one caveat. Observe the pin out of the regulators carefully. There can be surprises.
 
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In all fairness both members are still here and active .
The regulators in question are three terminal positive regulators in a TO220 case. Really no point in salvaging a $1 part . just get one from ...
.
Just get one from where, I’ve looked but can’t find one?
 
ROFLM*O!!!!!
It appears that way.
To be honest....I have to say this.
By doing a bit of research from the era my thoughts are this.
Looks like Kenwood was having a bit of quality control issues during this time. This radio is early 80's vintage. I think they were trying to compete with other manufacturers out there and they lacked quality. Now we know that the 520 and 830s were rock solid! Were well built radios.

I also know they had used some strange solder in their wave flow operation. Man this stuff is hard and even todays rosin core will not stick to it. I have to remove the old solder and apply new. The two will not mix together. Perhaps it has a very high tin content. Beats me.

I just removed the IF board again for further inspection. And what I am finding is terrible.
Everywhere I look there are cracked solder joints. With some leads not even making contact with the board pads.

index.php


Another thing that leads me to think of Quality issues is the amount of “jumpers and bodged circuits. Everywhere you look on the board is these added circuits to the foil side of the boards. It is like the design engineers had no idea what they were trying to accomplish. Now dont get me wrong. I love these old radios.........
But just look at the back of the IF board.


index.php


Looks like I am going to invest in another camera with a macro lens. And maybe a good quality USB cam.

I purchased a 430 some years ago for next to nothing it cost more to ship it than I paid for it. I knew going in that the 430's had serious solder issues. I didn't even bother turning it on when I got I just disassembled it and did what you are doing. I put it back together and never experienced an issue with it and used it on the repair bench for 2 years without a problem. Good radios but yes! they had a bad reputation I must have repaired 30 or more of these all with the same kind of issues.
 
Might be a zombie thread but it contains some good info.
I have my fun but help where I can.The TS-430 is well known for its construction and solder issues.
The "Help" link below fairly completely describes the "via" issue. I haven't seen a TS-430 yet that didn't need extensive solder rework.

When working they are a capable radio for that era. Sure there are better now but if it's what you have, make it work!

https://www.qsl.net/wb4kdi/Kenwood/TS-430S/TS-430_HELP.html

http://g3ynh.info/commercial/TS430.html
 

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I'm just starting on a TS-430S which the PLL is unlocked. Only 1 digit shows on the display. There are ALOT of solder joints to reflow IF thats required- sounds like it may be sooner or later. Am checking voltages on IC5 of control board and IC1 of RF board and have noted discrepancies with service manual diagram. The voltage regulators and caps around them sound a common issue and cheap to replace so considering doing these. I haven't worked on a radio this "new" before - I'm more likely to be in a 520S or 101E!
 
Hello, sorry to wake this old thread. I have an output issue on my 430 where I get no output. I tested final transistor vias and removed and tested the output transistors as well. Are there other common failure points on final board. It receives great BTW. No output on any bands.. thanks so much!!
 

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