Kenwood TS-430S Relay Repair - Strange Way to Fix a Radio 

Love my TS-430S. Had to change the relays though, but the receiver is very good considering it's age.

I used to have a Kenwood TS-430S but gave it away when I got my new Yaesu 991a. It was a good radio for the past 4 years. ALC is Automatic Limit Control which you set with your mic and the gain knob. Key the transmitter and watch meter and keep it out of the red with the mic gain. Cheers & 73 from W Rusty Lane K9POW in eastern Tennessee

I have a TS430S that I started using last year, after putting up a trap dipole and modifying a heavy linear supply that was originally in a server rack. The TS430S worked well for awhile. I worked a couple of Japan stations and some East coast stations. Lately I noticed the reception drop down a lot after I transmit. I disagree with your statement that there are a lot of relays inside the TS430S. There are 14 relays on the transmit filter PCB. However they have nothing to do with receive sensitivity. I looked at the schematics for the RF Unit in this radio and between the antenna and the preselector circuits there is one relay, RL1. In the receive circuit, (RF Unit) the ten preselector circuits all have PIN diodes and not relays. If the radio exhibits dropouts, as you demonstrated, RL1 needs to be replaced. It is not easy to do since it is soldered in. The RF Unit is on the bottom of the radio. The relay PN in the TS430S Service Manual is (Fujitsu) FBR211A The relay in my radio is an OMRON G2E 187P-M Both are SPDT 6 pin 12 V coil relays, so there could be many other replacements. The contact heating method you describe as a temporary fix does not do anything. The DC path to ground from the antenna connector when the TS430S is in receive mode is through a PIN diode and a 47k ohm resistor in each preselected circuit. There is the danger of exceeding The current rating of the PIN diode by doing this procedure. The original and only relay on the RF Unit board had Gold plated contacts. Over time and due to static discharge, the contacts become pitted. You can't fix that. Watching your video it looks like there are still reception fluctuations as you go up in frequency.. Each time you cross into another frequency band, the radio switches to another preselector, and so RL1 toggles and the attenuation changes. My theory is it does that to protect the PIN diodes from any static coming from the antenna. You should get a lot of noise on the low bands and gradually less as you go up in frequency. If it jumps around, that is not atmospherics. Its your radio. There might be other reasons why the TS430S's receive sensitivity drops suddenly. I have ordered the OEM replacement for RL1 and will replace it ASAP. I hope that will fix the problem.

Love your channel Jim! I must say, after decades being into shortwave radio and repairing them, at 8:54 you say that you really don't know what Processor and ALC are in a radio? Your curiosity has never in decades been piqued to discover how an amateur radio works? I say this as someone who doesn't have 1/4 of your repair knowledge and yet since 1992 I found a love for HF radio and have learned every year since.

Kindly advise: I extracted the output filter board of a TS-430S to work on it. Issues: 1. Intermittent low rx (probably "dirty" relays). It appears they are all sealed (except the tx/tx relay). I tried using a "wetting voltage" as described in a Kenwood service bulletin, but there is still intermittent loss of rx, especially on 10m. 2. One of the inductors (L41) is shorted. 3. How do you test a diac (D18)? (It reads short circuit in both directions.) Apparently it is for overload/surge protection. 4. The S meter reads extremely low. I failed to recalibrate S9 (even with the trim at maximum, it doesn't reach 9).

This brings back memories. I had the Kenwood TS-530 S.

Has anyone tried creating and installing the contact maintenance circuit as described in the same service bulletin (SB-902), which is intended to mildly clean the contacts every time bands are switched? If so, what would you recommend to use instead of the now discontinued L33-0259-05 choke?

Crazy !

How do you push amps , i thought amps were drawn by a device ? Cheers .

Hey I am buying a TS-430s Kenwood Radio would you please go over and fix anything wrong with it can you do that or is that too much to ask? Thank you.

Nice, Milton Lords old trick

This hf radio is well over 30 years old. Replace the relays, there cheap enough. I’m not going to juice my antenna connector with 500 milliamperes. It cost me 15 dollars to replace all the relays

How many volts do you use.????

So, what happened with the motorboater radio, you throw the towel ?

I thought you had to use a resister?

Looks like you only used 3 volts, not 13.8!

i've tried this with my PlayStation 5, all I got was smoke... Smoke and flames everywhere...!!!

the sound of this video is bad quality like 32 kbps or 24 kbps

Never seen (or heard of) that fix before.N9zxr