Kenwood TS-520 Overhaul

[KG6TJU]

I have a Kenwood TS-520 that I am fixing up. It had been sitting on a shelf for 20 years so things are a bit clubby. One strange thing is the RIT switch seems to be a bit loose, and when I fiddle with it (not actuating the switch, just nudging it a bit) the VFO and RIT lights will flicker and my reception goes all to hell.

 Any tip or pointers on working this thing over? It will be my first of several rebuilds I want to do, but this one is to be my main HF rig for now as it is in the best condition.

 I also have an R-390A and a Viking II I will be working over in the future.

 any help would be much appreciated.

[KL7OF]

TS 520 does not have an AM mode....I have one that was my daughter"s novice rig...The speech processer makes you sound LOUD (if not a little distorted)on SSB.....Never had the front panel off...You may have to drop the panel to fix yours.....Good Luck

[wb1ead]

Hans I've only had one of those so far on the workbench..the problem was an intermittent band switch..without complete removal/changeover of the switch it wasn't repairable..customer said no($$$) and back it went..however I do HAVE the TS-520 service manual here in case ya run into sumptin ya can't figure out..the service manual I think can be downloaded if ya know where to look..but then agn not 100% sure of that..so taking my non-repair here..it appears that switches in general on this one may be troublesome..if possible try to remove and mark the wires and once out ya might see if repairable on the RIT switch..you may or may not have to remove front panel which can be a pain in the keister but doable......gud luk   73 de DAVE

[Ed/KB1HYS]

I've got a TS-520 (no S) nice rig, good CW and SSB rig. It can be modded for AM fairly straight forward, but it will be a Transmit only mod.

One thing to watch out for are the couplings(?) on the band switch shaft, they've been known to break and it's a bit tricky to get into repair it since the shaft is in a few sections through the band switching circuitry.

As far as the RIT switch, never had a problem on mine, but IIRC if its loose it could be shorting back there when you move it. It's been a while since I dug into mine but I think it was tight in there. 

[KA2QFX]

I've worked on quite a few 520s over some years. Just re-capped one for a customer (what a PITA). So if you run into some oddities that the service manual can't answer I'll try to help.

They do have a tendency to develop noisy pots and switches, using them helps. The RIT switch will require a fair amount of dismantling to fix correctly but will likely clean up OK with a little electronics cleaner and some TLC.  Don't use anything that leaves a residue. Long term that can be a problem.  

The plastic shaft shaft couplings are common failure as mentioned earlier.  Straight couplings are usable but the insulated self aligning couplings are available from after market suppliers. http://www.sdp-si.com/eStore/CoverPg/couplings.htm is one source. There are others but I just changed laptops and haven't moved all my bookmarks yet. I'll post more info when I get to that... soon.  

Good luck with it.

Mark