Kenwood TS-520 Restoration Project 1

The restoration of the Kenwoold TS-520 begins with the replacement of the high voltage caps. Just the beginning of a long project. 73, Tom, K2BEW

[@AMStationEngineer]

At 4:40, I really like those capacitor adapters, nice quality, and great repair-mod on their replacement, btw! I've seen that "bleeder-filter" arrangement on mostly higher-end rigs, and this Kenwood is no exception. I believe the theory behind that arrangement is that it is believed to enhance stability in hybrid circuitry. When completed, you will have a gem of a rig!! 73's, Tim

[@KB5PQL]

I recapped my TS-520SE a couple of years ago. It was a fun job. Not hard to do just a lot of caps! :)

[@RestoreOldRadios]

Nice job. I look forward to the next video in this series. Don

[@TheArtofEngineering]

Did the TS520 fly??? Part one was7 yrs ago...The suspense is killing me. The reason I ask is mine is presently on my shack floor in pieces...was working this arvo then POP!!! no output power. Tubes all glow....receive works.....but no output pwr! The HV Caps look bulged.....Should I bother?

[@Backtothefutureradios]

Is there other videos in-this series? I am beginning the recapping of my 520….Thanks-Larry WA4PJP

[@robertarchuletta2498]

If you have the "positive rail" going to ground then you have a problem. The positive side of one cap should be going to the + of the hv rectifier board. The "center tap" as you are calling it goes to one side of the hv winding. This is where one + and one - of the caps are connected. The - of the other cap should be going to ground.

[@johndecicco9908]

i just picked me up one of these TS 520s and the radio works greate i would like clean up the cosmetics of the unit, do you think theres any chance of me damageing any of the inside componints by removeing the case for painting if im real careful

[@kevindooley9371]

Great video. I picked up one of these on ebay recently very cheap and trying to put it into service. The first thing I notice is that when I rotate the main tuner knob, the dial scale and subdial do not move. Only the large center knob rotates, nothing else. Could that be a mechanical problem vs electrically related? (gear not meshing or drive belt or something) I'm wondering if the two dials should move in sync with the main knob, even when the set is off, correct?

[@kevindooley9371]

To answer my own question - yes. The outer tuning dial and sub-dial (behind the glass) should all move when the tuning knob is turned, whether powered on or off. I removed the VFO and found that the sub-dial was getting obstructed by a screw on the front frame behind the faceplate. I substituted a shorter screw and the problem went away! All tuning dials now turn simultaneously!

[@warplanner8852]

This may have been covered in the video but the two caps are in series.

[@gbennett58]

Please let me know where you got the schematic for this radio. The ones I got on the internet are very hard to read. - Geoff KE0BNX

[@tommybewick]

geochaben You can get the owners manuals in PDF that has the schematic in pretty good resolution here; www.wb4hfn.com/KENWOOD/Kenwood-Articles.htm ,although I have the original owners manual with it I don’t have a way to scan it. 73Tom,k3bew

[@gbennett58]

Thanks.

[@billvet6]

Nice job! Looking forward to seeing your progress. I have thought I would like to try a project myself. I am sure I will learn a lot here. [I know nothing!] 73 Bill AB9QU

[@michaelpfister8953]

Bill Carter AB9QU

[@one4gimp]

Nice Showing your mistake helps. I hope to see the final alignment procedure at the end. Tom K9ASE

[@robertarchuletta2498]

At first glance of the hv circuit it looks a bit confusing. But the hv board is a half wave rectifier circuit. Just imagine one capacitor being charged from one half of the cycle and the other cap being charged from the other half of the cycle. Each capacitor has exact half of the 800 vdc charge. Between ground and the positive rail you have 800 vdc.

[@danieladams2824]

I need frequency drift fixed on my ts 530s & ts 130s my call KB8WTA l'm good on qrz.

[@tommybewick]

I would suggest joining the Kenwood Hibred reflector on Yahoo groups, groups.yahoo.com/neo/groups/TS-520_820_530_830/info, you'll get lots of help from experts there. I honestly don't know enough about these to know how to fix frequency drift, thanks for stopping by. 73,Tom

[@TheArtofEngineering]

Sorry....my name is George VK2AOE