#100 Kenwood TS-520 SE Series Repair Thread - Page 1
Forum section: electronics / rf-microwave

author: Radio Tech
author_rank: Frequent Contributor
timestamp: February 15, 2017, 02:35:15 am
content: In this thread we will cover the Kenwood TS-520 SE repair series.In this un-edited video we take our first look into this TS-520 SE. Can we bring this old rig back to life? Stay tuned aswe work through several unexpected problems together.If you have not seen the mail time video where this radio came in look for video 99.

author: xrunner
author_rank: Super Contributor
timestamp: February 15, 2017, 02:40:59 am
content: Looking forward to watching this in several sessions.

author: Radio Tech
author_rank: Frequent Contributor
timestamp: February 15, 2017, 02:57:33 am
content: Quote from: xrunner on February 15, 2017, 02:40:59 amGreat. It will be a lot of work. But it looks promising now.Will be quite a few videos on this series.

author: xrunner
author_rank: Super Contributor
timestamp: February 15, 2017, 03:50:36 am
content: Oh that switch - you're a braver man than I.

author: Radio Tech
author_rank: Frequent Contributor
timestamp: February 15, 2017, 01:08:55 pm
content: Quote from: xrunner on February 15, 2017, 03:50:36 amA lot of switches like that intimidate folks. Trust me, it is not difficult. Use schematic as a reference, take plenty of pictures, and draw it out on paper. This puts a mental picture in your head. Then take a deep breath and rip it out.

author: AF6LJ
author_rank: Unknown
timestamp: February 16, 2017, 04:51:53 am
content: I'm looking forward to watching it...I have my own little soap opera that has been playing out that is holding my progress on a project over on QRZ..The TS-520 should be fun.

author: Radio Tech
author_rank: Frequent Contributor
timestamp: February 16, 2017, 10:04:20 am
content: Quote from: AF6LJ on February 16, 2017, 04:51:53 amYep it is sort of a long video. An hour and twenty minutes. It was also fun to see this radio come to life which was hard to believe because all of the rust and corrosion on it. You have a new project going on? Posted on the ZED? If so I need to check that one out. I do not get over there much. I did post this video over there just because so many ask about these rigs.Hope you enjoy the video Sue.

author: AF6LJ
author_rank: Unknown
timestamp: February 16, 2017, 02:13:26 pm
content: Quote from: Radio Tech on February 16, 2017, 10:04:20 amI have taken over a project a friend has started....My personal soap opera has delayed progress on that project....I fell and lost my contact lens and should get a replacement in a couple of weeks .... I hope. Other than that...There is some test equipment repair coming which I will be doing over here, I think...After that.......A new Ham Radio related project is slated for later in the year.

author: KD0CAC John
author_rank: Frequent Contributor
timestamp: February 16, 2017, 02:48:39 pm
content: A couple yrs. ago , I found somewhere a wafer switch repair cabinet , this was a repair shop repair kit , is was used but most of the parts were still there .This great video made me sad - I chickened and did not buy ;(Now waiting for the next installment

author: voltz
author_rank: Frequent Contributor
timestamp: February 17, 2017, 08:14:02 pm
content: Another fine video Buddy. Yeah its so easy, take the switch out, clean it and then put it back. Simple huh.. 5 minute job - not! lol.Nice to see this process happening without too many edits, really gives an appreciation of the effort involved.Cheers.

author: German_EE
author_rank: Super Contributor
timestamp: February 18, 2017, 04:19:27 pm
content: I had to smile when you managed to locate a source for the switch spring, one of thoseYES !!moments.A good engineer never throws anything away on the principle that something will always come on useful at a future point in time. Granted, that point may be a few years, but I think that we all have junk boxes that we can raid now and again. My particular triumph was a solenoid controlled switch that I bought years ago 'because it looked interesting' and I sold it last year to someone building an automatic ATU for ten times the purchase price.There are various ways of dealing with complicated wiring around a switch. Apart from copious notes I have a box with ten different colors of tie-wrap in them, that helps sometimes when keeping wires in order. Just don't even think of working on this sort of stuff if you're color blindFinally, congratulations on video 100

author: Radio Tech
author_rank: Frequent Contributor
timestamp: February 20, 2017, 03:40:46 am
content: Quote from: AF6LJ on February 16, 2017, 02:13:26 pmHi Sue,Sorry got tied up lately. Hate to hear about you contact but I hope you are ok after the fall. That is never good at our age. Well at least mine lol. Sounds like you have a busy sked. Love to see the results of your repairs. Will be looking forward to them.

author: xrunner
author_rank: Super Contributor
timestamp: February 20, 2017, 03:43:45 am
content: Yea I watch the entire video! Very nice - are you going to re-align the thing? That would make an interesting watch as I do some of that here and would be interested in seeing your techniques and test equipment in action.

author: Radio Tech
author_rank: Frequent Contributor
timestamp: February 20, 2017, 03:45:25 am
content: Quote from: KD0CAC John on February 16, 2017, 02:48:39 pmDon't you hate it when you do things like that. I have done the same in the past. See something and hesitate on getting it. Next thing you know you find you need it and it is no longer available.Just finished editing the next video on this series. Will upload it tomorrow. Will be on the external and internal VFO.Thanks

author: Radio Tech
author_rank: Frequent Contributor
timestamp: February 20, 2017, 03:49:30 am
content: Quote from: voltz on February 17, 2017, 08:14:02 pmThanks, That switch repair was very intense and time consuming. Glad I do not have to do that every day. Decided to just let the camera run while working instead of editing it out.Thanks for watching. Part two will be out soon. About as long.

author: AF6LJ
author_rank: Unknown
timestamp: February 20, 2017, 04:24:36 am
content: Quote from: Radio Tech on February 20, 2017, 03:40:46 amNew project arrived on Friday there is a Heathkit SB-221 that is in need of some work.Long story but there is something wrong with the primary wiring...Then some minor items....The amp was a gift from a friend...He got himself a another amp after having problems with the 221..He was replacing the fan motor and the circuit breakers and something went wrong.....This is a project for later in the year.. When I get my lens I have to finish the HW-9 QRP radio that belongs to a friend. (it is over on QRZ..) Then I go into the Spectrum analyzer repair business. I most likely will start that thread over here. ....More to follow...This is going to be a busy year.

author: AF6LJ
author_rank: Unknown
timestamp: February 20, 2017, 04:27:20 am
content: Quote from: Radio Tech on February 20, 2017, 03:49:30 amI might have done it differently..If I could get the switch to clean the panel I would just disassemble it with the wires attached.Good work...I hate broken switches.

author: Radio Tech
author_rank: Frequent Contributor
timestamp: February 20, 2017, 10:12:48 am
content: Quote from: German_EE on February 18, 2017, 04:19:27 pmI tell you it was a real crowd pleaser when I ran across those replacement switch parts. I got lucky on that.Good deal on the solenoid switch. I am horrible about not letting things go that others would throw out. Just never know when you would need a part.Thank you my friend for your comment and congraz. Cannot believe I have reached 100 already.

author: Radio Tech
author_rank: Frequent Contributor
timestamp: February 20, 2017, 10:14:09 am
content: Quote from: xrunner on February 20, 2017, 03:43:45 amThanks. Yes I will be doing a video on alignment of this rig in the future. So much to do and part two is coming soon.

author: Radio Tech
author_rank: Frequent Contributor
timestamp: February 20, 2017, 05:22:58 pm
content: Quote from: AF6LJ on February 20, 2017, 04:27:20 amGood luck on that 221. I really hate those amps. Not sure why but never cared for the,. I do like the Drake L4B.Sounds like you indeed have a busy year planned out. I really wish I had time to do all the stuff I wanted to. I turn down so much work. I know just this past week end I told seven folks no on sending in repairs. just no time and I do have a back log.I agree with you on leaving the wires attached. But I try and keep the folks learning in mind. Since each wafer is tied to the other with jumpers you have to be really careful in taking it apart. When all the wires are removed I think it would be an easy repair, other than dealing with the wires.

author: Radio Tech
author_rank: Frequent Contributor
timestamp: February 20, 2017, 05:25:21 pm
content: The Kenwood TS-520 SE series Part 2 VFOIn this part two series we will examine the problems with both the internal and external VFO units.Both of these seem to have mechanical issues.

author: AF6LJ
author_rank: Unknown
timestamp: February 20, 2017, 08:04:02 pm
content: Quote from: Radio Tech on February 20, 2017, 05:22:58 pmThe SB-220 / 221 are built to a cost but well built for that cost.This makes my second amplifier in that line. I have an SB-220 I picked up for a decent price. that required some work. The link is here.....http://forums.qrz.com/index.php?threads/sb-220-find.372651/The person who built it ran it for a time then modified it for 160 meters. I didn't like the mod, it was not well executed, so I returned that section to stock and then proceeded to modify the amplifier myself.The power supply was upgraded, larger diodes, the whole high voltage board was rebuilt with better parts. filter caps were doubled giving 50MF at 3600V. A better plate choke was used . Step start inrush current limiting was added. There is more to be done, and this follow on project has been pushed back three years now.I wouldn't run this amplifier at full power on RTTY the transformer is only rated for 800VABut the larger caps in the power supply made a big improvement in dynamic regulation.Phase two will be to replace the T/R relay and bias circuit, Phase three is a new plate transformer that is rated for 1.5KVA. At that point it's not an SB-220 anymore.The SB-221 will get similar treatment...

author: Radio Tech
author_rank: Frequent Contributor
timestamp: February 26, 2017, 12:41:52 pm
content: Cool Sue. I will check out that link, Thank

author: Radio Tech
author_rank: Frequent Contributor
timestamp: February 26, 2017, 12:46:51 pm
content: Lets look at the AT-200 Antenna tuner