De-mothballing Tranceivers (TS820, IC240)

[jpedley]

Having recently returned to Uk I have uncovered all my old amateur radio equipment, boxed up since 1985. The main items are

TS820 Transceiver (hardly used!)
IC240 2m FM transceiver
2m linear amplifier
10m-2m transverter

I spoke to Lowe electronics from whom I originally bought the Kenwood TS820 (it's still in their box!) and they advised me to run up the voltage over a period of time with a variac so I dont blow the electrolytics. Alternatively to run from 110V supply over short periods.

Would the forum want to comment on the approach, similar experiences. Can I expect the stuff to work? It's all been in a dry loft all this time.

Cheers

Jules, G4CKL

[dsergeant]

Maybe as a precaution yes, but I don't expect you will have any problems. Capacitors of that age do not normally suffer from the catastrophic problems of those in vintage equipment. Yes it will all work just the day it was put in the box.

Dave

[M0AFJ, Tim]

Hi Jules, no you should not have any problems, however you may find that operating standards have changed in 21 years!!
73
Tim M0AFJ

[Station X]

At the risk of throwing a spanner in the works I've had capacitors fail in equipment of this age. Not electrolytics though, but tantalums. In my case a failed tant in a 70cms mobile transceiver put a full short across the 12 volt power line and burnt out the PCB track. The fault was simple enough, but repair was difficult, because the cap was inside a screening can with soldered screens.

I also had an electrolytic in a car radio leak electrolyte and dissolve the PCB track beneath it. This was not visible until the cap was removed.

A visual inspection of the inside of the sets might be in order, as might keeping them in a warm place for a day or two to drive out 20 years of moisture.

I'm not familiar with the equipment described, but if it's mains powered I'd be inclined to use a 100 watt light bulb in series with the mains. This has the advantage of limiting the current. It would be a shame to destroy an irreplaceable mains transformer for want of this simple precaution. Even "modern" electrolytics can need reforming.

[jpedley]

Originally Posted by M0AFJ

Hi Jules, no you should not have any problems, however you may find that operating standards have changed in 21 years!!
73
Tim M0AFJ

I would love to hear more. What's the calling channel on 2m? I am feeling like I am in a "back to the future" scenario already

[jpedley]

Originally Posted by Station X

At the risk of throwing a spanner in the works I've had capacitors fail in equipment of this age. Not electrolytics though, but tantalums. In my case a failed tant in a 70cms mobile transceiver put a full short across the 12 volt power line and burnt out the PCB track. The fault was simple enough, but repair was difficult, because the cap was inside a screening can with soldered screens.

Thanks, I will bear this in mind. The TS820 is a multiband HF tranceiver, but probably one of the last to use tubes in the final (6LQ6?)

Yes, a minor fault in equipment of this age could be disastrous. So difficult to get the parts. In my heyday with ex-admiralty receivers like the B40 you could do your own repair jobs.

Regards

[M0AFJ, Tim]

Originally Posted by jpedley

I would love to hear more. What's the calling channel on 2m? I am feeling like I am in a "back to the future" scenario already

Hi, well it is still 145.5 but activity is very poor, the ex cBers congregate on the repeaters, very little simplex activity on either FM or SSB.
I could go on but will definatly incurr the wrath of the moderators!!

Just that when we were first licenced (me 1972) aspiring amateurs generally served an apprenticship as a listener....., not now though!!, jump in with both feet and large mouths...

BR
Tim M0AFJ, x G8GGP

[Valleyjinker]

Originally Posted by dsergeant

Maybe as a precaution yes, but I don't expect you will have any problems. Capacitors of that age do not normally suffer from the catastrophic problems of those in vintage equipment. Yes it will all work just the day it was put in the box.

Dave

I accept the truth of that but the situation in the TS520/530/820/830 is that the capacitors are wired in series with fairly high value ballancing resistors, so if one cap is basically OK but a bit reluctant to come up to voltage, then the other one "gets it".