116x Rectifier light show

[thirtiesradio]

A bucking transformer is a good idea on these sets. I have one in my 16B and have used it for many,many hours with no problems. I also added a CL-90 thermistor on one side of the AC line to prevent current surges at start up. Getting the AC line voltage down to around 105-110 VAC is a good idea and will not change the performance of the set at all. Check your voltages at startup on the capacitor that is having problems with the rectifier installed.

[Glenn Roberts]

Ron Ramirez Wrote:In your 116, with a higher input B+ voltage (especailly if you were to run it at full line voltage), you may have to switch to a 500 volt electrolytic. There is someone who sells these much cheaper than anyone else I have found so far on the Web - Studio Electronics.

http://www.studioelectronics.biz/sunshop...ail&p=1729

Wow..Great find Ron!. The shipping is a little high, I checked on 20 Caps, it was $14.40, Just Radios is $7.90. I think that is a flat rate too, he does have the 500V and higher rated caps.

Glenn

[codefox1]

You could also wire two 20 mf in series and you would then end up with a 10 mf at twice the voltage. Some like to add bleeder resistors, say 330 K across each cap when they wire them this way. This is done a lot in guitar and audio amps. Jameco is also a good source, and it's pretty easy to find enough stuff you can't live without to take the sting out of shipping.

[garyh1]

I took your advice and ordered 500v caps. I played the radio for awhile last night through a variac set at 108v with no issues. I am hoping the only issue is high line voltage. Where would be a good place buy the bucking transformer I would need to construct a set up like yours. Gary

[TA Forbes]

In my case (AK 92) it turned out to be a speaker wire making intermittant contact. At first I thought the 2K ohm coil was open, but it was the wire just above the jack. This would cause max B+ being felt at the - side of the cap that was failing.

Rewired the entire jack, as there were 2 more wires approaching the condition of the bad one, and am listening to the race on the AK as I write this.

[thirtiesradio]

TA Forbes Wrote:In my case (AK 92) it turned out to be a speaker wire making intermittant contact. At first I thought the 2K ohm coil was open, but it was the wire just above the jack. This would cause max B+ being felt at the - side of the cap that was failing.

Rewired the entire jack, as there were 2 more wires approaching the condition of the bad one, and am listening to the race on the AK as I write this.

Yes.... the AK sets have that rubber coated wiring that gets brittle. I have a 206 and 447 that I had to rewire much of the wiring.
I've found excessive draws that cause filter cap problems. Hopefully by using the higher rated cap and a bucking transformer it will solve the problem he is having..but if two capacitors went south there may be a draw somewhere. Both my 16B and 116 have been fine with 450V rated capacitors.....even when they were running on normal line voltages.