[MAMS] Sad Note with 222 AM6155 AMP

[Dr. Gerald N. Johnson]

I've used that more than once in the past 57 years. Works every time and 
uses commonly available parts.

I just left the Fair Radio site, they do have a complete bias supply for 
$40.

73, Jerry, K0CQ

On 12/23/2012 7:34 PM, MARK K8MD wrote:
> I never thought of that. The tube I'm using is a 4CX400 and I'll have to
> look for Transformer around.in my collection of AMP parts Thanks. Mark, K8MD
>
> --- On *Sun, 12/23/12, Dr. Gerald N. Johnson /<geraldj at netins.net>/* wrote:
>
>
>     From: Dr. Gerald N. Johnson <geraldj at netins.net>
>     Subject: Re: [MAMS] Sad Note with 222 AM6155 AMP
>     To: mams at mailman.qth.net
>     Date: Sunday, December 23, 2012, 9:31 PM
>
>     It might be easier to find a small filament transformer than an
>     original. Didn't like 240 volts on the 120 volt primary? Usually
>     takes about 35 volts operating bias, more for blocking and shut
>     down. Connecting a small 6.3 filament transformer to the tube heater
>     transformer, low voltage winding to the heater circuit makes a
>     simple 120 volt AC isolation transformer. If you need only 50 volts
>     AC use a 12.6 volt filament transformer. Need not have significant
>     power capability for bias circuits usually.
>
>     In times past, Fair Radio has had AM6155 parts.
>
>     73, Jerry, K0CQ
>
>     On 12/23/2012 7:22 PM, MARK K8MD wrote:
>      > Today i decided to move Am6155 222 to 240 VAC after proper
>     jumping of amp and changing connector for VAC. I turned amp on and a
>     fuse blew. I found out previous person who tried to run amp had a 3A
>     fuse instead of 15A. Replaced and still would not run, no blower
>     noise. After an hour of checking, and checking. I tried to get it to
>     go comparing it to my 432 AM6155 and heard blower turn on for a
>     second and smoke came blowing out of amp.
>      >
>      > Upon pulling the grid bias section say that the transformer
>     smoked and burned pretty good. What Luck. These amps are getting
>     rare. I'm going have to find someone parting out a unit. I think
>     I'll drag out old amp and replace tube socket on pair of 4CX250's
>     and see if that will run. I still have supply that never smoked for
>     the 15 years I used for the 4CX250's.. If anyone knows of someone
>     parting out AM6155 let me know . Thanks Mark, K8MD
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