[Hammarlund] BC-779 Latest Update

[Bob Young]

I just bought a nice refurbished HP 410B VTMM complete with probes in 
excellent condition for 110.00 plus shipping, this seller usually has them 
available, packs well, double boxes everything and they are great for 
boatanchors, if anyone wants to know the seller please contact me directly.
Here also a couple: 300066642153  230074770639  I have no connection with 
these sellers, mine was bought was a company who regularly refurbishes these 
and other classic boatanchor equipment

Bob Young
Millbury, Ma


>From: "Greg Mijal" <bluebirdtele at earthlink.net>
>Reply-To: Greg Mijal <bluebirdtele at earthlink.net>
>To: "Carole White-Connor" <carolew at bellatlantic.net>
>CC: hammarlund at mailman.qth.net, milsurplus at mailman.qth.net
>Subject: Re: [Hammarlund] BC-779 Latest Update
>Date: Sun, 7 Jan 2007 22:46:05 -0700
>
>Sounds like you are looking at voltages with a DMM, everything reads higher 
>than your old book spec's based on a 20k ohm multimeter or whatever.
>The -12.0 volt comment does not compute here.  Grid voltages with avc 
>action impressed read not more than a couple of minus volts on my stuff and 
>the voltage fluctuates as the signal strength changes.
>The only way I have been successful in troubleshooting avc problems is 
>tracing out the basic avc system then disconnecting the avc control voltage 
>grid by grid until the failed stage is found and I always use an 
>oscilloscope to do this with.  It's time consuming cleaning up the mess 
>later but it works here.
>Hang in there baby!
>Greg
>WA7LYO
>in sunny Feenix
>----- Original Message ----- From: "Carole White-Connor" 
><carolew at bellatlantic.net>
>Cc: <hammarlund at mailman.qth.net>; <milsurplus at mailman.qth.net>
>Sent: Sunday, January 07, 2007 7:07 PM
>Subject: Re: [Hammarlund] BC-779 Latest Update
>
>
>>Not much progress on the AVC problem. I'm giving the voltages. Perhaps 
>>this
>>will give someone an idea of the problem.
>>
>>AVC Rectifier (6H6)
>>
>>In Manual and in AVC, the cathode voltages are -3.2.  That's what the 
>>manual
>>specifies.
>>
>>In Manual, the plate voltages are -3.5. The manual says they should be 
>>-3.2.
>>In AVC, the plate voltages are -12.0. (The manual specifies only voltages 
>>in
>>Manual mode)
>>
>>AVC Amp (6SK7)
>>
>>In Manual and in AVC, the plate voltage is +270 and the screen is +140. 
>>(The
>>manual says they should be 240 and 110).
>>
>>In the Manual, the input grid is -3.2. The manual specifies -1.5V.  In 
>>AVC, it
>>is -12.(The manual specifies only voltages in Manual mode).
>>
>>In Manual, it actually is starting to sound like a Super Pro. Replacement 
>>of
>>the out-of-spec resistors and the caps has made a difference. I just 
>>pulled
>>C-34 out of the T-1 can. It's a Micramold and was leaking like most of 
>>them
>>do. It was a pain to get to but worth the effort.
>>
>>As always, thanks for your help. Any insights would be gratefully 
>>appreciated.
>>
>>
>>
>>Joe Connor
>>_______________________________________________
>>List Administrator: Duane Fischer W8DBF
>>** For Assistance: dfischer at usol.com **
>>----
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>
>_______________________________________________
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>** For Assistance: dfischer at usol.com **
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