[MRCA] Hammerlund BC779/ super pro 400 mods documentation

[J Mcvey]

Thanks to all who responded. 
It turns out that the bulk of the mods appear to follow the changes recommended in the April 1961 CQ mag. ( special thanks to  Rich McClung who had this and many other mod docs!)

This radio has the original power supply, so things got ugly when the guy tried to fudge the second 150V isolated buss from the 225V line
There are  extra resistors and a 180 uf cap , etc. very strange...All of that is getting yanked and replaced with a proper dropping resistor and 150V, 5W zener. (1n5383B) DONE!

I suspect that the IF may have oscillated with that configuration because some of the values were changed from the CQ version. In fact I'm not sure that this stuff ever worked. I'll find out when I get this all re-caped and modified to something reasonable.


   On Saturday, April 16, 2022, 09:25:42 PM EDT, Mike Feher <n4fs at eozinc.com> wrote:  
 
 #yiv4948416704 #yiv4948416704 -- _filtered {} _filtered {} _filtered {} _filtered {}#yiv4948416704 #yiv4948416704 p.yiv4948416704MsoNormal, #yiv4948416704 li.yiv4948416704MsoNormal, #yiv4948416704 div.yiv4948416704MsoNormal {margin:0in;font-size:11.0pt;font-family:sans-serif;}#yiv4948416704 a:link, #yiv4948416704 span.yiv4948416704MsoHyperlink {color:blue;text-decoration:underline;}#yiv4948416704 pre {margin:0in;margin-bottom:.0001pt;font-size:10.0pt;}#yiv4948416704 span.yiv4948416704HTMLPreformattedChar {font-family:Consolas;}#yiv4948416704 span.yiv4948416704EmailStyle20 {font-family:sans-serif;color:windowtext;}#yiv4948416704 .yiv4948416704MsoChpDefault {font-size:10.0pt;} _filtered {}#yiv4948416704 div.yiv4948416704WordSection1 {}#yiv4948416704 
I have an entire collection of the smaller, original size CQ magazines. If you can tell me what issue you need info from. 73 – Mike 

  

Mike B. Feher, N4FS

89 Arnold Blvd.

Howell NJ 07731

848-245-9115

  

From: mrca-bounces at mailman.qth.net <mrca-bounces at mailman.qth.net> On Behalf Of Al Klase
Sent: Saturday, April 16, 2022 3:48 PM
To: mrca at mailman.qth.net
Subject: Re: [MRCA] Hammerlund BC779/ super pro 400 mods documentation

  

Hi Jim,

I just discovered there is an online CQ archive:     But, they want 5 bucks and day/ 10 bucks a month to access anything but the TOC's.   See:  https://hamcall.net/cqcgi/?res=l&yr=1961&mo=04




73,
Al

On 4/16/2022 3:12 PM, J Mcvey via MRCA wrote:


I have this hacked BC779 here which had the low langes 100-200 ans 200-400 modified to 160 meters and 10 meters respectively.  I don't know how well this works as I am in the midst of re-capping the radio before i fire it up.

  

However there are many other mods done to this radio, including the addition of an OA2 regulator and seemingly a lot of extra circuitry associated with it.

  

I understand there was an article in the April 1961 edition of CQ mag that described many of these  mods.

I want to compile  as much documentation about what was done , so I can decide whether to keep the mods or not.

It is also helpful to have the schematics for them to keep with the radio manual for future reference. There was no documentation from the previous owner.

  

Does anybody have a scan of the CQ article or any other info on BC779 mods?

  

Thanks, 

Jim , AC2EU

  

  




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-- Al Klase - N3FRQJersey City, NJhttp://www.skywaves.ar88.net______________________________________________________________
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