[Heathkit] IM-25 "SS VTVM" Power Supply Mod?

[Ron]

I used the appended circuit in my IM-25 to great effect. It is fed by the two D cells 
that power the Ohm function (doesn't affect their life) and does not require the other 
cells. The circuit may be installed to the space vacated by the mercury cell holder. 

https://www.dropbox.com/sh/gituxwqvcex0jpd/AABIn86fF6tHND68XB__CCZza?dl=0
-- Ron
 


 
      From: jack m <oldvette at hotmail.com>
 To: "heathkit at mailman.qth.net" <heathkit at mailman.qth.net> 
 Sent: Friday, December 25, 2015 1:54 PM
 Subject: [Heathkit] IM-25 "SS VTVM" Power Supply Mod?
   
(This query has also been posted on QRZ-Boatanchors Tech Forum.}
 
I am attempting to get my vintage IM-25 solid state ssvm working again.  The unobtanum mercury battery is spent, and I am tired of replacing the 14 C-cells due to cost (which is the main reason I retired it 15 years ago).  I have not been able to locate a new 1.35 v battery so far, even at the camera stores or Batteries Plus (& Bulbs).

 Does anyone know of a power supply circuit or mod for the voltages - especially the 1.35 v ohm circuit - before I start trying to reinvent the wheel?  I do not need the battery or portable capability for this unit.

 Thanks.

 Jack
 W3RU  
                         
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