[Hallicrafters] SR-150 Low output

[Jim Liles]

Hi Burt,

Couple of suggestions.  

Take a moment and review the papers that Walt Cates WD0GOF wrote regarding the SR-150.  One is meant to bring an SR-150 to factory specs and does so in a very easy to follow format.  You should be able to do the job with common ham shack instruments.  Several have used Walt's paper with 100% success.  Walt has published the same paper for the SR-400 with the same success.  I don’t believe you will find technical documentation anywhere else as well written.

The very first thing that I would do is replace relay K1 and K2.  The Hallicrafters  purchasing guys found 2000 of those relays that cost only .25 cents and 300 Kellogg's Wheaties box tops.  They have a phenolic plate that the contacts are mounted on which warps, allowing all three contacts to come together.  Walt has provided a paper that has part numbers for new relays and the installation procedure.  Replace the relays first; they’re responsible for the majority of anomalies in that radio.

Kindest regards 
Jim K9AXN    

-----Original Message----- 
From: K4PRF - Burton Pratt 
Sent: Friday, February 27, 2015 1:00 PM 
To: hallicrafters at mailman.qth.net 
Subject: [Hallicrafters] SR-150 Low output 

I am the original owner of this SR-150 transceiver and just hate the 
idea of putting it out to pasture.  It just will not make power in 
either SSB or CW.  If I unbalance the carrier it will make power which 
leads me to believe that the final section is functioning properly.  All 
the voltages and resistances are in the park.  Tubes have been checked 
and substituted.  If I understand the theory of operation correctly CW 
output is controlled by bias.  If the carrier is being cut off by a bias 
problem would that also kill the SSB output?  Any help will be 
appreciated.  I would love to get this old Hallicrafter back in action. 

73,

Burt, K4PRF

______________________________________________________________
Hallicrafters mailing list
Home: http://mailman.qth.net/mailman/listinfo/hallicrafters
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Hallicrafters at mailman.qth.net

List Administrator: Duane Fischer, W8DBF
** For Assistance: dfischer at usol.com **


This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html