Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: When is a 75A1 too far gone to be brought back to life?  (Read 2105 times)
K1YTG
Member

Posts: 208




Ignore
« on: September 02, 2012, 10:30:53 PM »

I recently bought a good looking 75A-1 and was told it was in bad shape internally.  Nice panel and case though and all there. 
I have gone through the power supply, audio, Bfo, second mixer, dial and tuning osc, and these work after many hours of effort.
But the 1st If chain is in terrible shape from mouse droppings and urine.  I don't know how to get at the components and the effort seems too great. 
Perhaps I should give up at this point.  I can get another radio easier than getting this one going.
Another problem.  The input coil from the antenna terminals is fried, that is overheated and partially melted.  Rewinding it in a fashion that would work as far as the tuning and tracking with the slug might not be possible.  So even if I make the big effort to dis-assemble the variable IF and replace all the corroded trimmer caps and free up the slugs,  it still might never work well again. 
Part of me wants to prove that I can do this.  And it is hard to let it go. 
So I am asking for opinions on saving the radio at any cost or declaring it a parts rig.
Thanks, Norm
Logged
AC5UP
Member

Posts: 3869




Ignore
« Reply #1 on: September 03, 2012, 01:52:09 AM »

There is no good answer to this as it's a judgement call based on the condition of the specific piece, the cost and availability of replacement parts, skill of the rebuilder, and the expense in both time & money someone is willing to put into the project.

A few months back there was a link to a blog where someone restored an old Philco console radio that I'd have never considered as a viable rebuild candidate, but the results were nothing short of miraculous. Person doing the work had the time, tools and patience to make it look like new again. It is possible to restore a badly neglected piece and the question becomes whether it's worth it to the restorer.

Previous owner elected not to invest in that particular radio and sold it as you found it. There could be some very good reasons for that decision which might relate more to the person than the radio, or not. Now it's your turn to hold it for a while against the day when you score a parts rig or use it as a parts rig. As for "restoring it at any cost", the value of old Collins gear has risen remarkably over the past decade and it's easy to assume this will continue.

I say it won't, and for two reasons:

Gen-X'ers are not flocking to the radio hobbies in any great numbers - and - in many cases they lack the tube nostalgia gene. Sure, they know Collins was well regarded back in the day, but in terms of paying an elevated price? Nahhhhhhh... Too big, too old, better to give up that much space and cash to something more useful like an amplifier.

As for the older guys..... You know that story. Been there, done that, moved to a retirement place two years ago.
Logged

Never change a password on a Friday                
KE3WD
Member

Posts: 5689




Ignore
« Reply #2 on: September 03, 2012, 08:28:58 AM »

Sometimes a project is measured by how much is learned from the attempt to restore and not by whether or not said resurrection could be completed. 

73
Logged
W8JI
Member

Posts: 9296


WWW

Ignore
« Reply #3 on: September 03, 2012, 09:19:39 AM »

It's like buying a gutted 66 Mustang or 62 Chevy II coupe.

They were stable radios *for that time* with good conversion frequency schemes and PTO's, but the IF's and other stages were not exceptional anyway. I had 71A1's up through late 75A4's and they had great stability (compared to other BA radios) but not exceptional IF or detector performance.

You really have a treasure there if you want to experiment and learn, because it sounds like the best part of the platform is still good. If you buy a crystal filter for an ICOM or Yeasu 455 kHz IF you can cobble a much better IF system together.




 

Logged
W6OU
Member

Posts: 190




Ignore
« Reply #4 on: September 03, 2012, 12:52:38 PM »

I once purchased a Collins 75A-3 with a bad front panel, pitted chassis, and open power transformer for $100. Unusually, it had a 4:1 vernier drive. Over time, hams would advertise they were looking for certain 75A-3 parts. I sold the S-meter ($20), PTO ($35), cabinet ($115), slug rack cover ($20), round dial ($20), ps choke ($20), and audio transformer ($15). I kept the vernier drive, mechanical filter assembly, tubes, and knobs for myself. I made a few bucks and helped restore seven other 75A-3 receivers. However, you should realize there is a larger demand for 75A-3 parts than 75A-1 parts.
Logged
N8CMQ
Member

Posts: 362




Ignore
« Reply #5 on: September 03, 2012, 05:05:45 PM »

It's like buying a gutted 66 Mustang or 62 Chevy II coupe.

They were stable radios *for that time* with good conversion frequency schemes and PTO's, but the IF's and other stages were not exceptional anyway. I had 71A1's up through late 75A4's and they had great stability (compared to other BA radios) but not exceptional IF or detector performance.

You really have a treasure there if you want to experiment and learn, because it sounds like the best part of the platform is still good. If you buy a crystal filter for an ICOM or Yeasu 455 kHz IF you can cobble a much better IF system together.


I'd like to recreate my 63 Chevy II... I miss that rat rod...

 


Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!