[R-390] Re: Tube shields? We don’t need no steenkin' tube shields!

Barry Williams ba.williams at charter.net
Tue Dec 4 21:24:44 EST 2007


I think the original subject was either started by Chuck Rippel, or it 
quoted him, on RF isolation for certain tubes in the R-390A. That's why 
the shields were recommended by Chuck for those specific tubes. Then, 
the discussion branched off into tube shield types, best heat 
dissipation, etc. This may have been about 10 years ago from what I 
remember.

Luckily, between 2 A's and a SP-600 from Al Parker who gave me a ham 
price on it, I have more than enough for the right IERC tube shields.


Barry

p.s. Thanks again, Al! It's still a great radio.


> The only reason I ran this test was because of the different types of 
> "inserts" in side the various shields. Pete's website page is great 
> reading. Also, Electric Radio Issue 66 had another great article by 
> Bill Kleronomos.
>
> If I had a complete set of the IERC types with the finger grip type 
> insert for the SP-600, I would use them. But, I haven't used tube 
> shields for several years and have no tube failure problems.
>
> Les
>
>
> ----- Original Message ----- From: "pete wokoun, sr." 
> <pwokoun at hotmail.com>
> To: <r-390 at mailman.qth.net>
> Sent: Tuesday, December 04, 2007 9:50 AM
> Subject: [R-390] Re: Tube shields? We don’t need no steenkin' tube 
> shields!
>
>
>
>
> About three years ago I did a study and put out a paper on the 
> effectiveness of these IERC heat shields.  It shows the effectiveness 
> of these things with temperatures.  Great of Les to do more testing.
> You can view that paper here:
>
> http://www.qsl.net/kh6grt/page4/shields/shields.htm
>
> Pete
>
>



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