[R-390] EAC R-390A parts needed

[b w]

Hank,

Good to hear from you again. It isn't a big thing on the tube shields 
and dust covers, but the -20 manual does state that the dust covers 
should be removed if not used in extremely dusty conditions. I think the 
same paragraph in chapter 2 is where Chuck got his suggested group of 
tubes to be shielded. These are: V201-V206, V505, and V701 if used in a 
fixed installation.

The only point that I would quibble on is the type of shields. I posted 
a resend of the study of no shields, shiny, black, and IERC shields last 
year. The measured temps was convincing data for tested tube life. I'll 
dig around and see if I can find it again. The shiny shields were the 
worst of the lot, and worse than tubes with no shields at all. They 
always increased tube temps.



Barry nonHauser

> I find it extremely interesting that after Collins designed these 
> GREAT radios and they were built to work 24/7/365 with covers, 
> shields, adverse operating conditions, voltages all over the scale, 
> vibration and i could go on forever.
> Then the radios became available to to public domain, then all of a 
> sudden a whole new bunch of WANNABEE redesign engineers come up with 
> all of these far out theories and solutions to further their case or 
> mostly their pocket books to sell the SS replacements for a perfectly 
> working ballast tube or to enhance the audio, which is fine. It was 
> not designed to be concert hall performer. It was designed to listen 
> some of the worst signal reception signals in the world for the state 
> of the art at the time.
> Covers and shields were there for a reason.
> The Spec's say how and where the radio was DESIGNED to OPERATE.
> The enhancements help to some extent.
>
> We all remember our lost somewhere in the Louisiana swamps Nolan Lee 
> and his radio that ran over 7 years 24/7 with out a 3TF7 failure and 
> with voltage fluctuations up and down with covers on and all shields 
> in place with it meeting the same spec's (period)
>
> Recap yes. align yes, then plug and play and pass it on to first your 
> born still running.
>
> IF IT WORKS WHY FIX IT????
>
> My .0002 worth.
>
> Hank
> KN6DI
>
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