[Milsurplus] [RCA] SRR-13 Article, more

[Kenneth G. Gordon]

On 2 Aug 2016 at 9:41, Hubert Miller wrote:

> 
>     I don´t think it´s correct to give a blanket assessment of submini tube longevity. 

I don't. Look at the Sylvania specs for CERTAIN subminis.

>     The proximity fuze tubes WERE built to
>     withstand extreme G forces, but i really doubt the run of the mill portable radio 
>     tubes were anywhere near the same
>     kind of standards.

Of course not. Hearing-aid tubes, on the other hand...

> Some of the submini tubes ( 5676 comes to mind ) were 
>     actually rated for 100 hours life. Which
>     reminds me, i have a grid-dip meter that uses this tube; maybe i should be 
>     thinking about an FET replacement, which
>     would also eliminate the 67.5 volt battery.

There is a fellow I ran across who sells his products on eBay who makes FET versions of 
various tubes. The 1L6 is one of those. I bought a solid-state 1L6 from him and had him 
make me a 1T4 version for my R-1004. They are superb.

>      
>     BTW - one fellow on the regen receivers group built a small regen receiver using 
>     proximity fuze tubes he had on hand,
>     and reported the tubes´ performance seemed to degrade in a short time, in 
>     hours. This is only anecdotal, but i wonder.

Not anecdotal. Proximity fuse tubes were purposely designed for a very short life. Another 
such are radiosonde tubes.

>     The SRR-13 doesn´t have any kind of cooling provisions, is that correct?

Correct. No vents to the outside at all. Completely sealed up.

>     Which reminds me, i have somewhere one of those Navy SSB low-power exciter 
>     / receivers that was notorious for
>     failures due to, i believe, tight packaging and cooling. Another item whose 
>     disposition i need to decide.

Interesting. TMC, perhaps?

Ken W7EKB