[Premium-Rx] Watkins Johnson 8711A Repairs after 10 Years

[Francesco Ledda]

MTBF, etc. are theoretical based on a bunch of assumptions, number of nets, components, derated operational  values of the components and statistical distributions; these numbers have contractual meaning related to minimum performance in certain working conditions. All this doesn't tell you much about when our loved radios are going to fail!

Sent from my iPhone


On Jul 30, 2013, at 17:10, "Michael O'Beirne" <michaelob666 at ntlworld.com> wrote:

> Dear Bob and the others,
> 
> You can go back an awful long way and find plenty of ancient radio still working and likely to do so for the foreseeable future - vastly longer than any design life thay may have had.  This is because most of it was very solidly made, there is a solid core of enthusiasts prepared to keep their treasures working and also because there seems to be a huge stock of valves ("tubes" to most of you!!) available and the small components are reasonably plentiful.  My RA17s and AR88D march on as well as my Racal RA3701 and not so new RA1772.
> 
> I cannot imagine many owners of tubed Collins or Racal gear are looking for the garbage collection man!!
> 
> Here in the UK Yahoo groups such the WS19 group have international user and technical support and on-line access to an impressive library of old military technical manuals and user instructions.   The recent release by our MOD of their holdings of Clansman tactical HF and VHF gear (early 1980 vintage) at pretty reasonable prices has increased the interest since this kit is compact, portable and extremely well built to MILSPEC standards.
> 
> Of course no one would pretend that their stuff can compare with the latest direct sampling offerings from DRM or R&S, but (and I hope no one will take this badly) some people feel that ancient radio is more fun to operate than a faceless black box.   The problem, however, is not the radios but the fewer and fewer AM stations to listen to as more commercials migrate to satellite and / or on-line distribution.  To that I fear there is no answer.
> 
> 73s
> Michael
> G8MOB
> 
> ----- Original Message ----- From: "Bob Betts" <rwbetts at sbcglobal.net>
> To: <premium-rx at mailman.qth.net>
> Sent: Tuesday, July 30, 2013 7:25 PM
> Subject: Re: [Premium-Rx] Watkins Johnson 8711A Repairs after 10 Years
> 
> 
> Gary, Steve and All: