[TenTec] 262G power supply - no rest for the weary

[Douglas]

>Date: Sat, 4 Apr 2009 10:15:12 -0400
>From: "Mike Hyder  -N4NT-" <Mike_N4NT at embarqmail.com>
>Subject: [TenTec] 262G power supply - no rest for the weary
>To: "Ten-Tec Reflector" <tentec at contesting.com>

>Some time ago I bought my first Ten-Tec rig, a Triton 544 with a 262G >power supply.  That supply has a speaker and a built-in VOX circuit.

>After spending hours trying to make the VOX circuit work correctly  ( I 
>don't work phone but do want things to work ), I gave up and called >Garland Jenkins, then a super-technician at Ten-Tec for advice.

>To paraphrase Garland:  "That VOX circuit will not work in an RF 
>environment."

>Who'd a thunk it?

>Mike N4NT 

The 262G power supply with VOX is a well known design goof from Ten-Tec. They have admitted it for years.

It's almost impossible to get the VOX to work correctly with the unshielded zip code interconnect cables that they used, the plastic cabinet sides, etc, etc. Can it be made to work? Theoretically yes if you change out all the cabling, line the cabinet with foil shielding or some other method, install bypass caps, ferrite cores, etc.

It's not a matter of RF in the shack in the sense of stray RF. I had a 262G and if one was within about 100 ft of a radiating antenna, there was too much RF present for the VOX to work properly. Now if your station was housed in a Faraday shield...

The late Lew McCoy/W1ICP of the ARRL was rather critical of the Triton series of transceivers and their power supplies mainly due to the plastic sided cabinets that Ten-Tec used. The rigs perform well but the lack of shielding for some functions was annoying and not the best design practice.

73,

Doug/WA1TUT