[Boatanchors] Electronic T/R Switch vs Coaxial Type

[Jim Brannigan]

What about the DOW-KEY DKC-TRM-1 T/R switch?
I used one many years ago with a CE-20A to 811A amp and a 75A3.

Unfortunately the antenna switch was the fastest part of the TR process and 
the other switching and receiver recovery lags prevented true break-in.
True break-in was not realized until I bought a Ten-Tec radio.

Jim

> I, like Pete have been running a Johnson TR Switch on the output of a 
> BC-610.  NO TVI!  I monitor the output of the BC-610 with an SM-220 
> w/BP-8.  I also feed my receiver's IF into the SM-220.  I observe NO TVI.
>
> I believe that those getting TVI are mistakenly relating the source as the 
> TR Switch.  I only see TVI when over modulating an Apache.
>
> Bob - N0DGN
>
> Peter Markavage wrote:
>> I've run a Johnson T-R switch on the Johnson Thunderbolt for years and
>> not experienced any TVI related issues. I also have a Dow-Key relay on
>> the back of my Apache that's been there and working since around 1960/61.
>> The Dow-Key on the back of my Viking II has been there and running since
>> 1955. These relays were some of my better investments.
>>
>> Pete, wa2cwa
>>
>>
>> On Tue, 4 Nov 2008 10:36:39 -0800 "BLIMPY" <blimpboy at sonic.net> writes:
>>
>>> Biased vac tube T/R switches have bad reputation as TVI generators. 
>>> Many
>>> in-line filters are not tolerant of impedence mis-matches expecially 
>>> those
>>> with  reactive components.
>>>
>>> Run of the Mill Dow Key are second rate relays.. compared to Advance 
>>> Coaxial
>>> Relays.. which are available for less money and will give no grief due 
>>> to
>>> unscheduled liberation of smoke.  Some BNC commerical application 
>>> surplus
>>> relays  with dc  may be contradict this generality.
>>>
>>> a vox type t/r switch might be a workable compromise, but not true 
>>> break-in
>>>
>>> good luck
>>>
>>>
>>> _______________________________________________
>>>
>>>
>>>
>> _______________________________________________
>>
>>
>
> -- 
> Bob - NØDGN
>
> _______________________________________________