[Boatanchors] Antenna Relays & T-R Switches

[Carl]

Amen!

Diodes have fallen out of favor ages ago since they rectify from many 
sources from DC to daylight and feed IMD to the front end. Those signals 
also travel right back up the feedline and radiate.

The neon, not the little NE-2, properly biased can handle substantial RF 
should the relay contacts stick on the Dow Key. Not an AM KW but a 
typical 50-250W rig.
----- Original Message ----- 
From: "Bob Macklin" <macklinbob at msn.com>
To: "ROLYNN PRECHTL K7DFW" <k7dfw at clatskanie.com>; 
<boatanchors at mailman.qth.net>
Sent: Wednesday, November 05, 2008 6:41 PM
Subject: Re: [Boatanchors] Antenna Relays & T-R Switches


> Have you seen what a couple hundred watts of RF can do to a NE-2 or a 
> pair
> of clamp diodes. They will smoke for couple of milliseconds before 
> your
> input coils go up in flames!
>
> Bob Macklin
> K5MYJ
> Kent (Seattle), Wa,
> "Real Radios Glow in the Dark"
>
> ----- Original Message ----- 
> From: "ROLYNN PRECHTL K7DFW" <k7dfw at clatskanie.com>
> To: <boatanchors at mailman.qth.net>
> Sent: Wednesday, November 05, 2008 3:35 PM
> Subject: Re: [Boatanchors] Antenna Relays & T-R Switches
>
>
>>
>> > Which brings to mind a question I've wondered about..... why did 
>> > the rx
>> manufacturers of old never put a small fuse in the rx right after the
> input
>> jack, just in case?
>>
>>  ==============================
>>
>> Not necessary to add anything to the interior circuitry.
>>
>> Back in that era the common thing to do was connect a NE-2 across the
>> external antenna terminals (that's what I did 50+ years ago) or if 
>> you
> want
>> to be modern, put back to back silicon diodes across the antenna
> terminals.
>> This applies to a rx with a terminal strip for the antenna 
>> connection.
>>
>>
>> K7DFW
>>
>>
>> ..._._
>>
>> _______________________________________________
>>
>
> _______________________________________________
>