I liked the idea of the ceramic based knife switch! That ought to take most
anything us hams could throw at it at pretty much any VSWR! :-)
Charlie, K4OTV
-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Tom W8JI
Sent: Sunday, October 20, 2013 6:39 PM
To: Joe Subich, W4TV; topband@contesting.com
Subject: Re: Topband: Antenna switch rating for high SWR?
The rub with any of this is the contact-to-coil breakdown.
----- Original Message -----
From: "Joe Subich, W4TV" <lists@subich.com>
To: <topband@contesting.com>
Sent: Sunday, October 20, 2013 12:57 PM
Subject: Re: Topband: Antenna switch rating for high SWR?
>
>> I know that T/R switches inside amps are fairly small in physical
>> size, however they are designed to operate into a fairly low SWR
>> load. I have no idea of what rating of a DPDT switch I would need
>> (per the diagram) in my application - perhaps I'm making a bigger
>> deal of something that isn't so critical.?
>
> Fire up ELNEC or your favorite modelling software and run your
> specific combination of flat-top length/height and feeder length
> to find out what the voltage and current are at the input of the
> feed line. That will tell you what you need for the relay.
>
> Remember, you can use *TWO* high voltage/high current "contactors"
> and mount them on Lexan or similar non-conducting surface to increase
> the voltage to ground rating if necessary.
>
> 73,
>
> ... Joe, W4TV
>
>
> On 10/20/2013 12:04 PM, John Harper wrote:
>> Morning all,
>>
>>
>>
>> I am planning to put in a DPDT switch (or relay) to allow me to easily
>> switch from using my 80m dipole as a vertical (T-top) antenna on 160m:
>>
>> http://www.ae5x.com/docs/antennas/160mT.jpg
>>
>>
>>
>> The dipole is fed with 450-ohm ladder line and used 10-80m in that
>> configuration so there is a high SWR on the line. I sometimes use a kw
>> output.
>>
>>
>>
>> I know that T/R switches inside amps are fairly small in physical size,
>> however they are designed to operate into a fairly low SWR load. I have
>> no
>> idea of what rating of a DPDT switch I would need (per the diagram) in my
>> application - perhaps I'm making a bigger deal of something that isn't so
>> critical.?
>>
>>
>>
>> John AE5X
>>
>> http://www.ae5x.com/blog
>>
>>
>>
>> _________________
>> Topband Reflector
>>
> _________________
> Topband Reflector
>
>
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