[Johnson] Johnson T/R Switch 250-39 Function

[Carl]

Good point about using with a SS receiver but those are few and far between. 
I wont use my HRO-500 as a test bed!  I do use the switch with a 400W out AM 
TX and HRO-60 and its given no problem where it is mostly on 10M.

The 6BL7 is getting a bit pricey but still available. Mos probably go into 
the DX-60.

Carl
KM1H




----- Original Message ----- 
From: "Charles Ring" <w3nu at roadrunner.com>
To: "Don Ehrlich" <ehrlich at clallambroadband.com>
Cc: <johnson at mailman.qth.net>
Sent: Thursday, October 15, 2009 7:18 PM
Subject: Re: [Johnson] Johnson T/R Switch 250-39 Function


> The Johnson TR switch is as pure QSK as there has ever been. I have one
> with a bad power transformer,wondering if  a replacement can be found. I
> also don't remember whether or not the tube (6BL7?)  is available, and I
> don't know if it is safe to use with modern receivers.
>
> 73 de W3NU
>
>
> Don Ehrlich wrote:
>> I am thinking of bidding for Kevin's T-R switch.  I need to know if the
>> switch can provide near-QSK operation.  Does is use a fast switching 
>> relay
>> or is the transmitter connected to the antenna all of the time with
>> isolation of the receiver during transmit?
>>
>> Application would be with a Ranger and my SX28A where I am presently 
>> using
>> manual switching.
>>
>> Don K7FJ
>>
>
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