[Johnson] 250-39 TR switch.

[Carl]

OK, thanks.

Now does anyone have a copy of that April 1993 article they will share?

Carl
KM1H


----- Original Message ----- 
From: "Peter Markavage" <manualman at juno.com>
To: <Johnson at mailman.qth.net>
Sent: Friday, October 24, 2008 11:04 AM
Subject: Re: [Johnson] 250-39 TR switch.


> There is a simple online Electric Radio Index. Covers all the issues 
> from
> day 1 and continues to be updated every month.
> http://home.wi.rr.com/n9oo/ersearch.html
>
> With a few simple key strokes, Dennis's article pops out in the list.
>
> Pete, wa2cwa
>
> On Fri, 24 Oct 2008 10:38:51 -0400 "Carl" <km1h at jeremy.mv.com> writes:
>> Do you remember which ER issue?
>>
>> Carl
>> KM1H
>>
>>
>> ----- Original Message ----- 
>> From: "Dennis" <radioart at charter.net>
>> To: <kb2wig at twcny.rr.com>; "Roy Morgan" <k1lky at earthlink.net>
>> Cc: <Johnson at mailman.qth.net>
>> Sent: Friday, October 24, 2008 8:16 AM
>> Subject: Re: [Johnson] 250-39 TR switch.
>>
>>
>> > Another point of view on these TR switches....
>> >
>> > I have three of them in use and they work great.  As long as you
>> keep
>> > the connection between your transmitter and the TR switch short
>> the
>> > suckout mentioned will be slight; its because of this issue that
>> > Johnson put an RF amp in the TR switch so signals won't be
>> degraded.
>> > You will notice some changing of signal levels when you change the
>>
>> > loading on your transmitter; but thats normal.  In my case I have
>> my
>> > CE 100V & 600L coupled with a NC-303 using a Johnson TR switch and
>> I
>> > have two Johnson Desk KW's using the Johnson TR switch and they do
>> a
>> > great job.  Into a 50 ohm load they will provide you over 4kw of
>> > switching protection to your receiver.....  Not too bad...
>> >
>> > With regard to the TVI, not an issue any more with cable and
>> satilite
>> > but in the good old days Johnson recommenced using a Low Pass
>> filter
>> > with the TR switch;  In those days most shacks already had a LP
>> filter
>> > in the antenna line, I know I did, is it wasn't ever an issue....
>> >
>> > I remember I wrote an article for ER (Electric Radio)  magizine
>> > discussing the many different TR switchs and their pros and cons.
>>
>> > Maybe you can get a copy....
>> >
>> > Ciao, Dennis, k0eoo
> Johnson mailing list
> Home: http://mailman.qth.net/mailman/listinfo/johnson
> Help: http://mailman.qth.net/mmfaq.html
> Post: mailto:Johnson at mailman.qth.net
>