[Johnson] 250-39 TR switch.

[Carl]

Not worth it for one maybe usefull article.Ive been filling in the voids 
by finding full years on Epay and elsewhere for much less.

Carl


----- Original Message ----- 
From: "Peter Markavage" <manualman at juno.com>
To: <Johnson at mailman.qth.net>
Sent: Friday, October 24, 2008 12:23 PM
Subject: Re: [Johnson] 250-39 TR switch.


> Back issues of Electric Radio Magazine are still available from 
> Electric
> Radio.
> http://www.ermag.com/index.cfm
>
> Pete, wa2cwa
>
> On Fri, 24 Oct 2008 11:48:30 -0400 "Carl" <km1h at jeremy.mv.com> writes:
>> 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
>> >
>>
>>
>>
>
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