[Johnson] New guy

[Jerry K]

Mouser carries excellent replacement sealed 120V octal socketed relays for
about $13. They also have compact Dale 18K 7.5 watt resistors for R3 in the
VFO.
Jerry W5KP

-----Original Message-----
From: johnson-bounces at mailman.qth.net
[mailto:johnson-bounces at mailman.qth.net]On Behalf Of K6JEK
Sent: Tuesday, April 19, 2005 2:42 PM
To: johnson at mailman.qth.net
Subject: Re: [Johnson] New guy


Cecil,

I  don't believe Rangers ever came out of the factory with PTT
installed.  The manual contains a PTT circuit and instructions for
installing it but I don't think they ever came with the circuit
installed.  I wonder what picture you're looking at.

Incidentally, you've stumbled onto one of the controversial areas.  The
Johnson PTT circuit is a bit of a hack.  It unkeys the transmitter and
relies  on the clamp tube to pull the screen of the 6146 down in
PTT-off.  This works fine but draws more current and dissipates more
heat than you might expect while sitting there listening to the rest of
us ramble on.  As I recall, the PA and modulator combined dissipate
about 50W with PTT off.  It also puts something like 200V on the PTT
line, say the coiled cord of the old D-104 you bought at the flea
market.  Make sure that insulation isn't frayed.

This has led to all manner of different PTT circuits being created and
installed many of which are arguably even worse.  Some do a nice job of
reducing power dissipation during PTT off but disable CW on the
transmitter.  I've seen some that increase the shock hazard.   If you
have what amounts to the Johnson PTT installed.  I'd get it to work
before I jumped on some other PTT scheme.

Jon

On Apr 19, 2005, at 11:15 AM, Cecil Acuff wrote:

> Hey Folks...
>
>        Thanks for all the responses of welcome and suggestions.  As
> evidence that I have a lot to learn....the PTT relay that I thought
> was a mod may just be factory with a replacement relay.  I found some
> pictures of one on the auction site that has the factory PTT which I
> didn't know existed.  Good thing I didn't begin the removal....might
> have been a mistake.
>
> It looks like a  sandwich type octal tube socket mounted on standoffs
> to the chassis behind the rectifiers.  What made it look so bad was
> the melted down plastic cased relay.  The pictures of the unit
> equipped with the factory PTT shows an open relay.  Any way to confirm
> this is factory in my radio?
>
> Also I didn't mention it but we are talking about a Ranger I.  It has
> the Round meter shield...looks like some are square.  Maybe that
> better dates it as an early or newer....or factory assembled vs kit?
> Don't know!
>
> Again Thanks for the help!
>
> Cecil..
>
> 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
>

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