[Heathkit] SB 100 & a PL239 connector

[Sandy]

Eons ago, I was employed in a shop that did two-way and taxi radios.  Most of my work
was aboard boats and ships, but if things got slack, I was turned into a "land
mobile" technician.  Amungst the nasty radios worked on were some old
delapidated RCA CMU-15 "Carfone" UHF sets.  These were full of RCA phono
connectors ( albeit nice insulated ceramic or teflon ones!)  I groused to the 
ex- RCA tech that worked there (W5YCR, Bob...now SK from cancer).
He explained that they found less loss and hardly any 'impedance bump' at
all compared to other connectors, notably the "UHF" series (PL-259/SO-239)!
Motorola also used them as well.  Ever since I have had a different outlook on
the "lowly" phono plug and socket!  There are some really crappy ones
made, but of you get some good ones, they are amazingly good at VHF/UHF
RF ranges!
Regarding the much used (And I think really crappy) PL259's.....We had untold
problems with repeater cavities and duplexers on 2 meters with these connectors.
After they were all changed to "N" series, the problems were very few!  Cavities
started tuning like they should and acting "right" with little leakage effects.  I 
remember from my avionics days watching an FAA tech very carefully assemble
"N" connectors being used in patch panels and interconnecting harnesses when 
they were building the HRV VORTAC station at Callender NAS New Orleans.
He raved and said they used nothing else for the interconnects as they were RF tight
and gave little trouble.  Of course all our UHF gear used them too on the aircraft.
TACAN and some other higher power stuff went to the "HN" series.  L<ast VHF
set that used the PL-259 as I remember was the old ARC-3.
73,
Sandy W5TVW

----- Original Message ----- 
From: "Glen Zook" <gzook at yahoo.com>
To: <DStraz at aol.com>; <heathkit at mailman.qth.net>
Sent: Thursday, December 30, 2004 9:58 AM
Subject: Re: [Heathkit] SB 100 & a PL239 connector


| Believe it or not, a properly installed RCA connector
| is a better "match" to 50 ohms than the UHF (PL-259 /
| SO-239) connector.  Up to at least 1 GHz (and often
| even higher frequencies) the RCA compares very
| favorably with the type "N" except that it cannot
| handle any where near as much power.
| 
| Collins, Drake, Heath, and several other companies
| used the RCA connector for r.f. as well as control and
| audio purposes.  The company engineers did know what
| they were doing!
| 
| Glen, K9STH
| 
| 
| --- DStraz at aol.com wrote:
| 
| Could some help me  with the proper way  of converting
| the phono jack antenna plug to a PL 239 connector.
| 
| 
| =====
| Glen, K9STH
| 
| Web sites
| 
| http://home.comcast.net/~k9sth
| http://home.comcast.net/~zcomco
| 
| 
| 
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