Philadelphia's repeater activity started around 1963 with a
repeater on 146.34/146.94 owned and operated by W3CKP. About
the same time K3DSM put on a 146.94/52.525 repeater. Since
these were personal repeaters they were available only when
the owner was available or wanted them on.
There were hard feelings against a personal repeater since
only one person had the say on how, when and what the operation
was to be. As a result some 30 FM'ers met on November 1, 1967
at the WFIL studio's in Philadelphia to organize a club. The
Main Line VHF Association, an inactive club, was chosen to
simplify matters since it was still licensed and several of the
old members were active FM'ers at the meeting.
A split-site repeater on .34/.94 was put on the air that night
with the transmitter at K3DSM's home in Merion and with the receiver at K3JPB's home in Newtown Square. A 449 MHz link
connected the two sites. W3CKP discontinued operations.
Different locations were tested for coverage. The biggest
problem was finding the best location to serve the most FM'ers.
The area has numerous hills and the terrain didn't help matters
no matter where a site would be located. Major site locations
tested with fair results were Lankenau Hospital, Sellersville
(old Western Union tower) and Berwyn Roller Rink. Berwyn proved
to satisfy more people. Immediate preparations were made for a
single site repeater at Berwyn. Receiver desensing was really
bad.
In May of 1968, the Expo in Paramus NJ solved one of our biggest
problems. We obtained a duplexer, a 4 cavity ring device, to
allow one antenna to be used for transmitting and receiving
without desense. Another problem was frequencies we were using.
There were 10,000 reasons not to have a repeater on .76 and an
equal number for not having it on .94. The club changed back
and forth several times trying to please everyone which we
finally found impossible. .94 was terrific coverage into
Allentown some 55 miles away. Yet to the East there was a
coverage problem 5 miles away.
Meanwhile another group, WA3IPP, put on a very good repeater in
Sellersville on .28/.76. This repeater had very good coverage
but was not solid near the city. It gave WA3BKO Berwyn lots of
competition.
While the repeater was at Berwyn many improvements were made
such as the addition of a mechanical wheel automatic ID, tape
logging, hardline and a stationmaster antenna raised 40 feet
above the rink. Control on 449 MHz with Secode had it's
problems since the control receiver's IF was listening to Radio
Moscow. The whistle-off feature had it's short-comings since
testing disabled the system when anyone whistle-tested.
Simplexing on .34 among other anoying tactics finally called for a change of sites. Swarthmore was really poor. Coatesville
covered Baltimore better than Philadelphia. Edgemont did not
cover any better. The club wanted to go back to .76 but
Sellersville was there now. It was decided to try to share the
.76 frequency. WA3BKO was now in Penn Valley, central to the
area to be covered. The duplexer could not operate on this pair
of frequencies. The receiver was placed in North Philadelphia
and linked on 449 MHz. Another receiver was placed in Devon
also linked on the same 449 MHz frequency. Receiver selection
was accomplished by hoping only one receiver heard the signal. Sellersville sent their .28 input to Penn Valley on another
449 MHz frequency. .34 and .28 could both access the .76
transmitter. At this point Sellersville transmitter was
disabled. Power was raised, at Penn Valley, to equalize
coverage.
On December 7, 1970 a vote was taken to merge the two clubs
and form PARA.
Thanks to Gene K3DSM
for the history of the Main Line VHF Association.
