The PURC5000 came in two versions -
Early CxxJLB stations, similar to early MSFs, where the 2732 eprom is
programmed via the R1801 for frequency, etc.
Later CxxJXB stations, while similar to later MSFs, DID NOT need RSS.
There is a 10 or 12 button keypad, and a red LED scrolling display
(similar to the later NUC stations), which can be used to set a
number of station parameters, such as frequency, key tones, etc.
HOWEVER, in order to be able to change the frequencies, there is a
DIP switch on the control board that needs to be turned on to allow
the changes to take effect. Otherwise, the display will show the
current frequencies programmed for CH1,CH2, etc, but itnot accept
changes.
Most of the PURC5000s came with a link receiver drawer just below
the HSO. This is simply a tray with a Micor RF/IF board, a Micor
style audio/squelch board (usually modified for flat audio by using a
different resistor value in the preamp op-amp stage before the PL
filter in/out), and usually a DPL board. Plus there is a verticle
interconnect board to tie it all together, supply regulated 9.6v and
12v from a single 12v feed, and provide all signals out to a 10-pin
header connector. This header connector then ties to the MSF5000
control board via a 10-conductor ribbon cable.
I've taken these receiver trays out of old PURC5000s, swapped the
70MHz RF/IF board with a 450 mobile RF/IF board, swapped the DPL
board for a PL board, and wired a 8-conductor shielded cable from the
interconnect board out to a DB9 connector, and ran a fused DC power
cable into it. Makes an excellent voting site receiver, or a great
repeater receiver if using a repeater other than a Micor Compa-
station.
I think I still have a stack of them in my shop. I kept a few for ham
project when the last of the PURC5000s were decommissioned.
I can still remember years ago when my Motorola rep would make his
monthly lunch visit. One day he excitedly called me to tell me he was
bringing me a new protoype paging transmitter - 300 watts, and he
could carry it in the trunk of his sedan with only one person needed
to lift it in and out. Thinking of the 300w PURC5000s, which weren't
in the shallow compa-station cabinets like MSFs, but rather in 6ft
tall 24 square cabinets, requiring an army to move, we thought he
was crazy, until we actually saw it in his trunk. Shortly thereafter,
60 PURC5000s went to the boneyard, and over 300 Nucleus stations soon
followed.
Some Motorola trivia - while the PURC5000 was a retrofitted MSF5000,
the Quantar actually was derived from the Nucleus station, which came
first.
Speaking of Nucleus stations - anyone wanting to make a 900 Nucleus
into a repeater - keep your eyes out for what was known as
an ADVANCED CONTROL Nucleus - basically, instead of an NIU (Network
Interface Unit which is fed via a satellite synchronous RS232 data
stream link), the station came with an Advanced Control board, which
allowed either a standard RF link receiver or wireline control.
Early versions included a PURC500 style receiver tray bolted below
the power amplifier (same receiver as the PURC5000s mentioned above),
while later versions utilized the internal card receiver (like a
Quantar).
The link control card is matched to the Station Control Module (SCM),
so when switching out the link control card, the SCM also needs to be
replaced. Later version software also required the exciter to be
replaced whenever the SCM is changed, as they are known as a matched
pair which is factory aligned.
The advantage of the Advanced Control version is that the exciter
can be modulated in the analog domain - perfect for amateur use.
Unfortunately, this version is extremely rare, and only a handful
were sold. It was designed as a replacement for the later PURC5000.
The main market was those who had RF or wireline linked PURC500O
simulcast systems, and needed new units for coverage expansion during
the period after the PURC5000 was discontinued. But by that time,
most of the larger paging carriers went to satellite-based linking of
their simulcast networks, and mass converted to NIU-based NUCs, thus
the reason they are so rare.
BTW, if any of you have any 900 NUCs sitting in your warehouses, I'll
buy as many as I can find. Let me know...
Eric
KE2D
--- In Repeater-Builder@yahoogroups.com, Mike Morris WA6ILQ
[EMAIL PROTECTED] wrote:
What keypad???
The PURC 5000 does not have a keypad.
The Nucleus does, however. It is the Quantar-based paging
transmitter that came after the PURC5000.
The real PURC 5000 came in two flavors.
Is there a three digit display on the top right of the panel? If
so,
then it takes RSS.
If there is no display then it takes a 2732 family PROM.
The MSF page at repeater-builder has all the gory details.
Mike WA6ILQ
At 09:08 PM 10/24/07, you wrote:
Can the station be programmed via the keypad or does it take RSS?
Randy
Jay Urish wrote:
I
