PDR 3500

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This is a page about the PDR3500 Transportable Repeater, a portable version of the Quantar. The come in an attractive case, and with flexible power options.

These are cool stations that take the standard Quantar modules. They are able to be powered from AC or 13v DC power, as the internal amplifier is 12v DC powered. The internal supply can work on 85-250V AC 50-60Hz, and there is a DC input for 13.8v at 10a. The unit weights about 50 lbs with the duplexer.

PDR3500, Dildo for Scale

The station backplane is different here in that the PA ID is set using a 4 bit dips witch on the unit. This also adapts the SPECTRA PA module to the Quantar exciter, fooling it into thinking it's a Quantar PA.

The PDR3500 can be operated with the case closed and locked (using a Chicago 2135 key) with the power and coax going out the left side of the unit through a gasket.

PDR3500 cable gasket

These were common for FBI/USSS/WHCA meaning the UHF1 was the most common (403-433), but they can be changed to UHF 2 with a module swap or via converting the units. The Spectra PA in UH1 works up to 470 MHz at reduced power and up to 465 with the full 30W. Being these were used as a backup it's common to find the 8 wire Wireline card in them. Most were later production modules so they have EPIC V modules.

It is possible to add a v.24 card on these and route the v.24 out of the chassis.

Of note when programing it, and especially for flash upgrades, the serial port on the top is the Back Port and uses the IP address and BP config for SLIP. I've never been able to flash these at 38400, and have always needed to use 9600 bps.

Changing Bands

As the unit takes the standard modules, you can easily change bands by moving modules. The issue is the PA is an adapted from the SPECTRA Mobile radios, and uses the same PCB but mounted on a custom heat spreader.

A and B RJ 45

These are the wireline interface. As the PDR manual doesn't give them anywhere they are below.

PDR3500 - A - J21
RJ45 Color Function
1 W/Orange LINE1 +
2 Orange LINE1 -
3 W/Green LINE2 +
4 Blue LINE2 -
5 W/Blue Ground
6 Green RDSTAT +
7 W/Brown RDSTAT -
8 Brown EXTPTT -

PDR3500 - B - J22
RJ45 Color Function
1 W/Orange LINE2 +
2 Orange LINE2 -
3 W/Green LINE1 +
4 Blue LINE1 -
5 W/Blue Ground
6 Green 5v @ 1A
7 W/Brown EXTPTT +
8 Brown Ground


PDR 3500 Transportable Repeater Basic Service Manual - This has the backplane diagram and layout in it as well.




Chassis And Backplane

Power Supply Module




UHF R1 PA Module

Note this is the module from an Astro Spectra/Spectra mid power unit