Simoco PRF28 Fixed Channel 800Mhz UHF Receiver module

Front badged as Simoco product, module PRF28 BUT ....


This equipment is actually designed and manufactured by RF Technology AUSTRALIA - very highly regarded RF equipment supplier to various industries

Eclipse 800 series of receivers & transmitters for UHF repeaters and fixed channel use

Model: R800B

Manufactured around 1995

Receiver frequency range 850 - 870Mhz

Complete module including front panel audio monitoring

Rear audio output via the gold RCA female socket

N type antenna connection

Currently set to the receive frequency of 858.4875Mhz (that is indicated by the white label on the front panel - removeable)

FULLY programmable via the test port, HOWEVER I do NOT have the monitoring/programming software.

Software required is called TecHelp (Dos) or Service Monitor (Win 95/98/XP)

I have seen a site online that does/did have the software (sm2k v2.2.3) but the site appears to have removed the .exe file

I do have the operating manual for this software and it would be VERY desirable to get your hands on the .exe file as you can not only program the module but also watch system parameters while in operation, especially interesting is the receive signal strength in dBm - I have included a screenshot of this interesting information (screen shot of the software in operation - NOT live from this unit)

Austech forum also appears to have members with this software. Much of the difficulty probably surrounds the fact it is propriety to RF Technology!

This unit was also designed for on board channel programming but this is disabled, access must be made via the serial port (DB9)

PLEASE NOTE: To use the 800Mhz band legally, you must have the appropriate licence from ACMA! Big changes are underway in determining the frequency spectrum use, here is some information below

http://www.acma.gov.au/Industry/Spectrum/Spectrum-projects/800-and-900-MHz-bands/803-960-mhz-milestone-transition-timeline

Fortunately I was able to find some specifications for this equipment:

Frequency stability 1 ppm standard ( TCXO ) Temp –30 to 60C

Sensitivity 0.25 uV (-119 dBm) for 12 dB SINAD, 0.35 uV (-116 dBm) for 20 dB Quieting

Spurious & Image Rejection 90 dB

Selectivity 80 dB at 25 kHz spacing per RS-204-C, 70 dB at 12.5 kHz spacing

Intermodulation 80 dB per RS-204-C

Modulation acceptance 7.5 and 3.75 kHz

Squelch Noise squelch, adjustable from 6 to 26 dB SINAD Carrier squelch, adjustable from 1 to 200 uV

Audio response 1 to –3 dB

Audio level 600 Ohm line adjustable from –10 to 10 dBm

Monitor output, 3 watts @ 4 Ohms

Discriminator & subtone output 1 V peak at 100% system deviation

Audio Distortion Less than 3 % at 1 kHz, 60% system deviation with 750 uSec de-emphasis

COS output Opto-coupled 12V, GND and free Switch connections

Alarms available:

Unlock, tuning voltage, signal strength, external mute and supply voltage

COSMETIC CONDITION:

No damage at all to the module, all buttons, indicators are fine

TESTING:

Hmmmmm, no signal generator now but I can tell you this

Powers up fine (via the attached/included external plug pack)

Burst of white noise and then the squelch takes over and it goes silent

I can manually open the squelch from the front panel adjustments

Both the Carrier squelch and Noise squelch adjustments can be set very fine, the adjustment is via 10 turn pots.

Local monitoring volume works fine.

All indicators function as they should

Audio is available (checked) from the rear RCA female socket

I am happy the receiver is functioning as it should although of course at the moment is it set to a "dead channel" as I have no means of generating a signal on this frequency at the moment.