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Reviews Categories | Ham Repeaters | SEA ESP-1000 ACSB Repeater Help


Reviews Summary for SEA ESP-1000 ACSB Repeater
Reviews: 1 Average rating: 5.0/5 MSRP: $Unknown
Description: These stations were and are used in the 220-222 band that was taken away from hams years ago. It is commonly believed these stations cannot be modified to work on 222-225. IT is a lot of work, but they can be modified.
Product is not in production.
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K6ZRX Rating: 5/5 Jun 13, 2015 20:39 Send this review to a friend
A lot of work, but worth it!  Time owned: more than 12 months
It is commonly believed these stations cannot be converted to ham use. They can, but it is a lot of work and requires extensive knowledge of ACSB (Amplitude Compandored SSB) and microprocessors. The station is 20 watts PEP on transmit and RX squelch sensitivity is .08uV! The bandwidth of the transmitted signal is 4kHz, much narrower than narrowband FM. Working with ESP-520 mobiles the coverage is about the same as the 110 watt 2 meter machine at the same site, both with around 2.5dB gain antennas. Very impressive given the low power.

The conversion to ham use is very complex and requires proper test equipment to align on the ham band. With proper knowledge and equipment anyone can make these work. You must be very careful to tune the filters properly to prevent mixer products from landing in the military UHF aircraft band. Stations were generally sold in 5 radio trunking systems. Only one of the stations contains the master oscillator and it shares it with the other 4. The stations are useless without the master oscillator, and it is an odd frequency (12.275023MHz, .1PPM stability). The radio will not operate until it has been powered on for 10 minutes to allow the master oscillator to come up to temp. The display will show a countdown timer. Also, an external CWID will need to be used in a beacon mode since the station transmits a data burst every 10 seconds for the mobiles to track frequency and range. Also try to get the combiner/duplexer when purchasing since the radio use an odd offset.

If you are in a an area with no repeater channels available, ACSB can easily fit between FM channels without causing or receiving interference. A fun project for the more advanced ham. We have fun with our system which is linked to FM repeaters.
 


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