[222mhz] ACSB

[Dr. Gerald N. Johnson]

On Tue, 2007-11-06 at 21:40 -0500, Glenn Little WB4UIV wrote:
> Is there anything that prevents hams from using ACSB?  There seems to be a 
> lot of ACSB 222 MHz equipment showing up.
> 
> I was given a ESP1000 trunking system to get it out of the shed.
> 
> Has anyone converted one of these to 222-225 MHz? Sea says lots of luck!. 
> The manual does not describe the method of setting the synthesizer on 
> frequency.
> 
> 73
> Glenn
> WB4UIV
> 
The higbband ACSB board and manual I acquired decades ago wasn't all
that wild for circuitry. Those days it was probably crystal controlled
with the control tone about 3 KHz. That operated the squelch and the AFC
and the only odd thing in the receiver was an audio low pass filter with
a notch at the tone frequency. The major oddity in the transmitter was
sending that tone with the voice audio.

A trunking system may be difficult to get set on a ham frequency without
it wanting to get a command from the trunking control. Might have to
find the control port of the synthesizer and cut that away from the
trunking internal control and set up a PIC chip to drive it, which is
likely to be serial.

Its likely that a 222 SSB ham station only needs to cover 222.050 to 222.125, 
if that much so it might be that a VXO and multiplier might replace the
synthesizer. Then if you drop the transmitted tone, its simply a dedicated 
SSB rig compatible with the ham rigs already on the band.

73, Jerry, K0CQ