DCFluX,
From what I saw the xmtr VCO (as is the rcvr VCO) is phase locked to the
synth. which uses the 10.235 MHz reference. The xmtr VCO operates 10.235 MHz
above the carrier freq. ( 220.005 + 10.235 = 230.240 MHz). The xmtr VCO output
is mixed in a DBM with the 10.235 MHz ref. to get the output freq. If the VCO
was mixed in the DBM with another freq. not the ref. freq. (ie. 230.240 -
224.005 = 6.235 MHz) then the xmtr would operate 224.005 to 225.000 MHz. You
would then need to freq. ( or phase ) modulate the difference freq.( ie. the
6.235 osc.) at the desired deviation ( +- 5.000 KHz ) for an FM output (good
luck), or do a +- 5 KHz modulated PLL at 6.235 MHz (again good luck with your
FM gravy ). Perhaps you could do +- 1 KHz FM of an xtal osc. at 1/6th of 6.235
MHz ( 1.0391667 MHz ) and use the 6th harm. to get the deviation needed (yuk).
Don't forget the xmit audio processing is not the same in a ACSB xmtr as in an
FM xmtr.
The ACSB rcvr operates above the xmtr from 221.005 to 221.995 MHz so the
programing of the rcvr for use in a rptr from 222 - 225 MHz would need to be
different than the xmtr, high in low out vs. low in high out on 222 - 225 MHz.
The rcvr IF is 10.235 MHz if I remember correctly. Here an outboard
quad.detector on 10.235 MHz of some sort would be needed for recovery of the
modulation, if the +- 5.0 KHz modulation deviation ever made it thru the rcvr
IF +- 2.5 KHz xtal BPF.
Allan Crites WA9ZZU
DCFluX <[EMAIL PROTECTED]> wrote:
I seen it once, I just lost the PDF and need to find it again.
The first priority was going to be to run it in ACSSB in the 222 to 225 MHz
region with 1.6MHz split instead of 220-222 1M. NB-FM would be the gravy.
On 4/26/07, allan crites <[EMAIL PROTECTED]> wrote: DC,
The model no. is ESP1000/ESP1000M and the master base station oscillator
(MBSO)
that operates at 10.275 MHz is contained in only one of the rack combination
of up to 5 xmtrs. The manual is 1 1/2 " thick and is very complex. I look
forward to hearing how you expect to accomplish conversion onto NB-FM having
not seen the manual.
AC
DCFluX < [EMAIL PROTECTED]> wrote:
I always wanted to play with brute force hacking a SEA repeater onto
NB-FM and into the ham band. Anyone remember what happend to the .PDF for the
service manual and know anyone that has one to get rid of cheap? I would like
the version that has the master reference oscillator but I cannot even remember
the model number at the moment.
