Pay attention to what you buy. The 220 stuff is
found under SEA, Intek, Securico, Midland and LMR
"Linear Modulation" brand names. Again there
are two ACSB formats in use and they do not
talk to each other.
I know of a group of "people" running around with
surplus ACSB units on simplex/talk - around/
direct. They were not able to get the units up
to the ham bands, but the mobiles will program
and work simplex in the 220-221 range.
About 2 years ago, you could have had the
SEA Repeaters all day long for $50 from Ebay.
skipp
> DCFluX <[EMAIL PROTECTED]> wrote:
> Anyone have an extra one of these repeaters they are willing to
> sacrafice for experimentation purposes?
>
> Seeing as 4K00J3E is an aceptable emission in the ham bands it has
> been decided to leave the modulation type the same (ACSSB). This
> would allow use of the surplus HT and mobile radios currently on the
> market and it apears to have advantages over FM.
>
> Taking a first glance at the schematic it looks to me that the best
> angle of attack is a chip that will sit on the control pins for both
> the RX and TX boards that will intercept the normal synthisizer
> command and replace them with what ever the command was and add a 2
> MHz off set to the channel with a jumper to add an additional 1.6
MHz
> on top of that for use in the other side.
>
> But I need some confirmations for this to work. Can the transmitter
> be freely assigned to channels 1-399 or is it stuck on 1 - 199?
This
> is because I need approx 1.22 MHz of channels and I would only have
> enough addresses for 1.00MHz if the transmitter can only get the 200
> channels.
>
> The concept would then be that transmit channel 1 = 222.0 MHz and
each
> channel incr would be 5kHz. Receiver channel 1 would be 223.6.
This
> would allow programing of the channels from the front panel instead
of
> burning a chip every time you QSYed the repeater. And theoretically
> it would allow the repeater to run "trunked".
>
> We could still get away with the 200 channels but the spacing would
> have to increase to either 10 or 15kHz, which ever is standard in
the
> 220 realm and that just wouldn't be as nice as the carrier is only
> taking up 4K of bandwidth anyway,
>
> Most of 220 is a mystery for me, so I would also like some
information
> on what the official band plan and channel spacings are. Not a lot
of
> kids on the block have 220 anything.
>
> On a related note, I think that the idea I have for a cheap
duplexer
> for 2M wont work very good there as the spacing needs to be 800kHz
> minimum for low insertion loss. so it should be cost effective for
> 220, where 1.6M is the split.
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