You could build a very nice full duplex repeater on a single
frequency that way.

Yes, except that the ARRL has decided to only petition for a waver for
single time slot TDMA, which can't be used for a repeater.

You're scheme would certainly work, and I too am wondering why nobody
has bothered to do it. Possibly because nobody really wants full
duplex (with echo, reverb, feedback, etc).

I wonder whether you may not also have to be really careful with your
transceiver/receiver switching design. You'll really need to be able
to trust (and drive) those PIN diodes properly... goof up on even a
single time-slice and you could put enough TX power into your receiver
to turn its front end into a pile of smouldering char in a millisecond.

This isn't a problem with normal split-frequency repeaters, thanks to
the isolation in the duplexer cans.

Do any of the commercial TDMA systems use the same frequencies for
base-mobile and mobile-base? My recollection is that TDMA cellphone
systems operate with split uplink/downlink frequencies.

No filtering, much less intermod issues in multi station at onee site
systems... all kinds of good comes of it.

Yep.

But "no filtering" comes with its own set of concerns.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
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