What little I can tell is they are telco references so there may be
something good inside OCXO or RB. It looks like it runs on -48VDC from the
ebay pix. Its output could be any of the typical telco references that are
not 5 or 10 MHz. These are pure guesses. The Price seems reasonable.
Good luck
Paul
WB8TSL

On Sun, Jan 10, 2016 at 6:48 PM, Adrian Godwin artgodwin@gmail.com wrote:

Hi

Unless we are looking at different auctions, that one appears to want 13.8 V at <= 5A
as the supply.

The BNC’s are also a fairly rare item in the Telco inventory (but not unheard of).

If I had to bet, I’d say it’s a piece of mobile video gear. I would not bet anything over
about a nickel on that being correct. It’s very much a mystery item other than possibly
having an offset frequency translation function.

Bob

Tait is a major mobile comms manufacturer-head office is here in
Christchurch, NZ-a couple of miles down the road from me.
The T801 is/was often used in simulcast systems (which seem to be peculiar
to the UK)  to lock up several base station equipments to a common
reference-which is usually a 12.8 MHz high quality OCXO.  But I suggest you
ask a few pertinent questions of the vendor to find out more about that
particular box, as it may be slightly different, depending on where it came
from.
DaveB, NZ

----- Original Message -----
From: "Bob Camp" kb8tq@n1k.org
To: "Discussion of precise time and frequency measurement"
time-nuts@febo.com
Sent: Monday, January 11, 2016 4:00 PM
Subject: Re: [time-nuts] Tait reference

Hello,

Tait T800 is a series of mobile radio repeaters, so probably the T801
could be a unit intended for iso-frequency networks, in which there are
several repeaters are distributed in a wide area operating all at the
same frequencies with a very tight tolerance. BNCs and 13.8V power
supplies are very common in the mobile radio networks world.

Regards,

Javier

On 11/01/2016 4:00, Bob Camp wrote:

Adrian wrote:

Tait is a manufacturer of mobile communications gear in New
Zealand.  The T801 was part of a discontinued "quasi-synchronous
communications system" -- a form of simulcasting on the same
frequency by transmitters at different locations, to fill in dead
spots.  Tait's application was utility and public service mobile
radios (not radio broadcasting, where this scheme has also been
used).  Here is Tait's basic description:

This suggests that the T801 does not have an internal frequency
reference, but rather requires a precision external reference to
function.  (It has a jack labeled "INTERNAL STD OUTPUT," but that may
simply be a reference that is derived from the external standard, or
a backup crystal oscillator to keep the transmitter more or less on
frequency if the external reference signal is lost.)

Best regards,

Charles

Yes, i found that description and it put me off buying one. But there are
also references on the web (including time-nuts archive) to surplus T801s
with rubidium sources.

Anyway, I took a punt and bought one.
So I'll find out soon :).

On Mon, Jan 11, 2016 at 11:18 AM, Charles Steinmetz csteinmetz@yandex.com
wrote:

The T801 units I have seen in the UK contained a rubidium 10MHz reference
(FRS form factor) and a synthesizer that could produce several outputs of a
nominal 12,8MHz, but which could be individually offset slightly to allow
for precise offsetting of the transmitter frequencies by a few Hz for use
in a quasi-synch PMR system.

On 11 January 2016 at 11:18, Charles Steinmetz csteinmetz@yandex.com
wrote:

--
Stephen Tompsett

Its difficult to say unless you can contact an ex Tait dealer who maintained
a Local authority or Utility scheme. A similar unit by Pye/Philips I have
knowledge of, was the HS400. This contained a Toyocom 5MHz OCXO which was
used to lock a crystal producing the required excitation for the (analogue)
transmitter. There were two reasons for the offset, one was to avoid static
nulls were two overlapping areas had out of phase signals, and the offset
needed to be more than 20Hz (avoids flutter effects from the beats)and less
than 50Hz to avoid confusing the CTCSS decoders (tone squelch).

However later Tait gear in the 800 series was synthersized, I believe, so
this may be an stable reference source (OCXO or Rb) which could be daisy
chained to all the channel transmitters in the site. Rubidium is not
strictly necessary but was being installed in the 90s in some Police
systems. In fact the Rapco GPSDOs available on eBay some couple of years ago
came out, I believe, of London's Met Police system when they went digital.

Alan
G3NYK

----- Original Message -----
From: "Adrian Godwin" artgodwin@gmail.com
To: "Discussion of precise time and frequency measurement"
time-nuts@febo.com
Sent: Monday, January 11, 2016 1:11 PM
Subject: Re: [time-nuts] Tait reference