Wanted: Person who can explain a Clansman part

[radiozero]

I'd like someone with a technical understanding of the Clansman radio system to explain how a part of the system works.

I'm hoping you might have on hand a relevant circuit diagram, and might be willing to tell me where I can get it.

I await responses. :c)

Rich

[wave solder]

There are an awful lot of "bricks" making up a Clansman installation, which particular part are you enquiring about?

[Sean Williams]

Some indication of which area of Clansman you are interested in might help - I have a fair number of documents relating to the system.

However, if you are referring to the encrypted BID parts, then good luck, information is very scarce (with good reason!)

[ex seismic]

Come on, give us all a clue! Which radio or are we talking vehicle installations and intercoms?

Gordon

[radiozero]

OK, it's a BCC-543 .

[Stockden]

Ah, so you mean the TN402 TUAAM?

There's a short description of its purpose in the article here and a bit more technical detail here

[radiozero]

I'd love to get a circuit diagram, but I think that a circuit is not easily obtained. That is my impression - after searching the internet. If I have to, I'll trace out the circuit over the next few months. See if I can cobble together an understanding of how TN/402 BCC-543 works. Unless anyone else wants to figure the circuit.

Rich

[Sparky67]

BCC543 Clansman TUAAM Operation

ARFAT - Attenuator Radio Frequency Antenna Tuning
TUAAM - Tuning Unit Automatic Antenna Matching

The ARFAT is connected to the 353 via a 12W connector (5 ways used) and a 50 Ohm coaxial cable.
The TUAAM is connected to the ARFAT via a 7 way connector (4 ways used) and a 50 Ohm coaxial cable.

12W connector on ARFAT from 353...or clip-in manpack adaptor:

Pin S - +28VDC i/p from 353
Pin M - keyline to Tx - low impedance to key transmitter.
Pin P - OV
Pin L - Tx inhibit - temp sensed in ARFAT and sent to 353. 'Nearly OV'.
Pin O - Silent tune from 353 - active low - activates 50 Ohm load in TUAAM 7W connector from ARFAT to TUAAM (ARFAT connector pinout shown)
Pin C - +28VDC from 353 via ARFAT
Pin F - Keyline to 353 via ARFAT - active low
Pin E - OV
Pin B - Silent tune i/p to TUAAM from 353 - active low ~~~ Initial application or an interruption of the 28V supply causes the TUAAM to start its tuning sequence.

I have no information on how long the interruption needs to be but I would suggest it is fairly short to operate the TUAAM's latch. The TUAAM then keys the radio via the low-going keyline.
The keyline also causes the ARFAT to insert a 10dB pad in the RF path through the ARFAT. +20V is also applied to the coax centre - sent back to the 352 when in 'clip-in' role to inhibit use.
Low-level RF applied to the TUAAM is then routed to a sequence of staged impedance matching devices.
The matching of these is monitored by disriminators and detectors within the TUAAM and when a minimum VSWR is detected, tuning is completed the keyline output returns to high impedance - and the 10dB pad is removed in the ARFAT - and the +20v is removed from the coax inner.

Silent tune is effected by applying OV to the 'Silent Tune' line. This operates a relay in the TUAAM which applies a 50 Ohm load to the output normally connected to the antenna.

The ARFAT takes 400mA and the TUAAM 250mA when tuning and 2.5mA quiescent, and operates between 21 and 35VDC. The TUAAM requires 3 - 5W for tuning and handles 1 - 75W when tuned. It tunes within 5 seconds. Insertion loss is better than 1.5dB.

Hope this helps.

[radiozero]

Originally Posted by Sparky67

I posted a description of how it works on the Yahoo Clansman-Larkspur group...copied below.
[....]
Hope this helps.

Hi. Thanks. I'm pleasantly messing about with this unit. I'm curious. My investigations need some priming and I think you have provided it. Much obliged. Rich

[Station X]

One post edited at poster's request.