Showing posts with label Clansman. Show all posts
Showing posts with label Clansman. Show all posts

Saturday, March 03, 2018

A troublesome trio

If you read my previous entry you may remember that I was debating whether to put my R1155 or my WS19 at the front of the restoration queue. I had almost decided to concentrate on the WS19, as it appeared require less work to return to working condition, but then three unexpected and more urgent jobs arrived... all of them HF transceivers!

Clansman RT320,  PSU module removed




 My Clansman RT-320 developed a (nasty) power supply fault


Yaesu FT-757GX

                              My Yaesu FT-757GX had frequency stability problems

Alinco DX-70TH







And finally my Alinco DX-70TH failed
with a duff PA driver transistor!





I was able to start investigating the WS19 power supply while waiting for the Alinco's transistors to arrive. By late in February with all three troublesome radios working again, I was finally able to clear the bench and turn my attention back to restoration work.

More details will follow soon.

Keep listening!


Sunday, July 20, 2014

Clansman military radios

Clansman was the name given to a Combat Radio System used by the UK armed forces from the late '70s to around 2009, when it was replaced by the current Bowman system. It comprised a range of man portable and vehicle mounted radios in the HF (2 - 30MHz), VHF (30 - 76MHz) and UHF (225 - 400MHz) frequency bands.

The HF and VHF versions are of interest to radio amateurs for the HF, 6M and 4M bands and are becoming very collectable. The UHF kit is AM only, and has no real amateur radio application. Disposals by the Ministry of Defence have now ceased and inevitably the price of available kit has begun to rise significantly. 

I acquired my first Clansman radio, a PRC320 HF man-pack, around a year ago. It's an excellent piece of kit, although it is heavy and somewhat basic compared to commercial and amateur transceivers. It is however extremely rugged and can be thrown around, used in the pouring rain or have beer spilled on it without suffering any damage.

A PRC320 similar to mine, with whip antenna connected.
The PRC320 was primarily designed as a man portable radio but it could also be installed into vehicles. The original military uses were to provide ground wave communications over short distances using either the whip antenna or an end-fed vertical, or sky wave communications over greater distances using a dipole.

The built in Antenna Tuning Unit is somewhat limited and will only work with the whip or end fed wire antenna. Dipole antennas are assumed to be resonant on the frequency in use; these are connected directly to the transceiver, bypassing the built in ATU.

My 320 in fixed-station use during a recent camping trip

For amateur radio an external ATU (in my case an MFJ-949e) is useful and will allow a wide range of antennas to be used with the PRC320. The maximum RF output is 30W, on CW, AM or USB.  One of the most common modifications is to add LSB; there are various was of doing this, most of which apparently work very well.

As with any form of electronic equipment, older examples may need a bit of work to restore reliability; some Clansman radios are 30 years old, and even military grade components can degrade in this time! To a fan of radio restoration, this is part of the fun in owning kit like this.

There are a number of excellent websites and user forums covering repair, modification and use of Clansman radios, so I won't add to them here. I have come up with a couple of modification ideas of my own, so these will get blogged later.

Keep listening!