Clansman VRC-354 - UK Vintage Radio Repair and Restoration Discussion Forum

trh01uk · 22nd Nov 2018, 11:21 pm

No - the title isn't a typo! I do have a VRC-354. At least that's what the label on the front says.

It looks just like the VRC-353, VHF CLansman radio. I bought it as a "curiosity".

Before I investigate by opening it up - does anyone happen to know anything about this set?

Richard

M0SOE_Bruce · 23rd Nov 2018, 7:26 am

It's part of the Bowman family of radios. A 5W VHF portable.
http://www.armaholic.com/page.php?id=18280

trh01uk · 23rd Nov 2018, 9:25 am

Bruce,

well that's a very interesting reply- thanks. But I don't think its correct. Firstly my radio is not a "PRC....." its a "VRC......" And it has the size and weight to go with it. The idea that someone might like to walk about with this lump on their backs is well.......unlikely !

It looks like a VRC-353 - and for anyone who knows that radio, they will know its definitely not like the PRC-355 (?) that you are suggesting. That radio goes on a radio table (typically) - in the back of a Landrover. Here's a pic of a typical installation including 2 x VRC-353: https://armyradio.com/Clansman-Radios/

Obviously I need to get some pics of my set, and upload them to avoid any confusion as to what it is I am asking about!

Richard

M0SOE_Bruce · 23rd Nov 2018, 9:57 am

Oh yes I can see the difference one letter can make, V not P

pics would be nice. Does it cover same freq range?

I wonder if it is a 353 with an added package much like the 351/352?

There was chatter about a 353Z ( for BID250 crypto) being renamed 354 but don't know anything further.

Sparky67 · 23rd Nov 2018, 4:12 pm

Ref Bruce's comment and if it's of any help Richard there are User Handbooks mentioning the VRC353Z on eBay (lrseries-surplus shop) and the L.R. Series web sites at the moment. One has mention of the secure speech harness on the cover, the other the teleprinter T100R.
Martin
G4NCE

trh01uk · 29th Nov 2018, 10:20 am

I received a PM from Andy Jackson, G8JAC, on this subject, and he is happy for me to copy it here to put this mystery to bed:

"The answer to your question is that the original plan for the Clansman 50W VHF vehicle set was to have separate sets for voice (VRC-353) and data purposes (VRC-354) resulting in similar looking but functionally different sets. By the early ‘70s it was decided to combine the voice and data functions into one set and the VRC-354 was then abandoned as no longer needed.

The VRC-353Z is a VRC-353 + BID-250 to give an encrypted secure voice facility.

Marconi (MSDS) also designed an all-transistor version of the 353 by replacing the PA valve and the valve receiver front end, but it was abandoned because the original version had been accepted by the British army (despite the stupidity of continuously running a 50W PA even if only 100mW output was required) and sales to other countries was also taking off. At least one of the all-transistor prototypes is known to have survived intact."

I then asked Andy the following questions: "Do you happen to know at what stage the the VRC-354 was abandoned? At the trials stage? Or did some actually go into service - so the set I have might actually have been issued? Presumably there are no EMERs for the set?"

Andy's reply to that was:

"The abandonment seems to have happened around 1975 so that would have been at the trials or C-model stage but certainly before the main army roll-out with Clansman.

A description of the VRC-354 appears in the October 1972 issue of AC61004 Reference Handbook for Clansman Radio, but that section was removed by an amendment dated April 1975.

AC70806 Signal Communications in the Army Vol 3 Amendment 2 dated October 1977 states: “The UK/VRC-354 has been ceased and its extra facilities incorporated in the UK/VRC-353”.

According to AC61004, the User Handbook (Trials edition) was “Not yet published” so an EMER is very unlikely.

The illustrations of the VRC-353 dated 1972 show a completely different ATU arrangement to the Racal TUAAM and ARFAT combination that it ended up being issued with, which was a bodge in reality with the ARFAT acting as an attenuator to reduce the RF output from the VRC-353 to provide a low RF level for tuning the Racal auto ATU. The original ATU (I have one here) was intended to be tuned by data messages from the 353 rather than having the ATU match to the frequency of the transmitted signal.

For whatever reason, this system wasn’t successful so was dropped and the tune-to-the-signal system substituted. This is presumably why the 353 system ended up with a Marconi radio having a Racal antenna system."

22nd Nov 2018, 11:21 pm	#1
trh01uk Octode Join Date: Nov 2010 Location: Ross-on-Wye, Herefordshire, UK. Posts: 1,652	Clansman VRC-354 No - the title isn't a typo! I do have a VRC-354. At least that's what the label on the front says. It looks just like the VRC-353, VHF CLansman radio. I bought it as a "curiosity". Before I investigate by opening it up - does anyone happen to know anything about this set? Richard

23rd Nov 2018, 7:26 am	#2
M0SOE_Bruce Pentode Join Date: May 2013 Location: Deal, Kent, UK. Posts: 139	Re: Clansman VRC-354 It's part of the Bowman family of radios. A 5W VHF portable. http://www.armaholic.com/page.php?id=18280

23rd Nov 2018, 9:25 am	#3
trh01uk Octode Join Date: Nov 2010 Location: Ross-on-Wye, Herefordshire, UK. Posts: 1,652	Re: Clansman VRC-354 Bruce, well that's a very interesting reply- thanks. But I don't think its correct. Firstly my radio is not a "PRC....." its a "VRC......" And it has the size and weight to go with it. The idea that someone might like to walk about with this lump on their backs is well.......unlikely ! It looks like a VRC-353 - and for anyone who knows that radio, they will know its definitely not like the PRC-355 (?) that you are suggesting. That radio goes on a radio table (typically) - in the back of a Landrover. Here's a pic of a typical installation including 2 x VRC-353: https://armyradio.com/Clansman-Radios/ Obviously I need to get some pics of my set, and upload them to avoid any confusion as to what it is I am asking about! Richard

23rd Nov 2018, 9:57 am	#4
M0SOE_Bruce Pentode Join Date: May 2013 Location: Deal, Kent, UK. Posts: 139	Re: Clansman VRC-354 Oh yes I can see the difference one letter can make, V not P pics would be nice. Does it cover same freq range? I wonder if it is a 353 with an added package much like the 351/352? There was chatter about a 353Z ( for BID250 crypto) being renamed 354 but don't know anything further.

23rd Nov 2018, 4:12 pm	#5
Sparky67 Heptode Join Date: Feb 2008 Location: Great Barr, Sandwell, West Midlands, UK. Posts: 589	Re: Clansman VRC-354 Ref Bruce's comment and if it's of any help Richard there are User Handbooks mentioning the VRC353Z on eBay (lrseries-surplus shop) and the L.R. Series web sites at the moment. One has mention of the secure speech harness on the cover, the other the teleprinter T100R. Martin G4NCE

29th Nov 2018, 10:20 am	#6
trh01uk Octode Join Date: Nov 2010 Location: Ross-on-Wye, Herefordshire, UK. Posts: 1,652	Re: Clansman VRC-354 I received a PM from Andy Jackson, G8JAC, on this subject, and he is happy for me to copy it here to put this mystery to bed: "The answer to your question is that the original plan for the Clansman 50W VHF vehicle set was to have separate sets for voice (VRC-353) and data purposes (VRC-354) resulting in similar looking but functionally different sets. By the early ‘70s it was decided to combine the voice and data functions into one set and the VRC-354 was then abandoned as no longer needed. The VRC-353Z is a VRC-353 + BID-250 to give an encrypted secure voice facility. Marconi (MSDS) also designed an all-transistor version of the 353 by replacing the PA valve and the valve receiver front end, but it was abandoned because the original version had been accepted by the British army (despite the stupidity of continuously running a 50W PA even if only 100mW output was required) and sales to other countries was also taking off. At least one of the all-transistor prototypes is known to have survived intact." I then asked Andy the following questions: "Do you happen to know at what stage the the VRC-354 was abandoned? At the trials stage? Or did some actually go into service - so the set I have might actually have been issued? Presumably there are no EMERs for the set?" Andy's reply to that was: "The abandonment seems to have happened around 1975 so that would have been at the trials or C-model stage but certainly before the main army roll-out with Clansman. A description of the VRC-354 appears in the October 1972 issue of AC61004 Reference Handbook for Clansman Radio, but that section was removed by an amendment dated April 1975. AC70806 Signal Communications in the Army Vol 3 Amendment 2 dated October 1977 states: “The UK/VRC-354 has been ceased and its extra facilities incorporated in the UK/VRC-353”. According to AC61004, the User Handbook (Trials edition) was “Not yet published” so an EMER is very unlikely. The illustrations of the VRC-353 dated 1972 show a completely different ATU arrangement to the Racal TUAAM and ARFAT combination that it ended up being issued with, which was a bodge in reality with the ARFAT acting as an attenuator to reduce the RF output from the VRC-353 to provide a low RF level for tuning the Racal auto ATU. The original ATU (I have one here) was intended to be tuned by data messages from the 353 rather than having the ATU match to the frequency of the transmitted signal. For whatever reason, this system wasn’t successful so was dropped and the tune-to-the-signal system substituted. This is presumably why the 353 system ended up with a Marconi radio having a Racal antenna system."