UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Amateur and Military Radio

Notices

Vintage Amateur and Military Radio Amateur/military receivers and transmitters, morse, and any other related vintage comms equipment.

Closed Thread
 
Thread Tools
Old 13th Jan 2022, 4:11 pm   #1
sparkymike
Octode
 
Join Date: Dec 2006
Location: Colchester, Essex, UK.
Posts: 1,063
Default Ex-army antenna mast info needed.

I have bought an ex army six section telescopic antenna mast for my forthcoming radio shack. Goes up around 30 feet or so. It is air powered and I have a compressor here, but no information on what air pressure psi I need to raise the thing. Obviously I don't want to put too much air in it, as I can visualise the top section parting from the rest of the mast like a space rocket and ending up in someone's greenhouse!!

It is the sort of mast that the army used in their radio trucks I believe but I can't find any info on the net as yet. I also believe there should be a restrictor valve of some kind, for the air pressure, so that it would be impossible to over-inflate.

Mike
sparkymike is offline  
Old 13th Jan 2022, 4:57 pm   #2
McMurdo
Dekatron
 
McMurdo's Avatar
 
Join Date: Jun 2009
Location: Staffordshire Moorlands, UK.
Posts: 5,263
Default Re: ex-army antenna mast info needed

In pneumatic cyclinders, a flow restrictor is used to govern the speed, and a pressure regulator governs the force. Doesn't your compressor have an adjustable regulator? Set it low and crack open the outlet valve and see what happens.
__________________
Kevin
McMurdo is offline  
Old 13th Jan 2022, 5:05 pm   #3
Guest
Guest
 
Posts: n/a
Default Re: ex-army antenna mast info needed

Clark Masts are the military favorite, here https://www.clarkmasts.com/mast-acce.../2/ab-control/ 25psi I would go for just enough to raise it and load plus 10%.
 
Old 13th Jan 2022, 5:32 pm   #4
ex 2 Base
Heptode
 
Join Date: Nov 2009
Location: Scarborough, North Yorkshire, UK.
Posts: 507
Default Re: Ex-army antenna mast info needed.

Hello Mike how about nipping down to the local army barracks and ask to speak to the Signals/ REME workshop more senior staff. I have a compressor and like Kevin says, about the regulator I can adjust the pressure on mine. So, how about starting very low PSI (or it's Bars now) and see how things go. If you are a member of RSGB I'm sure a posting in Radcom you will soon get a positive reply if not here. Ted
ex 2 Base is offline  
Old 13th Jan 2022, 5:45 pm   #5
Mr 1936
Heptode
 
Join Date: Mar 2017
Location: Romsey, Hampshire, UK.
Posts: 511
Default Re: Ex-army antenna mast info needed.

Hi Mike

As a crude calculation, if the cylinder diameter is 3 inches and the pressure is 25 PSI that would support 178 lb (80 kg)

The type I used to be involved with had a locking knob for each section, so raising it was a fairly controlled process of progressive unlocking and locking, starting with the top section. Once it's up and locked off you don't need any pressure.

Surprised you don't have a data plate, unless it's been removed or painted over.
Mr 1936 is offline  
Old 13th Jan 2022, 6:00 pm   #6
G6Tanuki
Dekatron
 
G6Tanuki's Avatar
 
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,951
Default Re: Ex-army antenna mast info needed.

The pneumatic masts I remember using back in the 70s and 80s when with the Territorial army were Clark "SCAM" [Self Contained Antenna Mast].

See here: http://www.portablemasts.com.au/Clark/clarkp17.htm

for lots of useful info!
__________________
I'm the Operator of my Pocket Calculator. -Kraftwerk.
G6Tanuki is offline  
Old 13th Jan 2022, 11:29 pm   #7
Chris R
Pentode
 
Join Date: Nov 2021
Location: Laurencekirk, Kincardineshire, Scotland, UK.
Posts: 182
Default Re: Ex-army antenna mast info needed.

Clark's masts were used extensively by the Royal Observer Corps underground posts. They used a hand pump and the pressure was therefore relatively low.

It should be noted that only silicon grease should be used when lubricating these.

Chris R
Chris R is offline  
Old 14th Jan 2022, 1:24 am   #8
bigfathairyvika
Hexode
 
bigfathairyvika's Avatar
 
Join Date: Nov 2009
Location: Cambridge, Cambridgeshire, UK.
Posts: 489
Default Re: Ex-army antenna mast info needed.

I spoke to the technical support at Clark Masts who say to use any engine oil for scam 12 mast lubrication.

Last edited by bigfathairyvika; 14th Jan 2022 at 1:34 am.
bigfathairyvika is offline  
Old 14th Jan 2022, 10:05 am   #9
sparkymike
Octode
 
Join Date: Dec 2006
Location: Colchester, Essex, UK.
Posts: 1,063
Default Re: Ex-army antenna mast info needed.

I have a spray gun regulator that I can try. The mast looks very similar to the one pictured in the last link without the stand and the other extra items. I was thinking around 15 psi, so will take it easily.
Mike.
sparkymike is offline  
Old 14th Jan 2022, 3:09 pm   #10
Chris R
Pentode
 
Join Date: Nov 2021
Location: Laurencekirk, Kincardineshire, Scotland, UK.
Posts: 182
Default Re: Ex-army antenna mast info needed.

I should have said that I was referring to the 30' masts. The Clark maintenance instructions definitely said silicone grease. Interesting to note that they use engine oil on Scam masts. Perhaps they have changed the formulation of the seals.

We carried a good stock of the 30' seals. Some of the 'customers' thought that they were being helpful by doing DIY servicing and used normal grease. This resulted in the seals swelling and jamming the mast. Units were always stored vertically, to avoid the distortion of the seals when laid on their sides.
Masts installed on vehicles did use a 12v compressor - it took an age to pump them up.
The larger trailer masts were taken to Clark's for service. They also had an on board compressor.
One interesting occurrence happened when a 100' version was left extended for a long period. Trying to get it to come down again proved to be difficult.

Chris R
Chris R is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 8:48 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.