Pump up Masts


G8ZHA
 

For my new shack, I have been thinking about getting a pump up mast, which would need to be at least 6m tall. It would need to be wall mounted and the initial payload would be an AZ & EL rotator, with a 2m and 70cm beam for satellites.

Could anyone with experiences of these masts please let me know how you get on with them. Are there any problems to look out for?

Rich  G8ZHA


g4zod@btinternet.com
 

I have a ex WD Scam mast.
It is a "temporary structure" (which has been up for 25+++ years.) It is supported by four legs with climbing steps on them.
Two fit persons can erect the mast, it is easier with three.
I have never guyed it as it stays down most of the time.
I have a 5 element 2 Metre Yagi, 14 element 70 CMs Yagi and a 14 over 14 23 CMs Yagi on a 12 ft hang glider spar.
It has coped well with this head load through many storms.
One of the  weak points of the system is that you get condensate inside and it freezes up. I tore one of the seals trying to raise the mast under icy conditions.
I had the mast jam up nearly fully extended and is was with great difficulty and a degree of brutality that I got it down.
Changing the seals is expensive, but not to difficult.
You need to drain the water out of them on a regular basis.
I have problem with a bent tube, but otherwise the mast has given good service.
You do have to treat them with a bit of respect and mechanical care.
I do not use the foot pump to elevate it but have a small air compressor.
Would I buy a new one ,the answer is yes.
PM me for further information.
Julian G4ZOD
Sent from BlueMail

On 1 Mar 2021, at 21:47, "G8ZHA via groups.io" <blueyonder.co.uk@groups.io target=_blank>g8zha-1=blueyonder.co.uk@groups.io> wrote:
For my new shack, I have been thinking about getting a pump up mast, which would need to be at least 6m tall. It would need to be wall mounted and the initial payload would be an AZ & EL rotator, with a 2m and 70cm beam for satellites.

Could anyone with experiences of these masts please let me know how you get on with them. Are there any problems to look out for?

Rich  G8ZHA


Neil Smith G4DBN
 

I have three SCAMs, well four at the moment.  While they are great, they need a lot of care. If I was getting another mast, I'd get a winch-up telescopic box section thing like a Tennamast, which wouldn't freeze up or jam in the Up position.  Total Mast Solutions do some lightweight pneumatic masts, we have one for emergency radio, but it's a similar amount of faff and more delicate than a SCAM. 

A SCAM weighs over 90kg and is a beast of a thing to shift around.  I've fitted some of mine with winches so I can luff them over to ease antenna maintenance, but they are bolted to solid buildings. Very useful if you need the antennas up at 13m, but overkill for anything lower. I have a pressurized weed sprayer with a pump handle that I fill with hot water in freezing weather to assist with de-icing, but you have to take extreme care, as things go up or come down in an indecent hurry if the seals freeze up.

Neil G4DBN

On 01/03/2021 22:19, g4zod@... via groups.io wrote:
I have a ex WD Scam mast.
It is a "temporary structure" (which has been up for 25+++ years.) It is supported by four legs with climbing steps on them.
Two fit persons can erect the mast, it is easier with three.
I have never guyed it as it stays down most of the time.
I have a 5 element 2 Metre Yagi, 14 element 70 CMs Yagi and a 14 over 14 23 CMs Yagi on a 12 ft hang glider spar.
It has coped well with this head load through many storms.
One of the  weak points of the system is that you get condensate inside and it freezes up. I tore one of the seals trying to raise the mast under icy conditions.
I had the mast jam up nearly fully extended and is was with great difficulty and a degree of brutality that I got it down.
Changing the seals is expensive, but not to difficult.
You need to drain the water out of them on a regular basis.
I have problem with a bent tube, but otherwise the mast has given good service.
You do have to treat them with a bit of respect and mechanical care.
I do not use the foot pump to elevate it but have a small air compressor.
Would I buy a new one ,the answer is yes.
PM me for further information.
Julian G4ZOD
Sent from BlueMail
On 1 Mar 2021, at 21:47, "G8ZHA via groups.io" <blueyonder.co.uk@groups.io target=_blank>g8zha-1=blueyonder.co.uk@groups.io> wrote:
For my new shack, I have been thinking about getting a pump up mast, which would need to be at least 6m tall. It would need to be wall mounted and the initial payload would be an AZ & EL rotator, with a 2m and 70cm beam for satellites.

Could anyone with experiences of these masts please let me know how you get on with them. Are there any problems to look out for?

Rich  G8ZHA
_4dbn.uk


Clive Elliott GW4MBS
 

Rich I would suggest getting a mast with a keyway, so that individual sections cannot rotate. 40 years ago I had one of the original Hilomasts it was very heavy & rotated at the base with a propeller pitch motor. At the top was a 4.5' x 6' flyswatter with elevation motor at the top. Avoid overloading it as sections may not shift then suddenly shoot up with tremendous force. This happened once & the force was so great that it blew all the mast from the lower section, the mast toppled over. I thought it was going to kill me but fell sideways bouncing off the neighbours power cables. Amazingly there was not a massive explosion!

Currently I have 3 pump ups. One is a 12m Clark which has no keyway, but the sections can be individually locked as they go up. Whether you rotate the whole thing from the base or have a smaller rotator at the top, every time you use it you will have to lock the final section so that you direction calibration is true. This is a pain especially if you find an upper section is not entirely clamped & has rotated.

I have a 9m Hilomast with keyway, this carries the 10GHz 1m dish, the rig & tilt ram so this is near the weight limit & don't forget about the weight of control cables & coax. Unfortunately it can accumulate water within the sections & during recent frost I think I have blown the seals in a top section & can't pump it up at all. Until I can repair it.

Recently I have purchase a 6m Hilomast with keyway, I have mounted at the side of the Land Rover. I need a short mast as I only want to see over modest trees & bushes, plus I needed something that would be short so as not to protrude above the roof any more that the 8m Clark PU-8 mounted on the other side (Here PU means push up, not pump up)

So pay attention to weight & choose a keyway mast. SMC now make Hilomasts these are the keyway models.

https://www.smc-comms.com/products-smc/telescopic-masts/pneumatic-masts/pneumatic-telescopic-hilomast-masts-nh-series/.
--
Clive GW4MBS (ex-G8ADP)
Pottering on 6m - 3cm in a valley in IO71XW where any QSO is a triumph of optimism over geography!


Robin Szemeti - G1YFG
 

Same here, I have a 15m Racal/Scam mast, ... I use the thickest 10m sections normally, it needs only about 5 to 10 psi max to raise it from a small compressor. Works atreat, but you do need to keeep the water drained from the sliding joints, its a git if it ices up ... they are not cheap though ...  I've seen the 15m ones go for around 900 in good condition.


On Mon, 1 Mar 2021 at 22:19, g4zod@... via groups.io <g4zod=btinternet.com@groups.io> wrote:
I have a ex WD Scam mast.
It is a "temporary structure" (which has been up for 25+++ years.) It is supported by four legs with climbing steps on them.
Two fit persons can erect the mast, it is easier with three.
I have never guyed it as it stays down most of the time.
I have a 5 element 2 Metre Yagi, 14 element 70 CMs Yagi and a 14 over 14 23 CMs Yagi on a 12 ft hang glider spar.
It has coped well with this head load through many storms.
One of the  weak points of the system is that you get condensate inside and it freezes up. I tore one of the seals trying to raise the mast under icy conditions.
I had the mast jam up nearly fully extended and is was with great difficulty and a degree of brutality that I got it down.
Changing the seals is expensive, but not to difficult.
You need to drain the water out of them on a regular basis.
I have problem with a bent tube, but otherwise the mast has given good service.
You do have to treat them with a bit of respect and mechanical care.
I do not use the foot pump to elevate it but have a small air compressor.
Would I buy a new one ,the answer is yes.
PM me for further information.
Julian G4ZOD
Sent from BlueMail
On 1 Mar 2021, at 21:47, "G8ZHA via groups.io" <blueyonder.co.uk@groups.io target=_blank>g8zha-1=blueyonder.co.uk@groups.io> wrote:
For my new shack, I have been thinking about getting a pump up mast, which would need to be at least 6m tall. It would need to be wall mounted and the initial payload would be an AZ & EL rotator, with a 2m and 70cm beam for satellites.

Could anyone with experiences of these masts please let me know how you get on with them. Are there any problems to look out for?

Rich  G8ZHA


--
Robin Szemeti - G1YFG


g1sdx
 

Hi  Rich 

Had a few  pump up masts  and if you are putting a rotator on top you will 1 need to be able to lock the sections   and 2  to be able to take a decent headload.

Scam 12  is good as can lock them off  but is a big beast  , seals   can be an issue and sections   with freezing  up as you get water in them often  but a great mast 

I have   have Rachal  40ft  mast  which is a lot more light duty and locks off  so is great   and in fact i have my  g-5500 7 turn helix 70cms es  6 ele X quad 2m on it no problems 

I also have a MTP 100 mast  which takes 50kg headload np   which is a great peace of kit .

When buying make sure is not bent of course and seals are  good with no leaks   and you can " lock the sections in some way " 



73 de G1SDX 

On Mon, 1 Mar 2021 at 22:47, Clive Elliott GW4MBS via groups.io <humber1ton=btinternet.com@groups.io> wrote:
Rich I would suggest getting a mast with a keyway, so that individual sections cannot rotate. 40 years ago I had one of the original Hilomasts it was very heavy & rotated at the base with a propeller pitch motor. At the top was a 4.5' x 6' flyswatter with elevation motor at the top. Avoid overloading it as sections may not shift then suddenly shoot up with tremendous force. This happened once & the force was so great that it blew all the mast from the lower section, the mast toppled over. I thought it was going to kill me but fell sideways bouncing off the neighbours power cables. Amazingly there was not a massive explosion!

Currently I have 3 pump ups. One is a 12m Clark which has no keyway, but the sections can be individually locked as they go up. Whether you rotate the whole thing from the base or have a smaller rotator at the top, every time you use it you will have to lock the final section so that you direction calibration is true. This is a pain especially if you find an upper section is not entirely clamped & has rotated.

I have a 9m Hilomast with keyway, this carries the 10GHz 1m dish, the rig & tilt ram so this is near the weight limit & don't forget about the weight of control cables & coax. Unfortunately it can accumulate water within the sections & during recent frost I think I have blown the seals in a top section & can't pump it up at all. Until I can repair it.

Recently I have purchase a 6m Hilomast with keyway, I have mounted at the side of the Land Rover. I need a short mast as I only want to see over modest trees & bushes, plus I needed something that would be short so as not to protrude above the roof any more that the 8m Clark PU-8 mounted on the other side (Here PU means push up, not pump up)

So pay attention to weight & choose a keyway mast. SMC now make Hilomasts these are the keyway models.

https://www.smc-comms.com/products-smc/telescopic-masts/pneumatic-masts/pneumatic-telescopic-hilomast-masts-nh-series/.
--
Clive GW4MBS (ex-G8ADP)
Pottering on 6m - 3cm in a valley in IO71XW where any QSO is a triumph of optimism over geography!



--
Regards
Grant 


ian hope (2E0IJH)
 

Scam's are great mast's but heavy, but you can get caught with a lemon if been stored incorrectly or unused for a long time. Fairly easy to rebuild but have deep pockets for the seal kit and don't forget to ask specificly for Alan Jackson when you ring Clarks and make sure you give him your callsign, Prices change when Alan knows your an amateur.
Watch for cracked or bent tubes, Geoff at Ibex films does have some tubes left from when he refurbished masts, Drain often and ensure the tubes greased often to stop them freezing, but use silicon grease
 
Ian
M5IJH

 
 
Sent: Monday, March 01, 2021 at 11:04 PM
From: "g1sdx" <g1sdxgrant21@...>
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Pump up Masts
Hi  Rich 
 
Had a few  pump up masts  and if you are putting a rotator on top you will 1 need to be able to lock the sections   and 2  to be able to take a decent headload.
 
Scam 12  is good as can lock them off  but is a big beast  , seals   can be an issue and sections   with freezing  up as you get water in them often  but a great mast 
 
I have   have Rachal  40ft  mast  which is a lot more light duty and locks off  so is great   and in fact i have my  g-5500 7 turn helix 70cms es  6 ele X quad 2m on it no problems 
 
I also have a MTP 100 mast  which takes 50kg headload np   which is a great peace of kit .
 
When buying make sure is not bent of course and seals are  good with no leaks   and you can " lock the sections in some way " 
 
 
 
73 de G1SDX 
 
On Mon, 1 Mar 2021 at 22:47, Clive Elliott GW4MBS via groups.io <humber1ton=btinternet.com@groups.io> wrote:
Rich I would suggest getting a mast with a keyway, so that individual sections cannot rotate. 40 years ago I had one of the original Hilomasts it was very heavy & rotated at the base with a propeller pitch motor. At the top was a 4.5' x 6' flyswatter with elevation motor at the top. Avoid overloading it as sections may not shift then suddenly shoot up with tremendous force. This happened once & the force was so great that it blew all the mast from the lower section, the mast toppled over. I thought it was going to kill me but fell sideways bouncing off the neighbours power cables. Amazingly there was not a massive explosion!

Currently I have 3 pump ups. One is a 12m Clark which has no keyway, but the sections can be individually locked as they go up. Whether you rotate the whole thing from the base or have a smaller rotator at the top, every time you use it you will have to lock the final section so that you direction calibration is true. This is a pain especially if you find an upper section is not entirely clamped & has rotated.

I have a 9m Hilomast with keyway, this carries the 10GHz 1m dish, the rig & tilt ram so this is near the weight limit & don't forget about the weight of control cables & coax. Unfortunately it can accumulate water within the sections & during recent frost I think I have blown the seals in a top section & can't pump it up at all. Until I can repair it.

Recently I have purchase a 6m Hilomast with keyway, I have mounted at the side of the Land Rover. I need a short mast as I only want to see over modest trees & bushes, plus I needed something that would be short so as not to protrude above the roof any more that the 8m Clark PU-8 mounted on the other side (Here PU means push up, not pump up)

So pay attention to weight & choose a keyway mast. SMC now make Hilomasts these are the keyway models.

https://www.smc-comms.com/products-smc/telescopic-masts/pneumatic-masts/pneumatic-telescopic-hilomast-masts-nh-series/.
--
Clive GW4MBS (ex-G8ADP)
Pottering on 6m - 3cm in a valley in IO71XW where any QSO is a triumph of optimism over geography!

 

 

 
 
--
Regards
Grant 


Neil Smith G4DBN
 

With the 1m dish on this SCAM, I'm hearing DB0MU beacon at decent strength at the moment on 10 GHz from 591 km.

My SCAM has alignment pins that work very well and I don't have to lock off the sections.  Might be different with a long yagi.

Neil G4DBN

On 01/03/2021


John Fell
 

Some good operational feedback here .

If the new mast is to be used in a permanent , non/P , location , consider a winch over (luffable) and winch up fixed mast .Base mount if possible , to avoid any tricky Insurance issues if it ever pulls the end wall out due to "over enthusiasm" ....

At some point you will want to add some item at the head that pushes the vertical loading specification to the limit - that is what AR experimentation does .

Having a mast up that has jammed , with the onset of an unexpected Gale and all that expensive RF hardware where you cannot get at it , is fraught  .

Yes , I have an ex Mil Clarke in the garage and it will stay there now .Nothing wrong with the construction , other than those experienced on this Forum.

My one concession to my 40 year olde , winchable 2 section , 30Ft Western Ultimast  , has been to upsize the winch cable and after the second original spec winch failed was to fit a winch with a longer handle and intermediate gearing .One big advantage is to have the maximum forces on the combined Luff and raise operation occur when the mast is approaching horizontal - a suitable prop under the head prevents the final crunch .... even then the twanging of individual wires in the rope give good audio/visual warning before it fails .

73
John
G0API

On Mon, 1 Mar 2021 at 22:47, Clive Elliott GW4MBS via groups.io <humber1ton=btinternet.com@groups.io> wrote:
Rich I would suggest getting a mast with a keyway, so that individual sections cannot rotate. 40 years ago I had one of the original Hilomasts it was very heavy & rotated at the base with a propeller pitch motor. At the top was a 4.5' x 6' flyswatter with elevation motor at the top. Avoid overloading it as sections may not shift then suddenly shoot up with tremendous force. This happened once & the force was so great that it blew all the mast from the lower section, the mast toppled over. I thought it was going to kill me but fell sideways bouncing off the neighbours power cables. Amazingly there was not a massive explosion!

Currently I have 3 pump ups. One is a 12m Clark which has no keyway, but the sections can be individually locked as they go up. Whether you rotate the whole thing from the base or have a smaller rotator at the top, every time you use it you will have to lock the final section so that you direction calibration is true. This is a pain especially if you find an upper section is not entirely clamped & has rotated.

I have a 9m Hilomast with keyway, this carries the 10GHz 1m dish, the rig & tilt ram so this is near the weight limit & don't forget about the weight of control cables & coax. Unfortunately it can accumulate water within the sections & during recent frost I think I have blown the seals in a top section & can't pump it up at all. Until I can repair it.

Recently I have purchase a 6m Hilomast with keyway, I have mounted at the side of the Land Rover. I need a short mast as I only want to see over modest trees & bushes, plus I needed something that would be short so as not to protrude above the roof any more that the 8m Clark PU-8 mounted on the other side (Here PU means push up, not pump up)

So pay attention to weight & choose a keyway mast. SMC now make Hilomasts these are the keyway models.

https://www.smc-comms.com/products-smc/telescopic-masts/pneumatic-masts/pneumatic-telescopic-hilomast-masts-nh-series/.
--
Clive GW4MBS (ex-G8ADP)
Pottering on 6m - 3cm in a valley in IO71XW where any QSO is a triumph of optimism over geography!


Mike Willis
 

I have a robust 9m pump up mast, brand new that I am unlikely to use now. It was supposed to mount on a vehicle but no reason it can't be used fixed.
--
Mike G0MJW


Clive Elliott GW4MBS
 

Mike if it is a Hilomast NH9 I would be very interested. That is what I have for the 1m dish, but until I can repair it I can't do much on 3cm. Once repaired then I want to use it to replace the 12M Clark that has no keyway.

(I can't find a private message option)
--
Clive GW4MBS (ex-G8ADP)
Pottering on 6m - 3cm in a valley in IO71XW where any QSO is a triumph of optimism over geography!


G8ZHA
 

Thanks for all the replies about the pump up masts. Could I ask about mounting them on a wall.

The attached pic shows the rear of my new shack. The corner is built from 440 * 210 * 100 concrete blocks laid flat on their side, all the way up. However, the rest of the wall is only a single skin of these blocks laid conventionally. I would like to attach the mast to the rear corner, nearest the camera.

I think the big Scam masts will be a bit out of my price range so I will take a look at the smaller light weight end of the market. If I can get up 6-7m I would be happy with that initially. It would help gauge the reactions from people who live around here as well.

Thanks for all your comments. Rich


G8ZHA
 

Could I ask.....do you leave the masts pumped up for extended periods?

Rich


ian hope (2E0IJH)
 

My scams yes, as you can lock the sections off
 
Ian
M5IJH

 
 
Sent: Tuesday, March 02, 2021 at 6:07 PM
From: "G8ZHA via groups.io" <g8zha-1@...>
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Pump up Masts
Could I ask.....do you leave the masts pumped up for extended periods?

Rich





 


Clive Elliott GW4MBS
 

Rich I retract mine when not in use that is the Hilomasts NH6 & NH9 and Clark 12m (not a as robust as SCAM)
--
Clive GW4MBS (ex-G8ADP)
Pottering on 6m - 3cm in a valley in IO71XW where any QSO is a triumph of optimism over geography!


g4zod@btinternet.com
 

My first mast ( which was an Aluminium scaffold pole + 12 ft hang glider spar)  was fixed to a single brick garage wall. However I put reinforcing plates on both sides of wall where the fixing bolts went through. The mast, rotator and three yagis survived ten years of storms.
I must add that they were modest sized antennas.
Julian G4ZOD
Sent from BlueMail

On 2 Mar 2021, at 17:23, "G8ZHA via groups.io" <blueyonder.co.uk@groups.io target=_blank>g8zha-1=blueyonder.co.uk@groups.io> wrote:
Thanks for all the replies about the pump up masts. Could I ask about mounting them on a wall.

The attached pic shows the rear of my new shack. The corner is built from 440 * 210 * 100 concrete blocks laid flat on their side, all the way up. However, the rest of the wall is only a single skin of these blocks laid conventionally. I would like to attach the mast to the rear corner, nearest the camera.

I think the big Scam masts will be a bit out of my price range so I will take a look at the smaller light weight end of the market. If I can get up 6-7m I would be happy with that initially. It would help gauge the reactions from people who live around here as well.

Thanks for all your comments. Rich






G8ZHA
 

Another mast related question.

 

When a pump up mast is used on a outside broadcast van, for instance, the coax is wrapped around the mast and when the mast is lowered, the coax forms its self into a circle on the van roof.

 

I would need a coax feeder able to cope with these circular stowage actions when raising or lowering the mast.

 

What coax do people use?

 

Rich


Robin Szemeti - G1YFG
 

Normally on an OB truck, the pump up mast carries something like RG213 for a 141 MHz antenna for talkback, or something similar.  I've never seen a pump up with anything like LDF/FSJ on it ... we used to run some mast head links, with either 2.5GHz or 7GHz on them, with Sucoflex up the mast, and a PA up at the top. I can remember replacing one of the Sucoflex runs once and the price tag was similar to that of a small car.

On Tue, 2 Mar 2021 at 23:17, G8ZHA via groups.io <g8zha-1=blueyonder.co.uk@groups.io> wrote:

Another mast related question.

 

When a pump up mast is used on a outside broadcast van, for instance, the coax is wrapped around the mast and when the mast is lowered, the coax forms its self into a circle on the van roof.

 

I would need a coax feeder able to cope with these circular stowage actions when raising or lowering the mast.

 

What coax do people use?

 

Rich


--
Robin Szemeti - G1YFG


Mike Willis
 

This is what it looks like, still in its packing crate with the compressor. It has CCTV and power cable inside.

 
--
Mike G0MJW


Mike Willis
 

After some googling it looks very much like it is one of these with the compressor and valve accessories

http://www.nrentech.com/pneumatic-telescopic-mast/9m-SecurityCCTV-PneumaticTelescopicMast

--
Mike G0MJW