Pump-up mast fitted

[radiogareth]

OK, not quite up to the 'OB Van' ease of use but its MY OB solution 10m HiLo (SMC brand I think) mast with 12V pump and solenoid air release, attached here to a drive-on plate with front/back tilt-over facility. Currently triangulated onto the van gutter, but it is a 39 year old gutter (with signs of rust...) so I'm going to add guy-rings up the mast. Might make the whole thing rotatable (once guyed) as that will reduce the head-load significantly.

Next task is to do an engine and gearbox swap to something more modern and fuel-compatible. The old slant-4 SOHC 2.3 is neither powerful nor fuel-efficient nor unleaded compatible and the gearbox has long since lost any syncro on 2nd and 3rd. Planning a 1.8 Mazda MX5 with 5 speed manual. Then it needs some power assistance for the steering electric conversions possible in exchange for £600.

Anyone else care to share their experience with pump-ups?

My rotators are all KR-400 types, biggest beam likely to be a 4 element on 6, 5 element on 4, 8 element on 2 etc upwards....and maybe some sort of dish ....
Is there any need for such height if already on a hill-top? I have a much lighter mast system (multiples of 2.0m) that is much less likely to stress the gutter...and can be used on my car in a similar way (e.g. contest photos in the last CQ-TV).

Comments welcome.....

Gareth

10_m_pump-up.jpg (115.97 KiB) Viewed 4555 times

[g8lce]

Just be a bit careful with the safety of the aerial fixing to the mast. When we used pump up masts at BBC outside broadcasts the aerials had wire retainers because there were odd cases where the mast would stick partway up until the pressure was enough to shoot it the rest of the way up. This could launch a sizeable aerial into the sky!
When I get around to mounting my pump up mast I will use some suckers, designed for lifting panes of glass, to attach a support to the glass roof of my car. The drive over plate will be the same.

Martin G8LCE

[radiogareth]

Thanks Martin, a valid point as I found when I test-inflated it - if a section shot up and topped out it was sufficient to make the whole mast jump up a few cms! I might add as locking pin into the base plate support to prevent that.
Gareth

[g8gtz]

Is there any need for such height if already on a hill-top?

Good question - I used to be the subject of some humour because I never did put my pump up mast up to the full extent as because I found when you are on a hilltop, you only need to clear local obstructions.

The exception was on 4 and 6mt where antenna height above ground is more important due to the wavelengths involved.

Even then I found 20ft or 6mts was more than adequate - and is what my current none pup system achieves.

And yes, I did also experience the struck section problem - quite scary!

73
Noel

[M5TXJ]

Gareth,

I'm sure you could add power steering far cheaper. The rally men use the steering column from a Corsa C with the electric assist motor, you need the ECU too, as well as a unit that's available to adjust the amount of assist (that's because you wouldn't have speed data available). Here's a Youtube video of someone doing this on a VW.

https://youtu.be/vq0E4Mkkda8

73 Dave

[radiogareth]

Hi Dave, Yes, 'by chance' I have just such a Corsa unit in my pile of parts, the £600 refers to the buy-in cost of such a unit already built into my column. Its within my plans to DIY but its a 'time' issue. I don't mind it as-is, but if my wife is to drive it she doesn't fancy wrestling with it!
I've got to un-pick the original donor engine loom and identify the parts needed to make it run, set it all back up and then do the engine swap. All things I've done previously, but all sorts of fun radio/DATV stuff keeps distracting me too
Gareth