Antenna base - between spring and vehicle

[Doddy]

Hi Diana,

I was not aware of that problem.

I cannot talk about breaking nice new 3 band aerials on trees.

Watching developments with interest

I could use one also

Peter

[sydneymver]

Please add my name to the interested parties list.

following with interest.

Bruce McCann

[Doddy]

The bases still turn up occasionally on evilbay

Found this one while looking at other things

No connection with seller but has a good feedback score

http://www.ebay.com.au/itm/NEW-MILITARY-RADIO-MX-6707-VRC-Vehicle-Antenna-Mast-Base-/271526497063?pt=LH_DefaultDomain_0&hash=item3f383d8b27

Doddy

[Diana Alan]

I didn't get to the fibreglass place till this week (its on the other side of Sydney).

They will make a mould for about $150 and say that each mount will cost about $100 (seems expensive to me)

Also they suggested a tube in the middle to make it smooth (I didn't mention it at that point) we then discussed the strength and their advice was making up a washer connected to the tube.

Have now had a chat with an welder/engineer who specialises in alloy and stainless about getting the disks laser cut and welding them to alloy tubes.  Last time I has things laser cut each item was about $10 that would have to be $15 by now.

So I cant see the finished product costing less than $150 each (without adding the cost of the mould).

Im sure this will make people's interest wain.

[Minikeg]

Last time I has things laser cut each item was about $10 that would have to be $15 by now.

I think its time to find a new lasercutter personally..?? When asking for product, a top tip is to say you arent in a hurry and to throw it on next time they are running that material - my local lasercutter cuts most materials/thicknesses at least once each week and if I paid more than $2 for 'discs' of metal Id be surprised. Unless the discs are frisbee sized..?

Id offer to quote but shipping metal from newcastle sounds expensive. Still, may keep the sydney blokes honest?

[Diana Alan]

Happy to use anyone if we get a good price.

All we need is 70mm circles with a 16mm concentric hole in the middle made out of something like 6mm aluminium (or stainless) we can go thinner but wouldn't want to go less than 4mm.

a 3Kg post pack satchel only costs about $10

Im hoping to get some off cut tubes when a set of hood bows for a TLC are made, the tubes were tent poles from a 20 X 20 or something larger.

How critical do we want to be for height etc.  The original plastic bit had a 9.5mm plate on the top which the spring base mounted to and there was a 3mm housing underneath.  If we want to be accurate and use 6mm plate on the top, I'll have to add 3.5mm to the plastic part to get the mould correct height.  The same with the base.  Are we that fussy?

Also there us usually a cover flange (a bit like a big dished washer) that sits on top of the mounting before the bolts are inserted to hold everything down.  Do we also want to go that far?

[Minikeg]

Happy to use anyone if we get a good price.

All we need is 70mm circles with a 16mm concentric hole in the middle made out of something like 6mm aluminium

Had no idea of quantity, so just asked for 10 & 20

6mm aluminium 70mm circle / 16mm hole
$7ea for 10 / $6.40 for 20

6mm mild steel (had already asked for a mild steel quote before stainless was added)
$5.12 for 10 / $4.64 for 20

which yeh, isnt $2.. but hey, it aint $15 either

[Diana Alan]

I don't think $6.40 is too bad, but with the other costs we're getting close to a grand for a batch of ten, and being burnt with making batches of things before I think I'll start at ten.

PM me your bank details and I'll deposit the dollars.

6mm aluminium, then we don't have rust problems.

[Minikeg]

Ill send you the invoice, which will have their bank details on it and you can pay them directly; itll take a week anyway so there isnt a hurry

With the tube, Ive had success with these guys making a hole to exactly fit a supplied tube, so that it was 'jammed' in and was never going to come out again - is this what you are after? If so, is 16mm the /exact/ size? Just so that I have not interpreted something entirely wrong, could you sketch a rough pic with the required dimensions, just so nothing is lost in translation?

Email me at scott@trout-slap.com

Is there anything else requiring cutting to do with this project?

[Diana Alan]

Hi Scott

The centre hole is for the antenna, the design is now that the tube will be large enough to allow the antenna nut and a tube spanner to be inserted from the bottom, so it will be about 35mm ID.  The tube will be welded to the bottom of the plate and that assembly placed in the mould before the glass/resin is inserted.

Diana

[xplore]

Hi Diana, can you tell me how to dismantle the upper section or the section just below the antenna spring so as i can convert to a uhf installation….thanks Gaz.

[Diana Alan]

Hi Diana, can you tell me how to dismantle the upper section or the section just below the antenna spring so as i can convert to a uhf installation….thanks Gaz.

Hi Gaz

It's not as simple as one would hope and will likely break the plastic base when you remove the contents of the ATU.

You basically undo the screws on the top and the bottom, there are a second lot of screws in the alloy plate below the spring.  The problem is getting the coil unit out of the housing which is a tolerance fit and where the housing will most likely fail.

I'm currently waiting for the aluminium disks to arrive in the post from Minikeg, then we can start the mount project.

[xplore]

Thanks Diana for quick reply, l'm wondering if l was to drill the centre out if this would allow for an easier removal of the tolerance fitted coil unit? might be worth a try while l wait for project.

[Diana Alan]

Its a shame to destroy an ATU merely for a CB antenna.  But it is yours to do with what you want.

If it were me I would mount a temporary plate on the bracket to hold the CB antenna until a replacement is available.

[DBT]

If it were me I would mount a temporary plate on the bracket to hold the CB antenna until a replacement is available.

... Exactly what I have done.

Not that I have an ATU to butcher, but fabricating a plate was easier.