Registry of Ex Military Land Rovers

REMLR Radio Shack => REMLR Radio Chatter => Topic started by: DBT on June 12, 2014, 09:43:26 AM

Title: Antenna base - between spring and vehicle
Post by: DBT on June 12, 2014, 09:43:26 AM
Hi all,

After some info on the metal base that bolts to the antenna brackets on the FFR (110). The bit below (and possibly including?) the antenna spring.

Are these a generic unit, or are they part of the antenna kit? Are they generally available? Do they have a name? I'm assuming (hoping) it's not a tuner, just a mount.

I plan to use 2 of my brackets to mount UHF CB and NextG antennas. Apologies to FFR restorationists for my planned butchery. :)

Thanks for any advice.

Dave.
Title: Re: Antenna base - between spring and vehicle
Post by: aussiegregmac on June 12, 2014, 10:15:09 AM
The item you talk about is the MX-6707 Ant. matching Unit.

http://www.armyradio.com/arsc/customer/product.php?productid=1637

However , not suitable for your intended use.  You'd be better off getting some flat plate with your UHF ant. spring bolted into that with the plate bolted to the steel brackets.

The Mil stuff is designed for a different Freq. range.
Nothing wrong with your intended purpose as it doesn't change anything that's there already.
Greg Mac.
Title: Re: Antenna base - between spring and vehicle
Post by: Greg & Tony Egretz on June 12, 2014, 12:24:55 PM
My son and I are gutting one to run a uhf antenna cable through it and 2.1 m uhf antenna on it. It will still look Mili spec on the outside, the only reason were doing that to it when I got  the base, sometime in it's army service it caught on fire on the inside and damage beyond repair events on the outside of the fire too.
Cheers Greg Egretz 150
Title: Re: Antenna base - between spring and vehicle
Post by: DBT on June 12, 2014, 12:46:43 PM
Many thanks Greg M and Greg E.

As i feared its a tuning unit, which i don't need.

I like your idea Greg E of using the shell to mount a UHF. It would at least look authentic, in lieu of function.

I shall keep an eye out for incomplete / unserviceable examples.

Thanks again.

Dave.
Title: Re: Antenna base - between spring and vehicle
Post by: Diana Alan on June 12, 2014, 12:59:35 PM
I might take one of the bases down to our local fibreglass auto body parts maker and see if he'll do a mould then we can just order up the positives and fit an antenna base into it.

May be able to do it tomorrow.

Fitting something like the 2.08m RFI "UHF CBRS Q-Fit Collinear 477MHz - 8 dBi"   http://www.rfiwireless.com.au/mobile-antennas/citizens-band-mobile/uhf-cbrs-q-fit-collinear-cdq8000-b.html#tab_desc (http://www.rfiwireless.com.au/mobile-antennas/citizens-band-mobile/uhf-cbrs-q-fit-collinear-cdq8000-b.html#tab_desc) would even look similar to the AS1729, particularly if we painted them khaki green.
Title: Re: Antenna base - between spring and vehicle
Post by: Mick_Marsh on June 12, 2014, 03:44:15 PM
Great idea Diana.
Put me down for a few.
Title: Re: Antenna base - between spring and vehicle
Post by: Aussie Jeepster on June 12, 2014, 06:17:30 PM
Sounds good to me too.
Title: Re: Antenna base - between spring and vehicle
Post by: Greg & Tony Egretz on June 12, 2014, 07:14:43 PM
put us down for couple as well sound like a good idea Cheers Greg Egretz 150
Title: Re: Antenna base - between spring and vehicle
Post by: DBT on June 12, 2014, 09:58:47 PM
I'll take 2 please!

:)
Title: Re: Antenna base - between spring and vehicle
Post by: Doddy on June 12, 2014, 10:34:43 PM
Hi,

I have a handbook for these antennas and tuning units if anyone needs specific info on internal components etc.

The fibre glass copy sounds like an excellent idea for mounting cb etc antennas.

Please don't gut good working examples just to mount a different antenna, as stated above they are getting harder to find.

I wonder how they managed to cause one to catch fire, as the unit is rated at 70Watts?

Regards
Doddy
Title: Re: Antenna base - between spring and vehicle
Post by: Greg & Tony Egretz on June 13, 2014, 06:52:47 AM
Hi Doddy as a sig in the army reserves  back in the 80's never had one catch on fire, but when I saw this one I tried to work how this could of happened (vehicle fire maybe?)
Cheers Greg Egretz 150
Title: Re: Antenna base - between spring and vehicle
Post by: Phoenix on June 13, 2014, 12:48:06 PM
Bushfire could have been the cause, I have photos of a few vehicles gutted by fire, particularly a set from holdsworthy of a few that were caught in a yard.
Title: Re: Antenna base - between spring and vehicle
Post by: Diana Alan on June 13, 2014, 08:34:25 PM
Missed the fibreglass mob apparently they finish early on Fridays.  I did however spend the time to dismantle one of the bases to investigate and so I have an easy sample to take the mould off.

Am also wondering about the construction.  What would people think about having the bases manufactured with an aluminium tube in the middle which is tapped to the same thread as the RFI antenna mentioned previously?  This way the antenna screws into the mount and the forces in the antenna would be distributed to the length of the tube, rather than just the very top of the mount.  Could even leave some tube protruding from the bottom so a grounding strap can be attached.
Title: Re: Antenna base - between spring and vehicle
Post by: Doddy on June 13, 2014, 09:38:14 PM
How well will the tube bond to the fibreglass?

Would it be a better idea to have a metal plate on top of the fibreglass "cone" with the 16mm mounting hole drilled in it, much like the original?
You would need tube spanner to tighten nut.
Assuming from web site literature that it is supplied with cable coming up through the base of the spring and spring has some sort of coaxial socket at the top that antenna attaches to.

Just some ideas

Doddy
Title: Re: Antenna base - between spring and vehicle
Post by: Diana Alan on June 14, 2014, 09:40:14 AM
Hi Doddy

The original MX6707 housings have a reputation for cracking just above the mounting flange, I would assume a plate in the top would have a similar problem because of the torsional effects when the tip of the antenna hits something like a tree branch.  The plate idea would also require a larger hole through the middle for the nut and tube spanner (very long tube spanner)

Will discuss the options with the fibregalss blokes this week.
Title: Re: Antenna base - between spring and vehicle
Post by: Doddy on June 14, 2014, 10:07:05 AM
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

Title: Re: Antenna base - between spring and vehicle
Post by: sydneymver on June 14, 2014, 01:37:10 PM
Please add my name to the interested parties list.

following with interest.

Bruce McCann
Title: Re: Antenna base - between spring and vehicle
Post by: Doddy on June 21, 2014, 08:23:25 AM
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
Title: Re: Antenna base - between spring and vehicle
Post by: Diana Alan on June 25, 2014, 12:53:54 PM
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.
Title: Re: Antenna base - between spring and vehicle
Post by: Minikeg on June 25, 2014, 01:11:25 PM
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?
Title: Re: Antenna base - between spring and vehicle
Post by: Diana Alan on June 25, 2014, 01:30:35 PM
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?
Title: Re: Antenna base - between spring and vehicle
Post by: Minikeg on June 25, 2014, 02:10:07 PM
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 :P
Title: Re: Antenna base - between spring and vehicle
Post by: Diana Alan on June 25, 2014, 04:15:10 PM
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.
Title: Re: Antenna base - between spring and vehicle
Post by: Minikeg on June 25, 2014, 04:31:41 PM
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?
Title: Re: Antenna base - between spring and vehicle
Post by: Diana Alan on June 25, 2014, 04:51:32 PM
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
Title: Re: Antenna base - between spring and vehicle
Post by: xplore on September 02, 2014, 07:53:04 PM
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.
Title: Re: Antenna base - between spring and vehicle
Post by: Diana Alan on September 02, 2014, 09:15:28 PM
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.
Title: Re: Antenna base - between spring and vehicle
Post by: xplore on September 02, 2014, 09:24:29 PM
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.
Title: Re: Antenna base - between spring and vehicle
Post by: Diana Alan on September 02, 2014, 10:35:03 PM
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.
Title: Re: Antenna base - between spring and vehicle
Post by: DBT on September 03, 2014, 02:02:06 AM
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.
Title: Re: Antenna base - between spring and vehicle
Post by: xplore on September 03, 2014, 07:19:51 AM
Yes l agree with you both, but it was given to me with the lower section missing and going on pics from the net it looked quiet complex so l hope l'm not upsetting anyone!!
Title: Re: Antenna base - between spring and vehicle
Post by: DBT on September 03, 2014, 08:10:44 AM
No worries Gaz. Prob not a big deal if its incomplete / unservicable.

There are a few people here who are restoring vehicles who may pay decent money for a working unit. They are not the easiest items to obtain.

Dave.
Title: Re: Antenna base - between spring and vehicle
Post by: kman on September 05, 2014, 03:41:47 PM
Those doing this may be interested in the RFI CD991-67-73 as it covers the full band from 400-520MHz. This means it can be used with virtually all Australian UHF services including Amateur, CB, SES, RFB, Police and commercial. Combined with a radio with, e.g., coverage from 430 to 480 MHz it gives a single radio solution.

Howard
Title: Re: Antenna base - between spring and vehicle
Post by: Paulak on September 10, 2014, 11:04:12 AM
Gday Diana Alan I would be interested in a look at the finished product.
Thanks. Paul.
Title: Re: Antenna base - between spring and vehicle
Post by: Carzee on September 10, 2014, 11:23:02 AM
Those doing this may be interested in the RFI CD991-67-73 as it covers the full band from 400-520MHz. This means it can be used with virtually all Australian UHF services including Amateur, CB, SES, RFB, Police and commercial. Combined with a radio with, e.g., coverage from 430 to 480 MHz it gives a single radio solution.

Howard

Hi Howard, very interesting. I just googled RFI CD991-67-73 and there is only one mention in the whole world - yours (above), 4 days ago.

"Combined with a radio with, e.g., coverage from 430 to 480 MHz it gives a single radio solution." What would be your recommended radio?
Title: Re: Antenna base - between spring and vehicle
Post by: kman on September 10, 2014, 04:19:21 PM
Yes. i emailed RFI about having another of their antennas tuned to cover frequencies I want and they came back with this one. I have now bought one and it is a solid piece of kit: it will look ok mounted on a sugar scoop.

As for radio, I think the WM9000plus ( http://www.409shop.com/409shop_product.php?id=108685 ) would meet most requirements.

Howard
Title: Re: Antenna base - between spring and vehicle
Post by: Diana Alan on September 10, 2014, 04:29:00 PM

Hi Howard, very interesting. I just googled RFI CD991-67-73 and there is only one mention in the whole world - yours (above), 4 days ago.

"Combined with a radio with, e.g., coverage from 430 to 480 MHz it gives a single radio solution." What would be your recommended radio?
Hi Carzee

The antenna is easier to find if you go direct to the RFI site and search the antenna from there ( http://www.rfiwireless.com.au/broadband-uhf-elevated-feed-antenna-cd991-67-73.html (http://www.rfiwireless.com.au/broadband-uhf-elevated-feed-antenna-cd991-67-73.html) )

The antenna however may look a little out of place against a AS1729 as its a little less than 18" long.

(http://www.rfiwireless.com.au/media/catalog/product/cache/1/image/250x/9df78eab33525d08d6e5fb8d27136e95/a/b/ababab.jpg)

The radios it would work with are:
UHF-CB,
Amateur (Ham) radios in the 70cm band
Commercial licences

Hi Paulak

Currently I am only doing a small batch because of the costs to me, about half of the 10 have been allocated.  They won't be cheap as I have been quoted about $150 just to make the mould, the alloy disks are $8, the alloy tube hasn't been costed but add a couple of dollars and then the welding and tthen there is the resin and fibreglass or the cost if they do it for me.

What I am after is the cover ring over the bottom flange of the ATU.  These will be discarded when ATU break but will cost heaps if I have to make a press mould or spin each ring individually.

Will let you know when they're finished.
Title: Re: Antenna base - between spring and vehicle
Post by: kman on September 10, 2014, 05:25:15 PM
Actually they are not selling that one now but the TYT9000 plus is identical (the WM was a rebadge)

Howard
As for radio, I think the WM9000plus ( http://www.409shop.com/409shop_product.php?id=108685 ) would meet most requirements.

Howard
Title: Re: Antenna base - between spring and vehicle
Post by: Diana Alan on September 10, 2014, 06:15:20 PM
Yes. i emailed RFI about having another of their antennas tuned to cover frequencies I want and they came back with this one. I have now bought one and it is a solid piece of kit: it will look ok mounted on a sugar scoop.

As for radio, I think the WM9000plus ( http://www.409shop.com/409shop_product.php?id=108685 ) would meet most requirements.

Howard
Hi Howard

Back in June I contacted RFI about the possibility of having the CDQ5000 or the CDQ8000 (5dbi or 8dbi gain) refinished in khaki, but they would want about 50 ordered before they even considered it.

I thought for our purposes the CDQ5000 etc, were a better option than something like the CD991-67-73 because most of our members don't have Amateur licences so an antenna tuned to the UHF CB frequences more appropriate and also that the stick is over 2m long so similar in length to the AS-1729 also with a detachable stick leaving the spring base just like on the MX-6707.

Diana

The CDQ antennae are at :
http://www.rfiwireless.com.au/mobile-antennas/citizens-band-mobile/uhf-cbrs-q-fit-collinear-cdq8000-b.html#tab_spec (http://www.rfiwireless.com.au/mobile-antennas/citizens-band-mobile/uhf-cbrs-q-fit-collinear-cdq8000-b.html#tab_spec)

(http://www.rfiwireless.com.au/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/c/d/cdq2199-b_1.png)
Title: Re: Antenna base - between spring and vehicle
Post by: kman on September 10, 2014, 08:10:21 PM
Good call Diana. In my case I use it for amateur, Rural Fire Brigade and CB.

By the way, I applied to ACMA for a frequency around 46MHz for our Club with the idea we could use ex-mil gear for club comms. Unfortunately they were willing to give us a frequency but only in VHF or UHF bands.

Howard
Title: Re: Antenna base - between spring and vehicle
Post by: gooloo on February 08, 2017, 08:22:30 PM
Dredging up an old thread.... did these bases ever get made? I want one  :)