Stealth antenna...

[DaveJacobsen]

I have a Triumph spitfire convertible that I plan on taking on a road trip/rally & I want to take a cb as that is what's being pushed as a "standard".

Trunk would be ideal, but impractical (can't open trunk, plus there is a luggage rack in the way.

I am hopeful to find a nice whip I can mount in lieu of the am/FM antenna.

Otherwise, I'll end up with a trunk lip mount and use a quick disconnect (which I hate) so I can open the trunk with the top up.

Any suggestions?

 

[K6EEN]

Hustler FG-27S (48 inches), RG-27 (36 inches), or RTS-27L (25 inches). Center-loaded "low profile" shortened antennas from Hustler.
Hustler Catalog
Some of these are available with a choice of color for the coil cover, "B" designation on the end of a model number means "black" color or black coil.

Doubt you're going to find an antenna that is a drop-in to the front fender hole for the factory FM radio in a Triumph, though. Most hole mounts for CB antennas, which tend to be long, are going to be 3/4 inch (NMO style or Hustler proprietary) or 7/8 inch (Wilson proprietary). If the existing antenna hole is 1/2 inch, you may be able to fit a standard CB 3/8x24 stud.

Modern trunk lip mounts from Japan (brands Comet or Diamond) clip on to the left or right edge of the trunk, and have swivels to make sure the antenna can be rotated to vertical no matter what the profile of the trunk or hatchback. Older-style trunk lip mounts for the center-back edge of the trunk are available from Hustler, Tram, K40, Larsen, etc.

Consider a Diamond K400 2-axis swivel trunk lip mount with either a 3/8x24 standard CB stud, or a NMO style mount. Then get a low-profile 3/8x24 center-loaded antenna like the Hustler FG-27S or RG-27, or for a better signal a longer NMO base loaded antenna such as the Larson NMO27C or Browning BR-140 or Opek HFM-410. Just keep the 3/8x24 lightly-tightened, and remove when you want to open the trunk. If you go with the NMO mount, the Larsen NMO27 whip unthreads by hand via a knurled brass fitting at the top of the coil, so you can quickly unscrew the whip to open the trunk, leaving the coil on the NMO mount.

 

[mmckenna]

Trunk would be ideal, but impractical (can't open trunk, plus there is a luggage rack in the way.

I am hopeful to find a nice whip I can mount in lieu of the am/FM antenna.

Otherwise, I'll end up with a trunk lip mount and use a quick disconnect (which I hate) so I can open the trunk with the top up.

Any suggestions?

Back in the 70's/80's, various manufacturers sold couplers that would go inbetween the AM/FM radio and antenna and allow you to connect a CB. I'm not aware of anyone still selling those, but there are sometimes some on eBay.
They don't work well, but they do work. If you only need short range, that may be a good solution.

Stico makes replacement antennas that will allow you to still use your AM/FM goodtimes radio and a transceiver, (including low band down to 25MHz), but very highly unlikely the make a specific model for your vehicle. You may find one for a different vehicle that may work.
But they are not cheap.

Ground plane becomes an issue on smaller cars and compromise mounts. Something like a mag mount or bracket mount with a Larsen NMO-27 would be a tolerable option.

 

[mmckenna]

Here ya go:

VINTAGE CB-AM/FM COUPLER ANTENNA SPECIALISTS (AS) ASCR133 NEW OLD STOCK | eBay

Find many great new & used options and get the best deals for VINTAGE CB-AM/FM COUPLER ANTENNA SPECIALISTS (AS) ASCR133 NEW OLD STOCK at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[jassing]

Those couplers allow the radio to use your cb antenna...it doesn't sound like the OP wants to use an am/fm -- just have a cb antenna mounted where his radio antenna currently is.

I did this in an old fiat, but used a right-angle mount and sort of mounted the antenna to the body under the quarter panel so the antenna stuck out thru the hole, but wasn't actually mounted to the hole. (if that makes sense, basically it was mounted out of sight and the antenna stuck up thru the stock radio antenna hole.) It was not ideal, and I had a hard time tuning the antenna, but it did work. Mounting was a whip antenna that took a lot of work to get it so it wouldn't touch the actual body; eventually, I had to put a rubber grommet around the hole so the whip wouldn't make contact with the car body at speed or sudden stops.

Don't try using your am/fm antenna as a cb antenna - that never is tunable...

 

[signal500]

Group President Electronics USA

president-electronics.us

I use this antenna with good results. Mag mount and looks like a standard AM/FM antenna.

 

[FiveFilter]

I believe I would put a lid mount adjacent to the hood. It would avoid problems with the trunk and its rack. One with a four foot stinger would yield relatively good results and should look pretty good while doing it.

Or, if a CB antenna mount could be found to fit the am/fm hole, that would probably be the best solution. Rereading the original post, I believe that was the poster's desire anyway since he has a luggage rack on the trunk.

 

[Token]

I have a Triumph spitfire convertible that I plan on taking on a road trip/rally & I want to take a cb as that is what's being pushed as a "standard".

Trunk would be ideal, but impractical (can't open trunk, plus there is a luggage rack in the way.

I am hopeful to find a nice whip I can mount in lieu of the am/FM antenna.

Otherwise, I'll end up with a trunk lip mount and use a quick disconnect (which I hate) so I can open the trunk with the top up.

Any suggestions?

Out of curiosity, what year Spitfire?

In regards to your question, are you going to use the luggage rack to carry anything? If not you can use it to mount an antenna on. A bottom (like a Tram NH-4HC) / low loaded (like a K40 TR-40BK) or continuously loaded (like a Firestick) mirror mount antenna on the rack near the middle / rear will probably clear the roof when it is up. The trunk does not go up to vertical when open, it stops short at about a 75'ish degree angle. The coax can run forward to the front edge of the trunk, fold under, and go between the trunk and the trunk lip seal. This pinching will eventually cause coax failure, but it may take years before that shows up as an issue. I ran a mag mount antenna on a 1973 Spitfire (no luggage rack) for a number of years with the coax routed this way, and never had a coax failure.

T!

 

[jassing]

I believe I would put a lid mount adjacent to the hood.

As a former spitfire owner, there is no way a lid mount will work with the hood. the bonnet/hood encompasses basically the entire front end (fenders, etc) so there is no lip to mount, except right against the windscreen.

 

[Token]

As a former spitfire owner, there is no way a lid mount will work with the hood. the bonnet/hood encompasses basically the entire front end (fenders, etc) so there is no lip to mount, except right against the windscreen.

There is about a 3 inch panel where the wipers mount between the bottom of the windscreen and the back of the hood. And of course some lip mounts put the antenna over the trunk / hood, so that even if there was no room between the rear of the hood and the windscreen that would be no problem.

However, a lip mount will not work on the hood of a Spitfire for another reason, the lip is the wrong shape. Lip mounts, whether they mount to the moving panel (trunk/hatch/hood) or the fixed part (body under the lip) are generally made with a flat rolled lip in mind. The trunk lid of a Spitfire is not a flat rolled edge, rather it has a 90 degree bend and flat metal (L shaped edge) extending down from the surface for about 3/8 inch. I don't think I have seen a lip mount that will work with that.

T!

 

[mikewazowski]

I’d go with something on the luggage rack myself or even a mag mount on the boot.

 

[K6EEN]

The trunk lid of a Spitfire is not a flat rolled edge, rather it has a 90 degree bend and flat metal (L shaped edge) extending down from the surface for about 3/8 inch. I don't think I have seen a lip mount that will work with that.

Ah, if there's 3/8 inch of L-shaped bent metal all the way around the trunk lid on 4 sides, then a traditional trunk lip mount or one of the newer Japanese multi-axis articulated designs isn't going to work.

The small "New York" mag mount from President Electronics, a small mag mount from Hustler or Road Pro, or a trucker-style 3/8x24 "mirror mount" bolted to the luggage rack may be the way to go.

 

[Token]

Ah, if there's 3/8 inch of L-shaped bent metal all the way around the trunk lid on 4 sides, then a traditional trunk lip mount or one of the newer Japanese multi-axis articulated designs isn't going to work.

My bad, I meant and was talking about the back edge of the hood, not the trunk lid edges.

However the same issue applies to the trunk on the sides. I just went out and checked a few of my Spitfires, I checked a Spitfire 4 (1962), Mk II (1966), Mk III (1967), Mk IV (1973), and a 1500 (1976). And although the lid shaped changed from Mark to Mark, the lips remain the same style across the years. The front edge of the trunk is a typical rolled edge, and a lip mount might work on those. However, you would not be able to open the trunk with the roof up. The side edge of all of them are the same as the back edge of the hood, it is an L shaped lip and a typical lip mount would not fit. The rear edge varies, but none of them appeared suitable for a lip mount.

T!

 

[K6EEN]

The front edge of the trunk is a typical rolled edge, and a lip mount might work on those. However, you would not be able to open the trunk with the roof up.

So the "front" of the trunk is the edge closest to the rear window or passenger seats.

The side edge of all of them are the same as the back edge of the hood, it is an L shaped lip and a typical lip mount would not fit. The rear edge varies, but none of them appeared suitable for a lip mount.

Ok, the other three sides of the trunk are out no matter what the model year of the Spitfire, but the "front" edge closest to the passenger compartment is still in play.

Many of the "base loaded" styles of CB antennas have a ferrule that unscrews from the top of the coil, so you can remove the whip while leaving the base and coil in place. In this way, with a quick few twists, the whip is off, and you can open the trunk and there is usually enough clearance for 4 inches of the base-loaded coil to be left on the mount. The whips are 3 or 4 ft in length, so you can stow the whip in the trunk for driving into a garage or low overhang parking area, or just keeping it out of the way when the CB is not in use. I use this sort of set-up on the trunk lip closest to the passenger seats.

Some antennas like the K40 twist off both the coil and whip, leaving just the mount in place.

 

[west-pac]

I think all of you have forgotten the title of this thread is "Stealth Antenna".

 

[mmckenna]

I think all of you have forgotten the title of this thread is "Stealth Antenna".

And the last time the OP was here was Nov. 16th.

 

[DaveJacobsen]

I thank you for all the advice. I was really hoping to get an antenna in the stock am/fm antenna mount, but it sounds like bolting it to the luggage rack will be my best bet. I don't like magnetic mounts, as they always seem to dull up the paint.

The luggage rack is insulated (somewhat) from the trunk lid, in that the metal makes no direct contact with the lid, there's some rubber underneath at the feet. But the feet are bolted thru the lid, so it does make some contact. Should I put a grounding strap from one of the screws to some unpainted metal of either the trunk lid or body?

I don't get online often, sorry for appear to have abandoned it; I have not!

 

[mmckenna]

I was really hoping to get an antenna in the stock am/fm antenna mount

That's what this does: VINTAGE CB-AM/FM COUPLER ANTENNA SPECIALISTS (AS) ASCR133 NEW OLD STOCK | eBay

You connect it to the existing AM/FM antenna that your car already has.

One side connects to the AM/FM radio and allows you to still use it.
The other side connects to your CB radio and allows you to use that. It's not as efficient as a dedicated CB antenna, but it's better than a lot of the junk antennas that exist.

 

[K6EEN]

Those couplers allow the radio to use your cb antenna...

Not in this case. The ASCR133 was a weird product. It is actually a diplexer to split off the CB frequencies from the FM broadcast, combined with an "antenna tuner" or "antenna coupler" which attempted to match the existing car antenna to the CB 27 MHz frequency.

That's what this does: VINTAGE CB-AM/FM COUPLER ANTENNA SPECIALISTS (AS) ASCR133 NEW OLD STOCK | eBay
You connect it to the existing AM/FM antenna that your car already has.

Yep. The existing 100 MHz FM broadcast band antenna on your car obviously doesn't resonate on 27 MHz, so the "antenna coupler" or "antenna tuner" part was a bit of a trick. Never worked very well, and the product was discontinued. However, if all the OP needs to do is talk to the cars a few hundred yards ahead/behind on the road part of the rally, it may be enough.

 

[DaveJacobsen]

Interesting. I originally wanted to mount a cb antenna where the am/fm antenna is mounted (no new holes, clamps, or magnets); plus I figured I could get a 1/2 or 1/4 whip that would look like an FM antenna.
I'd like to be able to get more than a couple hundred yards, so I think I'll clamp something to the luggage rack.
I gave brief consideration to something like [this] or [this] but I think the body would need to be drilled out, and then I'd need some sort of wedge-shaped spacer to get the angle right to get the antenna vertical.

Thanks!