Batboard

I've searched the board, and can't seem to find anywhere that this subject has been covered yet.

I currently have a Larsen NMO dual-band 3db gain antenna permanantly mounted on the roof of my truck, and am getting ready to do an L-bracket (I know, I know...) NMO 1/4 wave VHF antenna at the hood. I'd like to paint these black, but was wondering if this would cause any performance issues? If not, any suggestions - just regular black spray paint?

Thanks, always enjoy the wealth of knowledge on here!

I've done it before without any ill effects. The main problem with using paint though is its not as flexible as the metal whip, and eventually starts to crack. I'm not sure what most companies use as a coating on their antennas, but i would guess its probably more of a dying process, like bluing a rifle barrel since it doesn't build up on the surface like paint does.

If you want to paint them, just make sure you use a paint that doesn't have any metallic particles in it, like a metal flake paint or something fancy of that nature. They could possibly affect the antenna, although perhaps not to a noticeable extent.

I know that on eHam about 4-5 months ago a guy was talking about dipping some antenna whips into bluing solution, he got them fairly dark by leaving them in for a while.

Why paint them when you can buy them black already?

For your dual-band, I'd recommend a Radiall/Larsen 2/70 in black. For the 1/4 wave, look at a Maxrad BMFT120. Maxrad also sells black L-brackets. The quality of the finish is much, much better (for instance, the Larsen antenna is black chrome - unless you erode the metal, it stays black), and it's less hassle. You're probably looking at $50 for all of the above.

You are better off buying black. I painted a few different whips for a "stealth" look. Full prep w sanding etc, but no matter what it wears off and starts to look crapy.
Mike

Yep, it just doesn't hold up.

tvsjr wrote:Why paint them when you can buy them black already?

Well, I was just being cheap. The dual-bander is well over 10 years old, so a new black one might have to be a Christmas present to myself!

Thanks for the suggestions, I'll go shopping this weekend...

mikerabbit wrote:You are better off buying black. I painted a few different whips for a "stealth" look. Full prep w sanding etc, but no matter what it wears off and starts to look crapy.
Mike

The problem with sanding and such is skin effect. The higher the frequency of the RF, the more the RF travels only on the surface of the conductor. And in this case, you're messing up the surface the RF is going to try to flow over.

This is the one bad side the the Larsen "kulrod" stuff. It pits and there is a measureable loss of performance. Probably not enough to notice in a "controlled" environment (like a PS system designed for a certain area) but hams might notice a loss of performance.

Just something to consider.

I experienced the same problem with painting. It looks OK for a few weeks, then starts to look bad, then worse.

I finally got some small diameter heat shrink tubing and used that. May not be perfect, but was cheaper than ordering another antenna.
Yes, I did use black, but I guess there are other colors out there if you really wanted to "stand out".

I bought mine black and even this color on them will wear off. I wonder if power coating them would be any better?

Darrin

I keep a black Sharpie in my truck. Once it starts turning silver again, I take about 1 minute to recolor it!

I'm wondering about moisture buildup/corrosion after awhile. If it is true that the RF travels more to the outside, this could be a problem. Plus, u've got added width/wind resistance that will make it dance at speed.
BTW, does the black 'blend' beter with the environment or something (dark truck??) I just don't see the problem with a whip color.

tiredfireman wrote:I'm wondering about moisture buildup/corrosion after awhile. If it is true that the RF travels more to the outside, this could be a problem. Plus, u've got added width/wind resistance that will make it dance at speed.
BTW, does the black 'blend' beter with the environment or something (dark truck??) I just don't see the problem with a whip color.

Mine work fine after a year or two. They get replaced every now and then (folded, spindled, and mutilated by a low-hanging tree branch, usually... and I think the aircraft AM antenna has been replaced more than any of them). A few have high-power Spectras tied to them, absolutely no issues. They don't dance/sing at speed (well, up to the speed limiter at 106.3MPH).

Yes, they *absolutely* blend in better. I've got 15 NMO mounts on the roof... 13 using Maxrad .062"-diameter black antennas (other two are a gain antenna on 2.4GHz and a RadiallLarsen GPS puck.) This is on a black Expedition. Unless you know what you're looking for, and the background is right, they're just about invisible. Put some trees behind the vehicle, and you can't even tell they're there.

Plus chrome whips on a black truck simply look bad. You wouldn't put a chrome grill guard or spotlight on a black truck, would you?

my truck is all maxrad black whips and can antennas and just like tvsjr'
s rig you can't see then unless you know what to look for or just happen to have the right lighting.

13 antennas? I thought I had a lot with 7!

Ok, weird thought, but what about the ruber-izer stuff that people like to dip gloves in? you can get it in pretty close to most vehicle colors, and it's non metallic, seems like it might be perfect for an antenna dip. Has anyone ever tried it?

[quote="tiredfireman"]... Plus, u've got added width/wind resistance that will make it dance at speed.
quote]

It's a UHF 1/4 wave, so, no, no problems with wind resistance or dancing.

And, as was stated, on a dark truck, it does blend in better.

I have had this set up for several years, and no problems. I did leave a small gap at the bottom, so there is a bit of a drain path. The heat shrink is on there pretty tight, I doubt that much moisture, if any could get underneath.

I agree though, I probably wouldn't try this on a VHF 5/8's

apco25 wrote:my truck is all maxrad black whips and can antennas and just like tvsjr'
s rig you can't see then unless you know what to look for or just happen to have the right lighting.

13 antennas? I thought I had a lot with 7!

The grand total is actually 18... if you want to include the dual-band and CB antennas mounted on the front fenders (lip mounts - hamsexy!), the antennas on the roof, and the XM puck (and yes, XM is better than Sirius! *ducks*) There's a lot around my area to interoperate with (VHF, UHF, Motorola and Ericsson 800, analog, IMBE, ad nauseum) so additional radios are required. I could cut the number down if I wanted - don't necessarily need the GPS puck on the roof, nor the 2.4, etc., but hard-mounted antennas simply work better. I've also got a spare mount that I can stick an antenna on and plug into anything temporary (radio, my spectrum analyzer, etc.)

The thin black antennas just make sense. I've got all the antennas, overt red lights to the front, an ArrowStik hanging in the back deck, etc., and 99.9% of the population *still* don't pick me off for being anything other than one more driver. At least until I find the appropriate switches...

pix?

Why not use heat shrink tubing?

M3SGC

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