shorty antenna

[Vol1chuck]

After installing my mp3 luggage rack, I realized that my luggage was too wide because of the antenna. Found this one on ebay. Not a perfect match and the reception does suffer a little, but it's an easy fix for trips.

[junkyarddog]

Did you get yours from Mangowalk.com? I tried several different rubber items to "fill in the gap". A rubber grommet, spark plug boot w/ the small end cut off and part of a rubber from a ball point pen. The pen thing works the best and its basically waterproof. It looks kinda cool w/ a short antenna too.

[srt8-in-largo]

I'd hit it with a shot of matte black paint to blend it in...

[stepbill]

After installing my mp3 luggage rack, I realized that my luggage was too wide because of the antenna. Found this one on ebay. Not a perfect match and the reception does suffer a little, but it's an easy fix for trips.

Do you have a link or the name of the antenna so we can do a search on ebay?

[hiflyer]

Do you have a link or the name of the antenna so we can do a search on ebay?

http://www.mangowalk.com/index.php?sku=30378

[GiddyupF6B]

Did this screw right in or did you need an adapter or another bolt?

[Vol1chuck]

Do you have a link or the name of the antenna so we can do a search on ebay?

The ebay seller is "baostoner". Fast shipper.

[Vol1chuck]

Did this screw right in or did you need an adapter or another bolt?

Actually came with three different adapters and two rubber grommets to fill the gap and make waterproof.

[Vol1chuck]

I'd hit it with a shot of matte black paint to blend it in...

Excellent idea! That would make it look almost stock.

[GiddyupF6B]

Just ordered one...thanks!

[53driver]

I'd hit it with a shot of matte black paint to blend it in...

On military aircraft we never paint antennae for performance reasons....not sure how much that would apply here, being receive only.

[srt8-in-largo]

Great point 53. Antennas are always bidirectional; if you can receive with it, you can transmit with it and vice versa. Anything that affects reception will also affect transmission. If you happen to see a "beam pattern" published for an antenna, this pattern applies to both transmit and receive.

In critical applications (i.e. life and death) I'd never suggest doing anything that compromises communications, but you may be able to get away with it here without too much impact.

Everything electricity related is governed by two forces, electric and magnetic. The electric field has an effect on metals, "metals" being the chemistry definition... a molecular structure that has a "sea" of free electrons. The magnetic field has an effect *only* on ferrous materials; if there's no iron in it, it's essentially invisible to mag fields. I would be as certain as I could that the paint has no metal or iron in it.

An electromagnetic wave propagating through the air is also affected by dielectric properties of materials, permittivity and permeability. This factor is exactly why submarines have trouble communicating using radios. Sea water has different dielectric properties than air, and when subs transmit a signal from deep below, when that signal hits the air-water boundary it's mostly reflected back into the water and can't get up into the air where it can be received. The paint adds a tiny dielectric discontinuity... and will introduce small losses and reflections of the radio signal. I wouldn't expect it to be too bad though.

Reception and performance of shorty antennas are already compromised by it being a "shorty". A perfect antenna to receive (or transmit) should be exactly 1/4 wavelength of the signal. Instead of having a straight wire antenna, shorties typically coil the wire up, so that the length of the wire is as close as possible to 1/4 wavelength, but just curled up. Unfortunately this doesn't work as good as a straight antenna, but sometimes good enough.

[53driver]

...A perfect antenna to receive (or transmit) should be exactly 1/4 wavelength of the signal. Instead of having a straight wire antenna, shorties typically coil the wire up, so that the length of the wire is as close as possible to 1/4 wavelength, but just curled up. Unfortunately this doesn't work as good as a straight antenna, but sometimes good enough.

Oh yes...I was a CB operator for many years. Understand all of that and more.

My point was that the OP (Vol1chuck) mentioned that performance had already suffered.
While none of us are expecting an "acoustically perfect anechoic chamber audiophile solution" on our bikes, Chuck needs to decide if any further degradation in performance is warranted for mere aesthetics.

[Doug44]

Oh yes...I was a CB operator for many years. Understand all of that and more.

My point was that the OP (Vol1chuck) mentioned that performance had already suffered.
While none of us are expecting an "acoustically perfect anechoic chamber audiophile solution" on our bikes, Chuck needs to decide if any further degradation in performance is warranted for mere aesthetics.

Hey I am a Amateur (ham) radio operator I gotta get in on this also

1/4 wave on A.M. Broadcast band is around 150 ft a bit long to drag
1/4 wave on F.M. Band around 2 ft.

Solution------tune off the radio and listen to that sweet six

[srt8-in-largo]

Gotcha 53... sometimes I'm rambler of both the highway AND the keyboard.

What frequency does HAM operate on? I'm told ham signals bounce off the atmosphere, which is how you're able to communicate around the globe.

Antenna design has some other tricks that I'm not familiar with. The antenna I use in my TPMS sensor is less than 1 inch, yet 1/4 wavelength at 325 MHz is 9 inches and somehow they made it to work pretty good. I suppose a signal amplifier can be built in... which now makes me wonder if there's a shorty antenna with something like this that won't see any performance degradation.

[stroguy]

My wifey enjoys the full length of my stock antenna.

No paint but you could dip it in Plasti Dip black.