very OT,question about an antenna

[Daveroo]

i listen to my police/fire scanner constantly,mostly to aircraft channels,ATC,local airports unicom channels,122.750 which seems to be an air to air,general chat channel,well a few months ago the scanner began to go squelch crazy on every channel,at first i thought it was a stuck mic,so id just lock that channel out,turn it on later,then it began to happen more often,so i got some people and pulled my antenna down,cleaned all the connections and the pipe ect,even cleaned the ground connections,it was better for a day or two,well the last week,id turn the scanner on and EVERY channel was just full squelch.so we pulled the pole down again today and cleaned it all again,and its working for now,but when i try to manually adjust the squelch on the scanner with the knob,it does nothing,,,,seems its gone bad...so i think its my scanner itself,but why would cleaning the connections make it work better for a while?
the setup is a radio shack outdoor discone antenna mounted on a 35 foot 1 1/4" iron pipe,bolted to my shed ,its conneted to my RV with a 50ft RG-58 Coax cable,into a rg-58 connector mounted on the rv and then run into the unit and then to my scanner on my desk.
the cable tested fine when tested by a hammie nieghbor,but what i asked him,and pose to you guys is,,will and antenna go bad?.....its been out in the weather for 12 years now,a bird "crash" knocked one of the rods off some time ago,but didnt seem to make a differance..what do you all say?

[johnh_049]

check all the antenna connection, to the scanner and the antenna.
could be corrosion built up on the connectors.

[Ickie]

moisture ... corrosion , That design is a starduster and i'll bet a new one is on your horizon.

heck just make your own receive anntenna, I believe if you divide 456 by the freq or middle band where you listen, will give you the length in meters it needs to be and hang it from your pole or nearby tree.

[robert41]

I had a similar antenna outside for about 3 or 4 years. After getting out of the radio hobby, I took it apart, for storage, and found much corrosion even though it is stainless. Could be your problem as well.

[TeaSea]

No, an antenna will not go "bad". However, as indicated cable connections are subject to corrosion, as well as the "Elements" that make up the antenna.

This is a standard 1/4 wave VHF Omni-Direction Receive antenna, with a ground plane or counterpoise. As Ickie indicated some manufacturers refer to it as a "Starduster". It's just about ideal for VHF Aviation bands in a fixed location, which is the frequency range you described.

I think you've taken the right steps initially. Take the antenna apart, clean all the elements where they interconnect. CAUTION!! Some elements have a light coating of copper which will look like bad tarnish, but is really healthy conductor. DO NOT clean the copper off by mistake (you would not believe how much damage a PFC with a green pad can do). Check the coax, then check the connectors.

For years in the Army I used OE-254 and RC-292 antenna's, which are very similar to what you have up now. Our SOP was that the antenna would be lowered at least once every two days if we were in a static position, and the elements removed and cleaned with a soft rag, then coated with conductive silicon. You would not believe how much this little bit of effort improved ground mobile comms for us.

I notice you mention GROUND, and I'm assuming this is in reference to a lightning ground....this antenna does not need a ground for send/receive (the lower elements are the ground plane or counterpoise on this configuration). Your transceiver may be able to use a ground for optimum use, something you might want to consider.

Also, height is generally a consideration for antenna efficiency. I do not think in this case since as you indicated it had been working well.

This leaves your transceiver, which based on what you've written is likely where I think your problem lies (DO NOT run out and buy a new transceiver on my say so though!!). Squelch is nothing more than the imposition of an electronic filter. It can be over ridden by bad stuff coming down the antenna, or another local transmitter, or by the filter burning out. HOWEVER, old Army commo guy rule....try the easiest and cheapest solution first. That's the antenna at this point. Next thing though, is to isolate the transceiver....take it to someone else who can test it on their system, or bring theirs to your antenna. I would certainly do that before investing in new kit.

Finally, Ickie's right, you can build your own Antenna if need be, and it's not as hard a you might think. I've built HF, VHF, and UHF Field expedients many times and they generally work very well.

[Daveroo]

thanks to everyone for your input,i have a handheld scanner im going to try to see if its the scanner itself,and we cleaned all the wire(cable) connections today,as far as bringing the antenna down again,well i need other peoples help with that,so i may be awhile,,lol,,but i may try making my own,i did make an antenna back when my uncle wanted me to get into ham radi out of copper pipe,a tee ,an elbow and two caps,looked like and elongated Y,or upside down h,i failed the ham test though,,,,no code plus,,,i kept failing on the atmospheare part,,,the layers,and after my third try,the sheriffs office notified me that due to my spinal injury,they would not accept me into the SAR radio unit because of liability,that upset me and i never tried again.

[TeaSea]

You mentioned you had assistance from a "Hammie". If you decide to re-construct the antenna, he or she should be able to help. Most Ham operators I know yearn for projects just like this. You should be able to rebuild your antenna using mostly the parts it has.

[Motormouse]

As well as cleaning the connectors you may want to treat them with a contact enhancer and corrosion protective,
we use Lektro-Tech Super Corr-A , and ACF-50 to good effect at work

ttfn

Pete