Thoughts on the RS 20-006 telescopic whip antenna

[giallocali]

I believe this is/was the ultimate antenna for a handheld scanner if you could only have one.
I like to monitor everything from CB to Ham to 800MHz Digital.

My only issue with the RS 20-006 is in quality. I still have one that I purchased back in 2003 which is very good at pulling in all the above mentioned frequencies. It trumps the stock duck almost everywhere. However, I purchased a second 20-006 a few years ago and notice it doesn't seem to be made of the same material my older one is made of. Also, it doesn't perform nearly as well as my older one. The stock duck gives it a run for the money on almost every frequency. I read similar comments from a reviewer of that antenna recently who also felt the quality has diminished.

Did I just happen to purchase a dud? Does anyone else concur that the quality of the RS 20-006 has degenerated over the years?

Also, can anyone think of a better all-around, multi-purpose, all band antenna for a handheld scanner?

 

[oschellin]

I have generally found this to be a very good antenna, but have found an interesting quirk on more than one unit. Using a spectrum analyzer I have found that many of those antennas actually perform better when the first element above the coil is actually collapsed. I have found that this can make the difference of several db of signal strength.

 

[n4yek]

I have generally found this to be a very good antenna.

I second that!!!
Mine has been an excellent antenna.

 

[itchy104]

I have the same issue as giallocali. Mine is also recently purchased. The original rubber duckie out performs the 20-006. I listen to State Police, Local and County police, EMS, Amature Radio, and air traffic controllers in the Philly/Delco Pa. area. The rubber duckie works better no matter what I do with the telescoping antenna. I was going to return it end exchange it for a new one, but how to prove that the antenna is not working properly? I don't have any test equipment to speak of. The best I can come up with is a multimeter.

 

[Mike_G_D]

This antenna is an excellent performer when adjusted for the band of interest. Fully extended, it is probably the best portable low band VHF antenna (if it is functioning correctly). It is, however, not intended to work effectively on all bands equally well at one configuration. Use the chart on the back of the package to give you a general idea of what to adjust it for for your particular band of interest (assuming they still have a chart on the back of the package - they used to provide one).

I have two of these and the oldest one has a center pin of the BNC connector which is too long causing it to not be usable on some female BNC connectors. The newer one does not have this problem. However, both are quite old - I can't remember when I bought them.

The loading coil is "shortable"; that is, collapsing the segment just above the loading coil into the coil segment will effectively short out the loading coil so that the antenna then becomes a standard telescoping whip with no center loading. As I said, fully extended, the antenna works well as a portable low band antenna. Shorting out the coil as I mentioned above and then collapsing the lower segments all the way makes the antenna most effective on high band VHF. When the loading coil is shorted (and ONLY when the loading coil is shorted!) just use the formula of 246 divided by the desired frequency in MHz to get the measurement in feet and convert to inches; this will get you pretty close. In this configuration it is also effective for transmitting.

If you are noticing that the antenna is performing poorly on low band when fully extended then it may have a bad loading coil or one wherein the series connection is flaky. If all you have is a multimeter then try checking for continuity between the bottom most segment and the top most when fully extended. If you don't get continuity then try collapsing the loading coil shorting segment (as mentioned above that is the segment just above the loading coil) and seeing if continuity now is good. If so, then it may be a bad loading coil. Try spinning the coil segment around and repeatedly collapsing and pulling out the shorting segment also - the connections are likely prone to getting dirty and/or worn.

To summarize, if you are mostly interested in low band then fully extend the antenna with the loading coil engaged; if you are mostly interested in high band then short the coil by collapsing the segment above the coil inward (downward) and then collapsing the lower segments fully; everything collapsed but the last three segments should be about right for UHF and collapsing everything all the way should be best for 800MHz. Use the formula above to better zero in on the desired band/frequency.

-Mike

 

[Josh]

I can't speak for the newer antennas as I haven't needed one in a while, the price on them has gone up and up- the last one I bought was retail priced at $9.99

Back when I was using my handheld scanner for everything because it was the only thing I had, I don't know how I went without this antenna. I primarily listen to VHF, so using just the top few segments with the one above the coil collapsed, per the instructions, is how it worked best for me. I collapsed sections sooooooooooooo many times though that the antenna eventually quit staying up, segments would collapse due to the weight of the rest of the antenna after a while, so another had to be purchased.

I probably had about 4 of these over all, and still have the last one and it's still holding up. On a couple of them, I've even shorted out that coil by unwinding it and soldering a short straight line to the opposite connection, cured the "pulling the antenna all the way out" signal reduction problem.

I highly recommend them still even if they are, what, $20 now!?

 

[giallocali]

................If you are noticing that the antenna is performing poorly on low band when fully extended then it may have a bad loading coil or one wherein the series connection is flaky. If all you have is a multimeter then try checking for continuity between the bottom most segment and the top most when fully extended. If you don't get continuity then try collapsing the loading coil shorting segment (as mentioned above that is the segment just above the loading coil) and seeing if continuity now is good. If so, then it may be a bad loading coil. Try spinning the coil segment around and repeatedly collapsing and pulling out the shorting segment also - the connections are likely prone to getting dirty and/or worn.....................

-Mike

Great post, thank you Mike.
As the original poster of this thread, I've always known about the various lengths for various frequencies with this antenna. In fact, when I first got one, I photocopied the frequency info from the manual and shrunk it enough to tape on the inside of the battery cover for reference.

The newer one I have is just plain terrible no matter what I do with the length. I'm hoping that I just have a bad coil and that a good 20-006 antenna can still be purchased.

Thanks again for the thorough explanation!

 

[itchy104]

Thank you for the information Mike. I was a little suprised when I had trouble with the antenna. The research I had done before buying it listed it as a good performer. I'll try your suggestions tonight.

 

[MarMatthias]

Hi,

I have this antenna and it has made a huge impact on my 396XT reception. With the antenna that came with the unit, I had very poor reception, even for very close frequencies, and I could not receive anything over 10 miles. Its a purchase I'll easily recommend.