Tiger Tails

Started by Mitch, October 25, 2012, 10:34:44 AM

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Mitch

Nope, it's not something you go to the zoo to see!  :D

New technical fact for those who didn't already know:

When you operate a handheld transceiver (HT or "Handy Talkie") the manufacturer of that radio is using the metal case and your body for half of the antenna. This is true for any HT with a short durable rubber ducky type antenna. It's not the optimal setup like having a dipole or a vertical with counterpoise!


My obervations and question:

I like to clip my HT on my daypack (small backpack) when I go hiking; the radio then has a speaker-mike that clips to the front straps for me to actually operate with. The good part of this is that the antenna isn't being held close to my body like it would be on my belt (better/safer antenna operation) this also prevents me from actually holding the unit and providing a good RF ground for the antenna (worse antenna operation). I usually provide a better RF ground to my HT by hanging a tuned wire off the antenna connector negative lead (the metal that the screw in connector is made of) this is affectionately called a "tiger tail".

I haven't had  much issue making and using a tiger tail before, but my new trail radio is a Baofeng UV-5R with something like a reverse SMA connector for the antenna. This doesn't lend itself to easily attaching a thin wire or a flat washer to it for a tiger tail... To make matters worse the Nagoya "rubber ducky" antenna that comes with the unit uses the flat space around the antenna connector as mechanical support by sealing the bottom of the pyramid shaped antenna rubber base against the body of the radio. Because of this feature I'd like to attach my tiger tail to the case under a case screw; however I can't find anywhere if this is acceptable from a technical standpoint. It just doesn't seem to be done like that anywhere I've looked- does anyone here have an opinion on this?


gil

What about using the plug used to charge the battery? Get a similar plug and connect the wire to the negative pin...?

Gil.

Mitch

If I could check a schematic and be assured it is common that would be good as a tiger tail attached to the case, but I wouldn't do that since if the tail catches on the brush it may pull the plug out and/or "stress" the jack. That is a PITA repair usually (on a cellphone especially)...

I'm still not sure a tiger tail attached to the case is as good as placing it at the antenna connection.



Striving for that extra mile on transmit!!!

Mitch

Heh, I just remembered-

It's my ICOM IC-92AD HT that has the battery charging jack not the Baofeng UV-5R!

The UV-5R doesn't even have one, you have to charge the batteries in the desk charger which hasn't been an issue yet. The stock batteries last forever in these units and I just bought a couple spares because they are so cheap. $15 for the Baofeng battery and $115 for the Icom batteries   >:(

Paul

Those 'tiger tails' are also called 'rat tails' and are fairly common, been around for a while.  They do work.  Don't expect miracles from them but they should at least improve whatever your present antenna can do.  If you swap the typical rubberduck that comes with most HTs for a real live 1/4 wave, then that 'rat'/'tiger' tail can certainly make a noticeable difference (still don't expect huge improvements though).
I use a home made one on an HT.  Plain old insulated wire that happened to be handy.  Tried connecting it at the base of the antenna but the case got in the way and it usually didn't stay very long.  So, since the battery snaps on to the back of the HT, and the frame of the HT is metal and exposed under that battery, I coiled up some of the bare wire and put it between battery and metal frame when I replaced the battery.  Genius, huh??  Yeah, right.  Anyway, it works just dandy.  You do want to keep it away from the power contacts (both +/-), that connection really doesn't do anything beneficial.  You also might want to insulate the end of that 'tail', it 'do' get RF 'hot' when you transmit.  How long for that 'tail'?  Probably at least as long as the antenna on the HT, or a 1/4 wave length.  A little too long won't hurt anything.  If you step on it when you walk, it's too long...
- Paul