Nagoya NA-771 antenna for Baofeng HT

Started by raybiker73, November 11, 2012, 03:18:13 AM

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White Tiger

Quote from: cockpitbob on November 26, 2012, 03:52:53 PM
Good idea about the rat tail.  I'll give that a try and report back.

Have you tried the rat tail yet? My NA-771 is due in next week, wondering if you've seen some improvement?
If you're looking for me, you're probably looking in the wrong place.

cockpitbob

#16
I'll give it a try tonight while some local nets are happening.

The Nagoya may be worth it for Baofeng owners. There's a good chance that it's better than the Baofeng antenna, and that Yaesu just makes an excellent 7" duck.

cockpitbob

#17
I repeated my antenna tests. this time with a rat tail, and I'm impressed with rat tails!!!  For a rat tail I cut a piece of 22AWG stranded, insulated wire to 19.5" and stripped 1".  I wrapped the 1" of bare wire around the SMA connector before screwing the antenna on.  In use I made sure it hung down. 

I compared the stock 7" Yaesu duck, the Nagoya and the shirt-pocket roll-up J-pole.  Naturally I didn't use the rat tail with the J-pole.  Here's the S-meter results from a somewhat distant 2M repeater:

ANTENNA     NO RAT     WITH RAT
Yaesu             S5            S8 to S9+20
Nagoya           S5            S8 to S9+20
J-pole             S8       

With the rat there was a bit more sensitivity to where outside I was standing(S-meter moving up and down as I walked around), but wholy-cow, what a difference.  All I can say is that I'm a rat tail convert.  That magic little piece of wire is now in my HT travel bag.

White Tiger

Quote from: cockpitbob on December 02, 2012, 10:04:11 PM
I repeated my antenna tests. this time with a rat tail, and I'm impressed with rat tails!!!  For a rat tail I cut a piece of 22AWG stranded, insulated wire to 19.5" and stripped 1".  I wrapped the 1" of bare wire and around the SMA connector before screwing the antenna on.  In use I made sure it hung down. 

I compared the stock 7" Yaesu duck, the Nagoya and the shirt-pocket roll-up J-pole.  Naturally I didn't use the rat tail with the J-pole.  Here's the S-meter results from a somewhat distant 2M repeater:

ANTENNA     NO RAT     WITH RAT
Yaesu             S5            S8 to S9+20
Nagoya           S5            S8 to S9+20
J-pole             S8       

With the rat there was a bit more sensitivity to where outside I was standing(S-meter moving up and down as I walked around), but wholy-cow, what a difference.  All I can say is that I'm a rat tail convert.  That magic little piece of wire is now in my HT travel bag.
excellent news - thanks for the follow up! Sounds like I'll be a covert too!
If you're looking for me, you're probably looking in the wrong place.

Geek

Sorry to reopen an old thread, but it seemed more appropriate than starting a new one.  I just received one of the Nagoya 771 antennas and put it on my Yaesu HT and thought others might be interested.  The antenna is about twice as long as the standard rubber duck and much thinner and more flexible.  To my ear, with no test instruments, it seems to be an improvement, giving clear signals where I might have gotten static with the stock antenna.  I like it as a cheap upgrade to my HT.

Be careful to get the right one for your radio so you don't wind up looking at the wrong connection.

cockpitbob

Hi Geek,
Now just add a rat tail and you'll really be able to hit the repeaters.

Also, I think not starting a new thread is the right thing to do.

--Bob

Geek

I have some wire and some terminals, but the wire seems very thin and the terminals are the crush type.  I am wondering if I really need to solder the connection or should just give it a shot with a pair of pliers.

cockpitbob

Go for it.  The worst that could happen is the wire will pull out.  I used a small crush terminal and put it under one of the belt clip screws.  I think I used 24AWG wire, which is pretty skinny. 

Geek

I couldn't get the terminal to fit under the belt clip screw, so I tried just wrapping the bare end of the wire around the screw and tightened the screw.  Again with no instruments other than my imagination and my ears I tried out the radio.  It seemed louder, as though I had turned the volume up a notch or two.  I let the scanner rotate through the 2m band and picked up Oswego, NY.  That's a bit further than I have previously picked up and is about 250 miles as the crow flies.  I would have expected at least one hill in the way as well.

I confess I don't understand why this works, but I am sold on the fact it does.

Quietguy

Quote from: Geek on April 20, 2013, 09:27:35 PMI confess I don't understand why this works, but I am sold on the fact it does.

Geek, the reason it works is actually pretty simple - the ducky is only half an antenna.  Handhelds rely on capacitive coupling from the radio's body to your hand to provide the "counterpoise", or missing antenna ground, which only sorta works.  Adding a rat tail forms a dipole antenna between the rat tail and the ducky, which greatly improves performance.  It is the same principle as using an HF vertical with and without ground radials.

Wally

Geek

Should the length of wire be related to the length of the antenna?  For instance, if I switch from the rubber duck to the Nagoya, which is longer, do I need a longer rat tail?

cockpitbob

Quote from: Geek on April 21, 2013, 08:03:39 AM
Should the length of wire be related to the length of the antenna?  For instance, if I switch from the rubber duck to the Nagoya, which is longer, do I need a longer rat tail?
The tail should be 1/4 wavelength at the operating frequency, regardless of which antenna.

With the rat tail you basically have a resonant dipole with the duck being one end and the rat tail being the other.  Internally the duck is loaded (coiled) so it is physically shorter than 1/4wave but electrically it is the right length to resonate at 2M frequencies.  I put a piece of wire on my antenna analyzer and trimmed it for resonance at 146MHz and it was 18.5" long, so that's how long my tails are.  Theory says it should be 19.2" but the insulation on the wire slows things down a tiny bit.

Geek

So on the 2m band my 19" rat tail is fine.  Cool.  If I go to another band I need to worry about it.

Paladin

Good thread! I ordered one of the NA-771's for my FT60 last week. I figure for the $9 I paid for it, even if it's junk I'm not out too much. Hopefully it improves my ability to hit some of the more distant repeaters around here. I'm in a tough location for hitting repeaters with an HT. Mobile or base is no problem, but with an HT I can BARELY hit the machines. Signal reports aren't great and I have a tough time holding the machines.

PS: Ed Fong is a good guy! I have one of his PVC J-poles for my base 2m. He's very helpful, and his simple little J-pole works great.

s2man

Quote from: Quietguy on April 21, 2013, 12:12:22 AMHandhelds rely on capacitive coupling from the radio's body to your hand to provide the "counterpoise", or missing antenna ground, which only sorta works.  Adding a rat tail forms a dipole antenna between the rat tail and the ducky, which greatly improves performance.

Wally, Does this mean performance would be even poorer if the HT were used with an external mike/speaker, with no body contact to the HT?  If so, that would be an even greater reason to use a rat tail...