VHF Portable Antennas Performance (Old vs. New)

[kennethlbryant]

Has anybody studied the difference in performance between the old style helical (uniform thickness) antennas and the new style base loaded (tapered towards the top) antennas which is now the new style by Motorola?

I am interested in a factual comparision based on a technical analysis rather than anecdotal information (individual preference).

[Will]

Our lab tests showed the tapered VHF antennas sucked bad. Motorola replaced them with the good ole GP300/P200 antennas. These have thicker spring wire, wider spaced turns and more lenth which gives wider bandwidth and better TX RX performance..

The tapered antennas are made in China and cost Motorola less that 50 cents.

Get a REAL antenna, get a Centurion. http://www.centurion.com

[kennethlbryant]

When you say the good ol' GP300/P200 antennas?

Did you test the 7.5" NAD6579 tapered high performance antenna?

[wb0qqk]

I'm using the 8505834W01 Helical, 136-151 MHz, 5" high
antenna on my XTS5000. I can receive NWS broadcasts
from a transmitter located 80 miles away and 90% of the
local ham repeaters are full smack TX/RX too.

Is there something better than that out there? Let me know
because I want to buy it !!

[kennethlbryant]

Motorola says the NAD 6579 is best it is rated 148-162. Motorola specifically says it is "Enhanced Performance." They are hard to get, I have them new (got for myself - I need the best performance) but I have not tested them yet.

They are for the MX connector, is that what the XTS has?

[wb0qqk]

They are for the MX connector, is that what the XTS has?

I believe the XTS uses the 'SF' connector. An 'MX' connector
would probably short out the center pin of an XTS, MTS or
HT1000 series radio and damage it.

[RadioSouth]

I'm using the 8505834W01 Helical, 136-151 MHz, 5" high
antenna on my XTS5000. I can receive NWS broadcasts
from a transmitter located 80 miles away and 90% of the
local ham repeaters are full smack TX/RX too.

Is there something better than that out there? Let me know
because I want to buy it !!

Actually there is, sounds like you're getting A-OK performance with the Visar style antenna you're using but you could kick it up a notch with the 85-05644v02 150.8-162 antenna
or the
85-05518v01 136-178 wideband

Both of these give slightly better talkout then what you're using, but they're about 2" longer and thicker (a result most of us males would be delighted with) but seriously either of these will work slightly better but to me the larger profile isn't worth the tradeoff as I'm in a high density area, out in the rural there is a noticeable difference on the system fringes. I did informal testing by going to 10 different location and was switching antenna's back and forth while getting 'S' meter reading from the base station there was up to a 2 'S' unit difference in a few locations. Yeah, I know there are better ways to spend an afternoon and based on only the small difference I was able to get them to trade us to the Visar style antenna's on the MT2000's we were using. A better option as most of the guys were using the radios with the antenna top rubber banded to the base in a 'U' fashion.

[kennethlbryant]

These antennas you mention 85-05644v02 150.8-162 or the
85-05518v01 136-178 wideband, are they the new tapered style or are they helical? Do you have pictures of what they look like?

[RadioSouth]

The one is a helical the wide band they call a dipole. These are the center pin type antenna's. What radio type you using ?

[kennethlbryant]

I am using the Pro Series HT 750/HT 1550.

I just bought the enhanced 7.5" NAD6579 148-162 and was wondering if there was better out there in Motorola land. This antenna is for the Pro HT series. I need pictures because everybody describes antennas differently (misuse of terms). The NAD is the new tapered style.

[RadioSouth]

Can't use the ones I mentioned for the Waris radios. Haven't heard of the hi performance type you mention, sounds like it might be something new. As Will mentioned these cone shaped antenna's that come standard with the VHF radios bite, I'm using the GP300 type on mine. NAD is a prefix used on many antenna's as is the 85 prefix. To further confuse things many identical antenna's carry both prefix part#'s and are used depending on which division sells it.

[kennethlbryant]

Which Division or part number is usually the cheapest?

[Cam]

I just like to use the old 1/4 wave on my vhf portables, it really helps me "get out".

[va3wxm]

What do you use for a counterpoise?

[RRrobby]

The Michigan DNR and the USFS fire setrvice use 1/4 wave antennas for their King radios. They work better than anything else that they have tries, especially in the UP of Michigan. The only disadvantage is that they are 18" long and can sometimes poke out your armpit. As with any other portable antenna, they need no counterpoise. I do have a few of the local FD's use them in areas that have poor coverqage. My personal preference is the Centurian style H (now EXH) base load 1/4 wave. Good trade for me between the performance of the 1/4 wave and the long length. Unfortunately, they only come in stud mount versions (BK, HT750, GP300, etc). They do not make an antenna for the HT1000 or others that use the SMA or other coax type connectors-RRRobby

[Cam]

What do you use for a counterpoise?

The same thing I use when I use a 1/4 wave on my UHF or when someone uses the cute little 800/900mhz 1/4.

[Cowthief]

Hello.

The best antennas are what the application calls for.
A quarter wave "skinny wire" antenna tuned to the frequency of interest will have over 6Db of gain over the helicoil antenna, but will be 18" long at 155 MHz.
The elevated feed skinny wire is twice as long, but gives an extra 2+ Db of gain.
The skinny wire antenna can be rolled up and kept inside a coat pocket.
The standard helicoil antenna is quite broad-banded and very compact.
Some ham antennas are available with a telescoping section and are part helicoil.
There is also the standard telescoping antenna, however the things are easily broken.
So, as you can see, there are options.

[kennethlbryant]

Can anybody address the following PLEASE!!!

Has anybody studied the difference in performance between the old style helical (uniform thickness) antennas and the new style base loaded (tapered towards the top) antennas which is now the new style by Motorola?

I am interested in a factual comparision based on a technical analysis rather than anecdotal information (individual preference).

[Cam]

Can anybody address the following PLEASE!!!

Has anybody studied the difference in performance between the old style helical (uniform thickness) antennas and the new style base loaded (tapered towards the top) antennas which is now the new style by Motorola?

I am interested in a factual comparision based on a technical analysis rather than anecdotal information (individual preference).

Don't cry about it.

The following is based on my own experience and nothing more.

Many of the early HT750/HT1250/HT1550 came with the 8504762J01 "Whip".

Those suck.
So the VHF Whip Antenna, 148-161 MHz (Enhanced Performance, 7.5") NAD6579 does seem to work much better then this.

IMHO I can not tell a difference between the HAD9728 (GP300/P1225) 6" VHF kit 146-174 if it is tuned to the right freq range.

[Hoseman292]

Thanks for the good info CAM. I've always wondered if I ever purchased one of the newer radios would I be forced into using an antenna that resembles a sex toy. I'm glad there are more traditional antenna options.


Tim