HT1000 UHF Antenna Lengths

[Stage 2]

Hi all,
I have 2 HT1000's which essentially work wonderfully in every aspect except for one slight problem which I think is an easy fix. When compared to MT1000's I also have, it seems that the HT1000's come up a bit short on the receiving range. I feel that this is due to the MT1000's having a 6" UHF antenna versus the 5 1/4" UHF's on the HT1000's. Both HT1000's have these shorter antennas which have the factory "Motorola UHF" signage on them indicating their authenticity. I have noticed that there are 6" antennas on Ebay for these radios with a range of 435 to 470Mhz which would be just fine for the UHF Ham and GMRS freq's I have in them. Here's what I don't understand. When I went to see if Motorola offered anything similar, in the virtual online catalog for the HT1000, there is what is described as a 6" UHF antenna with a 403 to 520Mhz range listed. The part number is 85052U05. AT the same time, there is no mention of the 5 1/4" factory models that both of my radio's have. Was there a specification change made during production, or, is the 6" antenna in the catalog at the afore mentioned number really the same 5 1/4" one I have already?


If the above is the same antenna, has anyone tried one of the 6" models that are listed on Ebay and, other places? I'm sure my HT1000's would match up to the MT's if they had the same amount of whip. Thanks in advance.

[HLA]

you can't go by the length of the antennae from just what you see. if you were to strip off the plastic you would find that the antennae is 3 or 4 times as long if you stretched it out so it just depends on how tightly the coil is packed and the guage of the wire. and the ht1000 and mt1000 use different types of antennaes, if you look in the center of the ht1000 you will see a pin that is the actual antennae lead and the threaded part is the shielding to where the mt1000 just uses a single conductor threaded connector. so you can't go by just what you see on the outside, different antennaes are made to do specific ranges or sometimes the same rang but with more or less sensitivity. like the standard vhf vs. the stubby vhf, if you took off the plastic and stretched it out they would be the same length, the shorter one is just going to take away from your sensitivity on recieve and less distance on transmit. i'd stay away from the antennaes you seelisted on ebay, they are probablly not oem even if they say they are, there are aftermarket companies putting their own M on it to make it look real but you are going to end up burning up your radio.

[Tom in D.C.]

All well and good about antenna differences, but don't
overlook the fact that the sensitivity of the various radios
might very well be different, and THAT could account for
better sensitivity of one radio versus the other.

Also, on UHF the rubber antennas are usually just a length
of wire, often not even coiled, because the quarter wave
is very roughly six inches. A quarter wave at 450 mHz is
about 6.25 inches, longer for lower and shorter for higher
frequencies. We used to make them up from speedometer
cables before factory made units were widely available.

[ve3nsv]

I would start by unscrewing the antenna and see what colour is at the bottom of it. It maybe be possible that the antenna is for the wrong band split all together.

It wouldn't be the first time I saw a VHF portable come in with a UHF stubby and vise versa.

Red: VHF Wide Band (136-174)
Yellow: VHF Helical (136-151)
Black: VHF Helical (151-162)
Blue: VHF Helical (162-174)
Red: UHF Helical (403-435)
Green: UHF Helical (435-470)
Black: UHF Helical (470=512)
Grey: UHF Wide Band (403-512)
White: 800 Stubby (860-941)
Red: 800 Dipole (looks like elevated feed) (806-870)
Blue: 900 Dipole (896-941)
Red: 800 Whip (looks like UHF but 1-3/4 longer) (806-870)

[Rayjk110]

Heh...yeah. Gotta love those eBay auctions with VHF XTS's with UHF or 800 antennas. I bet that PA had fun.

[Stage 2]

Thank you to all who responded. I understand how antennas work and, what they would look like if the plastic was taken off etc. I also know, like most folks, that even though they may have the same amount of material internally so impedence isn't affected, stubby antennas don't receive as well as their longer counterparts as one responder noted. Stubbys are for more comfort when the radio is worn on a belt. The comfort comes at a price which is poorer performance due to the stubby's shorter height. Can anyone answer my question pertaining to the Motorola part number which I will post again. Is the " 6 inch " antenna now listed in the Motorola catalog for this radio with a band spread of 403 to 520 Mhz part number 8505241U05 actually the same 5 1/4" UHF antenna I now have on both radios which came from 2 different sources? My radios do work well and, I'm confident that the "Motorola UHF" antennas I now have, are the correct units , or, at least were at the time these radios were made. I was just wondering if there was an antenna design change referring to greater length further along in production. It would not be the first time Motorola did this.