Broadband HT antenna?
 

Does anyone make a telescoping HT antenna meant to operate (1/4 wave)
over a broad band of frequencies with marking for those frequencies?

Most HT's can be modified to operate outside the amateur bands, like on
GMRS, MURS, FRS, etc. But I don't like doing this without a proper antenna.

It would be simple enough to make a 1/4 wave telescoping antenna with
calibration marks for everything VHF and UHF, just extend it to the
right length. It would have an easy way to set it to the right length.
Does anyone make an antenna like this?

TNX,
Bruce AF8F

Bruce W.1 wrote:
Does anyone make a telescoping HT antenna meant to operate (1/4 wave)
over a broad band of frequencies with marking for those frequencies?

I think I saw one that was advertised as 1/4 wave on 70cm when closed,
1/4 wave on 2m when fully extended. Can't remember the brand, or where
I saw it, though.

-j

In article ,
Bruce W.1 wrote:

Does anyone make a telescoping HT antenna meant to operate (1/4 wave)
over a broad band of frequencies with marking for those frequencies?

I've seen one or two such on a dealer's table at a local hamfest,
although I'm not sure that they come pre-marked - the package gave
instructions for the number of segments to collapse to achieve
resonance on 220 and 440. I think one was made by ADI and/or Premier
but I can't be sure.

Most HT's can be modified to operate outside the amateur bands, like on
GMRS, MURS, FRS, etc. But I don't like doing this without a proper antenna.

You really shouldn't do it (well, at least, not transmit) even _with_
a proper antenna. Very few, if any amateur-radio HTs are certificated
for transmission on those bands, and using an "opened-up" ham HT to
transmit (even if you have a suitable GMRS license) is a rules
violation which could cost you your amateur ticket.

FRS and GMRS have very strict technical rules about the frequency
accuracy of their oscillators due to the tight inter-channel spacings,
and it's likely that at least some ham HTs are too sloppy in design
(or too poorly calibrated) to hit the frequencies accurately.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

On Tue, 05 Apr 2005 10:38:47 -0500, Joe User
wrote:

Bruce W.1 wrote:
Does anyone make a telescoping HT antenna meant to operate (1/4 wave)
over a broad band of frequencies with marking for those frequencies?

I think I saw one that was advertised as 1/4 wave on 70cm when closed,
1/4 wave on 2m when fully extended. Can't remember the brand, or where
I saw it, though.

-j

Radio Shack sells one. I have one, but I wouldn't want to hang it on
an HT connector. Too heavy. I use it on a Bearcat scanner.
http://www.radioshack.com/product.as...ct%5Fid=20-161

Dick - W6CCD

"Dick" LeadWinger wrote in message
...
On Tue, 05 Apr 2005 10:38:47 -0500, Joe User
wrote:

Bruce W.1 wrote:
Does anyone make a telescoping HT antenna meant to operate (1/4 wave)
over a broad band of frequencies with marking for those frequencies?

I think I saw one that was advertised as 1/4 wave on 70cm when closed,
1/4 wave on 2m when fully extended. Can't remember the brand, or where
I saw it, though.

-j

Radio Shack sells one. I have one, but I wouldn't want to hang it on
an HT connector. Too heavy. I use it on a Bearcat scanner.
http://www.radioshack.com/product.as...ct%5Fid=20-161

Dick - W6CCD

I can agree with Dick... I have 2 such Radio Shack antennas. I use one for
my Service Monitor, the other is for any other test purpose I may have, NOT
for replacement for an H.T. A tad too heavy. They were heavy for like the
HTX 202, if you used it on one of the micro radios out now days, the thing
would be top heavy.

cl

I agree. You run into the same problems that Public Safety radios
have to deal with. That is, trying to operate over a wide range
perhaps 150 -174 MHz with a high power radio. Certainly the 1/4 wave
is the best you can do to avoid shutdown of the radio.

For Dual-band 2m/440 operation and in particular when operating MARS,
a 1/4 wave 144 MHz antenna will provide a more satisfactory load at
UHF as well, although with a compromised pattern on those
frequencies.

One of the most frightening tests I performed with 2m/440 ham
antennas was that they were extremely sharp in bandwidth and resulted
in extreme SWR beyond -+ 2-3 MHz on either band.

Public safety personnel often don't understand how hams can have high
performance dual band antennas and they can't. Some suspiciously
consider a conspiracy. The simple answer lies in the frequency
coordination of the repeater frequencies on both bands, and the
narrow but coincidental sliver of frequencies we use for mobile
operation.

If you have a telescopic whip you are blessed. Carry a tape measure
and chart with you.

Of course there are other issues regarding MURS, GMRS and FRS that
are completely awkward and you might as well carry a real FRS radio
along with a Commercial radio with a bank devoted to the ham bands on
your bat-belt.

I contest the mentality that says you should "open up" a ham radio
for "emergency use only" because you compromise the emergency
situation by not using a radio up to the task. You can use a
"church-key" as a can opener, but if you are truly serious you will
pack a can opener.

Jim, ac6tk


"Dave Platt" wrote in message
...
In article ,
Bruce W.1 wrote:

Does anyone make a telescoping HT antenna meant to operate (1/4
wave)
over a broad band of frequencies with marking for those
frequencies?

I've seen one or two such on a dealer's table at a local hamfest,
although I'm not sure that they come pre-marked - the package gave
instructions for the number of segments to collapse to achieve
resonance on 220 and 440. I think one was made by ADI and/or
Premier
but I can't be sure.

Most HT's can be modified to operate outside the amateur bands,
like on
GMRS, MURS, FRS, etc. But I don't like doing this without a
proper antenna.

You really shouldn't do it (well, at least, not transmit) even
_with_
a proper antenna. Very few, if any amateur-radio HTs are
certificated
for transmission on those bands, and using an "opened-up" ham HT to
transmit (even if you have a suitable GMRS license) is a rules
violation which could cost you your amateur ticket.

FRS and GMRS have very strict technical rules about the frequency
accuracy of their oscillators due to the tight inter-channel
spacings,
and it's likely that at least some ham HTs are too sloppy in design
(or too poorly calibrated) to hit the frequencies accurately.

--
Dave Platt
AE6EO
Hosting the Jade Warrior home page:
http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I
will
boycott any company which has the gall to send me such ads!

I for one take the easy way out on all bands, vhf hf etc.
Use "tuners". At least your protecting whatever rigs ouput
you have. It does'nt speak to efficiency that way, but I get
rather good results with my G6 VHF antenna on all modes and
on MARS freqcys also which are out of the HAM band limits.
HF same thing. MFJ diferential T tuner with roller coil gets
me anywhere I want to go from 3.5 mhz on down to 30 mhz.
Kokomo Joe


************************************************** **
* Ham KH6JF AARS/MARS ABM6JF QCWA WW2 VET WD RADIO *
* Army MARS State Coordinator for Hawaii *
************************************************** **


On Tue, 5 Apr 2005, JB wrote:

I agree. You run into the same problems that Public Safety radios
have to deal with. That is, trying to operate over a wide range
perhaps 150 -174 MHz with a high power radio. Certainly the 1/4 wave
is the best you can do to avoid shutdown of the radio.

For Dual-band 2m/440 operation and in particular when operating MARS,
a 1/4 wave 144 MHz antenna will provide a more satisfactory load at
UHF as well, although with a compromised pattern on those
frequencies.

One of the most frightening tests I performed with 2m/440 ham
antennas was that they were extremely sharp in bandwidth and resulted
in extreme SWR beyond -+ 2-3 MHz on either band.

Public safety personnel often don't understand how hams can have high
performance dual band antennas and they can't. Some suspiciously
consider a conspiracy. The simple answer lies in the frequency
coordination of the repeater frequencies on both bands, and the
narrow but coincidental sliver of frequencies we use for mobile
operation.

If you have a telescopic whip you are blessed. Carry a tape measure
and chart with you.

Of course there are other issues regarding MURS, GMRS and FRS that
are completely awkward and you might as well carry a real FRS radio
along with a Commercial radio with a bank devoted to the ham bands on
your bat-belt.

I contest the mentality that says you should "open up" a ham radio
for "emergency use only" because you compromise the emergency
situation by not using a radio up to the task. You can use a
"church-key" as a can opener, but if you are truly serious you will
pack a can opener.

Jim, ac6tk


"Dave Platt" wrote in message
...
In article ,
Bruce W.1 wrote:

Does anyone make a telescoping HT antenna meant to operate (1/4
wave)
over a broad band of frequencies with marking for those
frequencies?

I've seen one or two such on a dealer's table at a local hamfest,
although I'm not sure that they come pre-marked - the package gave
instructions for the number of segments to collapse to achieve
resonance on 220 and 440. I think one was made by ADI and/or
Premier
but I can't be sure.

Most HT's can be modified to operate outside the amateur bands,
like on
GMRS, MURS, FRS, etc. But I don't like doing this without a
proper antenna.

You really shouldn't do it (well, at least, not transmit) even
_with_
a proper antenna. Very few, if any amateur-radio HTs are
certificated
for transmission on those bands, and using an "opened-up" ham HT to
transmit (even if you have a suitable GMRS license) is a rules
violation which could cost you your amateur ticket.

FRS and GMRS have very strict technical rules about the frequency
accuracy of their oscillators due to the tight inter-channel
spacings,
and it's likely that at least some ham HTs are too sloppy in design
(or too poorly calibrated) to hit the frequencies accurately.

--
Dave Platt
AE6EO
Hosting the Jade Warrior home page:
http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I
will
boycott any company which has the gall to send me such ads!

On Tue, 05 Apr 2005 05:48:12 GMT, "Bruce W.1" wrote:

Does anyone make a telescoping HT antenna meant to operate (1/4 wave)
over a broad band of frequencies with marking for those frequencies?

Most HT's can be modified to operate outside the amateur bands, like on
GMRS, MURS, FRS, etc. But I don't like doing this without a proper antenna.

It would be simple enough to make a 1/4 wave telescoping antenna with
calibration marks for everything VHF and UHF, just extend it to the
right length. It would have an easy way to set it to the right length.
Does anyone make an antenna like this?

TNX,
Bruce AF8F

Why don't you get your own telescoping whip, attach it to a connector
for your radio, and using the formulas for frequency and antenna
lengh, mark the whip yourself? The only question is whether your handi
talkie input isn't already pre-configured strictly for the helio-wound
rubber duckie that comes with it.

For example, the rubber duckie that comes with my 2 meter Icom T2-H,
at 147 Mhz, has an swr of 3.0, and an impedance of just under 400
ohms, according to my MFJ 269 antenna analyzer. But the antenna works
fine on the handie talkie.

bob
k5qwg



bob
k5qwg

In article ,
Bob Miller wrote:

For example, the rubber duckie that comes with my 2 meter Icom T2-H,
at 147 Mhz, has an swr of 3.0, and an impedance of just under 400
ohms, according to my MFJ 269 antenna analyzer. But the antenna works
fine on the handie talkie.

You might want to try repeating the measurement with the MFJ 259 held
up beside your head as if it were an HT.

I've been told that HT duck antennas are often tweaked for best match
and lowest SWR when used in this position, with a significant amount
of capacitive coupling to the user's head. Measurements of a couple
of 'em with my 269 seemed to support this - they "read" a lot better
in a "typical HT use" position than they do if the analyzer is being
held out at arm's length.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

Dave Platt wrote:
In article ,
Bob Miller wrote:


For example, the rubber duckie that comes with my 2 meter Icom T2-H,
at 147 Mhz, has an swr of 3.0, and an impedance of just under 400
ohms, according to my MFJ 269 antenna analyzer. But the antenna works
fine on the handie talkie.


You might want to try repeating the measurement with the MFJ 259 held
up beside your head as if it were an HT.

I've been told that HT duck antennas are often tweaked for best match
and lowest SWR when used in this position, with a significant amount
of capacitive coupling to the user's head. Measurements of a couple
of 'em with my 269 seemed to support this - they "read" a lot better
in a "typical HT use" position than they do if the analyzer is being
held out at arm's length.

================================================== ======

That's the part that's difficult to measure. Some of my good HT
antennas that came with the radio, when tested alone on a good ground
plane, have lousy SWR. Yet these radios are fully capable of being
connected to an external antenna.

A perfect quarter wave is 36 ohms. Yet HT's are happy driving an
external 50 ohm antenna.

I do have a few telescoping antennas. This might be the best solution.
I was hoping someone made one built like a tape measure. A tiny SWR
meter that mounted between the HT and antenna would be a nice solution.

I'll admit I like to have the ability to at least jump over to the FRS
or the GMRS.