High Efficiency Mobile HF Antenna?
 

Looking for suggestions for a high efficiency mobile antenna for HF.
I'd like to be able to cover 80-10m, and don't mind stopping to change
out sticks to change bands, so long as I don't have to retune each time.

I'll be mounting the base at bumper level off of the left side of my
pickup (offset from hitch mount), and can probably deal with 9 or 10
feet total height from the mount.

I have an Atas-120 currently mounted at the back edge of the roof, with
it's base at roof level, but am not impressed with it's performance and
am looking for something with higher efficiency. The convenience of
automatic tuning with my FT-857 is less of a convenience than I thought
it'd be, especially considering it doesn't seem to have good efficiency.

Any Ideas?

Thanks
--Rick AH7H

Rick Frazier wrote:
Looking for suggestions for a high efficiency mobile antenna for HF.
I'd like to be able to cover 80-10m, and don't mind stopping to change
out sticks to change bands, so long as I don't have to retune each time.

I'll be mounting the base at bumper level off of the left side of my
pickup (offset from hitch mount), and can probably deal with 9 or 10
feet total height from the mount.

I have an Atas-120 currently mounted at the back edge of the roof, with
it's base at roof level, but am not impressed with it's performance and
am looking for something with higher efficiency. The convenience of
automatic tuning with my FT-857 is less of a convenience than I thought
it'd be, especially considering it doesn't seem to have good efficiency.

Any Ideas?

The best 75m mobile antennas at the previous shootouts have been
either bugcatchers with top hats or screwdrivers with top hats.
Such antennas are about 12dB better than a 75m hamstick.
--
73, Cecil, W5DXP

"Cecil Moore" wrote in message
...
Rick Frazier wrote:
Looking for suggestions for a high efficiency mobile antenna for HF.
I'd like to be able to cover 80-10m, and don't mind stopping to change
out sticks to change bands, so long as I don't have to retune each time.

I'll be mounting the base at bumper level off of the left side of my
pickup (offset from hitch mount), and can probably deal with 9 or 10
feet total height from the mount.

I have an Atas-120 currently mounted at the back edge of the roof, with
it's base at roof level, but am not impressed with it's performance and
am looking for something with higher efficiency. The convenience of
automatic tuning with my FT-857 is less of a convenience than I thought
it'd be, especially considering it doesn't seem to have good efficiency.

Any Ideas?

The best 75m mobile antennas at the previous shootouts have been
either bugcatchers with top hats or screwdrivers with top hats.
Such antennas are about 12dB better than a 75m hamstick.
--
73, Cecil, W5DXP
Rick
I use a Tarheel screwdriver because the base is 4 feet long.
I operate the antenna at resonance and match the impedance to the
transmission line with a transformer.
This approach, along with a top hat for 80, produces the best field strength
I have been able to measure.
A Hustler base with a bug catcher works well also. For the higher bands the
Hustler resonators are fine.
Continuously loaded antennas like the hamstick work less well but are
broader in bandwidth.
A whip and tuner is the worst.
Cecil is quite correct about the shootouts.
73
H.
NQ5H

"high efficiency mobile hf antenna" that must win some kind of award for
the longest oxymoron in radio speak.

"Rick Frazier" wrote in message
...
Looking for suggestions for a high efficiency mobile antenna for HF.
I'd like to be able to cover 80-10m, and don't mind stopping to change
out sticks to change bands, so long as I don't have to retune each time.

I'll be mounting the base at bumper level off of the left side of my
pickup (offset from hitch mount), and can probably deal with 9 or 10
feet total height from the mount.

I have an Atas-120 currently mounted at the back edge of the roof, with
it's base at roof level, but am not impressed with it's performance and
am looking for something with higher efficiency. The convenience of
automatic tuning with my FT-857 is less of a convenience than I thought
it'd be, especially considering it doesn't seem to have good efficiency.

Any Ideas?

Thanks
--Rick AH7H

H. Adam Stevens, NQ5H wrote:
I use a Tarheel screwdriver because the base is 4 feet long.

I use a High Sierra screwdriver with an RV extension because
the base is 6 feet long. :-)
--
73, Cecil, W5DXP

Dave wrote:
"high efficiency mobile hf antenna" that must win some kind of award for
the longest oxymoron in radio speak.

Heh, heh, how about "relatively high efficiency"?

"high efficiency mobile hf antenna" that must win some kind of award for
the longest oxymoron in radio speak.

Why?
Among HF mobile antennas there those that have low, medium and high effciency.
It is acategory that is limited by some 13' in height and size of the car. One
that produces most signal would be even highest efficiency than the rest of
them. No?

Yuri, K3BU.us

Cecil Moore wrote:
Dave wrote:

"high efficiency mobile hf antenna" that must win some kind of award for
the longest oxymoron in radio speak.


Heh, heh, how about "relatively high efficiency"?

The low efficiency antenna is 1% efficient. The high
efficiency antenna is 2%. That's double the efficiency.
I wouldn't judge efficiency on the basis of a shootout unless
the results were measured in the far field.
73,
Tom Donaly, KA6RUH

Tom Donaly wrote:
The low efficiency antenna is 1% efficient. The high
efficiency antenna is 2%. That's double the efficiency.
I wouldn't judge efficiency on the basis of a shootout unless
the results were measured in the far field.

They were measured in the far field, a good 1/4 mile away.

OK, so how about a slightly different method of describing what I'm looking
for:

" an antenna with considerably higher efficiency than the ATAS-120 I now have
"

smile

--Rick

Dave wrote:

"high efficiency mobile hf antenna" that must win some kind of award for
the longest oxymoron in radio speak.

"Rick Frazier" wrote in message
...
Looking for suggestions for a high efficiency mobile antenna for HF.
I'd like to be able to cover 80-10m, and don't mind stopping to change
out sticks to change bands, so long as I don't have to retune each time.

I'll be mounting the base at bumper level off of the left side of my
pickup (offset from hitch mount), and can probably deal with 9 or 10
feet total height from the mount.

I have an Atas-120 currently mounted at the back edge of the roof, with
it's base at roof level, but am not impressed with it's performance and
am looking for something with higher efficiency. The convenience of
automatic tuning with my FT-857 is less of a convenience than I thought
it'd be, especially considering it doesn't seem to have good efficiency.

Any Ideas?

Thanks
--Rick AH7H

Well, then, Cecil and I have described a couple that generally out perform
other approaches.
Big screwdrivers.
73
H.
NQ5H

"Rick Frazier" wrote in message
...
OK, so how about a slightly different method of describing what I'm
looking
for:

" an antenna with considerably higher efficiency than the ATAS-120 I now
have
"

smile

--Rick

Dave wrote:

"high efficiency mobile hf antenna" that must win some kind of award for
the longest oxymoron in radio speak.

"Rick Frazier" wrote in message
...
Looking for suggestions for a high efficiency mobile antenna for HF.
I'd like to be able to cover 80-10m, and don't mind stopping to change
out sticks to change bands, so long as I don't have to retune each
time.

I'll be mounting the base at bumper level off of the left side of my
pickup (offset from hitch mount), and can probably deal with 9 or 10
feet total height from the mount.

I have an Atas-120 currently mounted at the back edge of the roof,
with
it's base at roof level, but am not impressed with it's performance and
am looking for something with higher efficiency. The convenience of
automatic tuning with my FT-857 is less of a convenience than I thought
it'd be, especially considering it doesn't seem to have good
efficiency.

Any Ideas?

Thanks
--Rick AH7H

Save your $$. I was in the same spot you are and went for the Tarheel and
the W4RT auto tuner box. $500 or so later, I A/B compared my old roof
mounted ATAS 100 against my full size Tarheel on the bumper and the ATAS was
so close on 20 and above, I could not tell the difference. On 40, the
Tarheel was a slight favorite. Of course the ATAS does not run 80.

Theory: mounted up higher the lower efficiency ATAS overcomes its shortfall
because it has lower ground losses than the bumper mounted larger antenna.
Some modeling I did with G4FGQ's MIDLOAD seemed to confirm that would be the
case.

Another way to consider it: Mobile operating is unique in that signals had
better be pretty strong to begin with or you won't hear the station over the
cab noise, QSB from moving past a truck and RFI from the cars around you.
To say the full size screwdriver is two S units better on 40 means nothing
because you couldn't understand an S2 signal on the full size either. If
the signals are strong enough, an S9 on the full size is just as copiable at
S7 on the ATAS and is enough to get the job done.
--
Radio K4ia
Craig "Buck"
Fredericksburg, VA USA
FISTS 6702 cc 788 Diamond 64

"Rick Frazier" wrote in message
...
Looking for suggestions for a high efficiency mobile antenna for HF.
I'd like to be able to cover 80-10m, and don't mind stopping to change
out sticks to change bands, so long as I don't have to retune each time.

I'll be mounting the base at bumper level off of the left side of my
pickup (offset from hitch mount), and can probably deal with 9 or 10
feet total height from the mount.

I have an Atas-120 currently mounted at the back edge of the roof, with
it's base at roof level, but am not impressed with it's performance and
am looking for something with higher efficiency. The convenience of
automatic tuning with my FT-857 is less of a convenience than I thought
it'd be, especially considering it doesn't seem to have good efficiency.

Any Ideas?

Thanks
--Rick AH7H

"Craig Buck" wrote in message

Another way to consider it: Mobile operating is unique in that signals had
better be pretty strong to begin with or you won't hear the station over the
cab noise, QSB from moving past a truck and RFI from the cars around you.
To say the full size screwdriver is two S units better on 40 means nothing
because you couldn't understand an S2 signal on the full size either. If
the signals are strong enough, an S9 on the full size is just as copiable at
S7 on the ATAS and is enough to get the job done.

Of course. The receiving s/n ratio *should* be about the same on
anything you use, being you have way more signal than you need with
even the worst antenna. Or at least on the lower bands. But that 2 s
units can mean a lot to whoever you are talking to, if the noise
levels are high. I wouldn't say it means nothing. Thats like switching
on an amplifier. MK