I am looking for a HF-optimized mag-mount active antenna, but
apparently NOBODY MAKES THEM! If you want something MIL-spec running
on 24Vdc, have $1000 to burn and you don't mind having to drill holes
in your car, and to cope with humonguous signals above and below HF,
you're well served. But have you ever seen a ready made model (or
even construction plans) for an antenna with these features?



ACTIVE SW ANTENNA FOR MOBILE - SPECIFICATIONS

- coax-powered impedance matching preamplifier

- short whip (say 4 ft), collapsible

- optimized for 3-30 MHz coverage, with
dampening of both FM and AM / Medium Wave
(never seen one, not even plans for one,
and both bands are a big overload problem in my area)

- 12 Vdc (not 24, as in MIL grade models)

- priced MUCH less than $500-1000 (as MIL grade models cost)

- MAGNETIC MOUNTED (not requiring HUGE holes in the car body,
as professional models do)



I talked to a ton of people, and came up with absolutely NOTHING. I
received suggestions about a number of models, but none fits the
description. For example:
- Radiomaster: price OK, but not mobile, no AM dampening.
- MFJ-1024: price OK, useful attenuator, but not mobile, no AM
dampening.
- Sony AN-1: old model, discontinued, not mobile, no dampening on
either FM or AM, no attenuator.

Is there something I have missed? If this darn thing really doesn't
exist, do you have any suggestions on who to pester to have one
designed and produced?
- suppliers?
- distributors?
- major broadcasters?
- the Digital Radio Mondiale consortium?

Finally, does anyone know of a 12-volt whip matching amp design,
HARDENED AGAINST AM/FM OVERLOAD? I am not that good at RF design, and
it would take me forever to come up with a workable design.

TIA, hope this gives someone food for creativity.

Spammy

SpamLover wrote:
I am looking for a HF-optimized mag-mount active antenna, but
apparently NOBODY MAKES THEM! If you want something MIL-spec running
on 24Vdc, have $1000 to burn and you don't mind having to drill holes
in your car, and to cope with humonguous signals above and below HF,
you're well served. But have you ever seen a ready made model (or
even construction plans) for an antenna with these features?



ACTIVE SW ANTENNA FOR MOBILE - SPECIFICATIONS

- coax-powered impedance matching preamplifier

- short whip (say 4 ft), collapsible

- optimized for 3-30 MHz coverage, with
dampening of both FM and AM / Medium Wave
(never seen one, not even plans for one,
and both bands are a big overload problem in my area)

- 12 Vdc (not 24, as in MIL grade models)

- priced MUCH less than $500-1000 (as MIL grade models cost)

- MAGNETIC MOUNTED (not requiring HUGE holes in the car body,
as professional models do)



I talked to a ton of people, and came up with absolutely NOTHING. I
received suggestions about a number of models, but none fits the
description. For example:
- Radiomaster: price OK, but not mobile, no AM dampening.
- MFJ-1024: price OK, useful attenuator, but not mobile, no AM
dampening.
- Sony AN-1: old model, discontinued, not mobile, no dampening on
either FM or AM, no attenuator.

Is there something I have missed? If this darn thing really doesn't
exist, do you have any suggestions on who to pester to have one
designed and produced?
- suppliers?
- distributors?
- major broadcasters?
- the Digital Radio Mondiale consortium?

Finally, does anyone know of a 12-volt whip matching amp design,
HARDENED AGAINST AM/FM OVERLOAD? I am not that good at RF design, and
it would take me forever to come up with a workable design.

TIA, hope this gives someone food for creativity.

Spammy

Your best bet is likely to be creating your own.

You could use a CB or 10 meter ham magnet mount antenna with an external
amplifier.

Likely sources for good preamps are Arr, and any of the milspec preamps
that turn up at hamfests or on ebay from time to time.

I'm partial to the milspec ones. I've had good results with ones made
by Avantek, WJ, and Norlin/Applied Communications/Aiken.

Many of these will call for 15vdc, but I've had good luck running them
with less.