Dual-band mobile antennas in general have some phasing network that
allows the antenna to have a good radiation pattern (gain at the
horizon) on both bands.

They also need to have impedance matching on both bands.

Unfortunately, there's nothing universal about dual-band designs as far
as continuity or shorts or anything like that. Additionally, a search
on "Comet SSB-7" brings up some fairly unfavorable eHam reviews, many
of which mention DOA antennas, having to get replacements twice, etc.

There's not much you can do without knowing all the specifics about the
design, even then it would be tough to fix whatever's wrong; something
you can do is to check are the coax continuity to the NMO mount you're
using.

Dan

wrote in message
oups.com...
Dual-band mobile antennas in general have some phasing network that
allows the antenna to have a good radiation pattern (gain at the
horizon) on both bands.

They also need to have impedance matching on both bands.

Unfortunately, there's nothing universal about dual-band designs as far
as continuity or shorts or anything like that. Additionally, a search
on "Comet SSB-7" brings up some fairly unfavorable eHam reviews, many
of which mention DOA antennas, having to get replacements twice, etc.

There's not much you can do without knowing all the specifics about the
design, even then it would be tough to fix whatever's wrong; something
you can do is to check are the coax continuity to the NMO mount you're
using.

Dan

My Comet antenna went bad too, for grins and giggles I hooked my 2M radio up
to my CB antenna . SWR was good I hit all the local repeaters, Have tried it
on UHF and it works there too. Probably far from optimum performance but I
cant tell a lot of difference between it and the 2m half wave I have used. 1
antenna 3 bands. It works for me. What I think is going on is the bottom
hald of the center loaded CB antenna is about the right length for a 1/4 wl
2m antenna with the loading coil acting pretty much like a choke on 2m and
432. On UHF it probably looks lie a 3/4 wl antenna. Losses in the cable
probably help the match to the radio. What the heck , it works.

Jimmie D wrote:
wrote in message
oups.com...
Dual-band mobile antennas in general have some phasing network that
allows the antenna to have a good radiation pattern (gain at the
horizon) on both bands.

They also need to have impedance matching on both bands.

Unfortunately, there's nothing universal about dual-band designs as far
as continuity or shorts or anything like that. Additionally, a search
on "Comet SSB-7" brings up some fairly unfavorable eHam reviews, many
of which mention DOA antennas, having to get replacements twice, etc.

There's not much you can do without knowing all the specifics about the
design, even then it would be tough to fix whatever's wrong; something
you can do is to check are the coax continuity to the NMO mount you're
using.

Dan

My Comet antenna went bad too, for grins and giggles I hooked my 2M radio up
to my CB antenna . SWR was good I hit all the local repeaters, Have tried it
on UHF and it works there too. Probably far from optimum performance but I
cant tell a lot of difference between it and the 2m half wave I have used. 1
antenna 3 bands. It works for me. What I think is going on is the bottom
hald of the center loaded CB antenna is about the right length for a 1/4 wl
2m antenna with the loading coil acting pretty much like a choke on 2m and
432. On UHF it probably looks lie a 3/4 wl antenna. Losses in the cable
probably help the match to the radio. What the heck , it works.

rain water or condensation gets into the coil in the base...

Mark