Comet GP-15 tri-band Ham antenna

[ronhl]

Hi and Happy Holidays to all,
I was wondering if anyone out there has any experience with this antenna when used with a scanner or communication receiver?
Does it work well down at the 30 - 50mhz band? How does it perform at say 155mhz and say 460-482mhz.
Im currently using a Diamond d130 discone up above the roof and thinking of changing to get better low band performace.
thanks

 

[Dubbin]

Are you looking for something to transmit with too?

 

[fineshot1]

Google is your friend

Read for yourself.

http://www.eham.net/reviews/detail/383

 

[blueangel-eric]

Read for yourself.

http://www.eham.net/reviews/detail/383

i read two pages worth on there and they don't do reviews on how it works for receiving other bands.

 

[fineshot1]

i read two pages worth on there and they don't do reviews on how it works for receiving other bands.

Well - its probably tuned for 146Mhz/445Mhz/52Mhz and its a large gain antenna so it will most likely do well on low band 30-50, vhf-hi 148-174, and uhf 450-470 but the only way to know for sure is to try it. If you use good 50ohm impedance cable and proper connectors and mount it up high enough it should work well for you. Also - make sure its well grounded, dont want to attract lightning. Good luck & happy holidays...

 

[Skypilot007]

I have a comet GP6 and receives quite well on the 30-50 mhz range. I do have it mounted quite high so that helps.

 

[triryche]

Well - its probably tuned for 146Mhz/445Mhz/52Mhz and its a large gain antenna so it will most likely do well on low band 30-50, vhf-hi 148-174, and uhf 450-470 but the only way to know for sure is to try it. If you use good 50ohm impedance cable and proper connectors and mount it up high enough it should work well for you. Also - make sure its well grounded, dont want to attract lightning. Good luck & happy holidays...

Not Entirely correct.

Dual-band and Tri-band ham antennas are designed with gain in specific bands and generally are deaf out side of the nearby frequency design. My GP-6 and GP-9 are DEAF on low band, UHF aircraft, and 800 MHz. The GP-15 will perform ok below 50 MHz for reception purposes however you will see occasions where a scanner designed for all bands can and will get overloaded by a higher gain antenna like this. I am using a GP-6 for scanning VHF/UHF and while it provides some slight gain over a discone or a scanntenna, it also drags in pager intermod and adjacent channel interference that the scanner antennas do not.

 

[fineshot1]

Not Entirely correct.

Dual-band and Tri-band ham antennas are designed with gain in specific bands and generally are deaf out side of the nearby frequency design. My GP-6 and GP-9 are DEAF on low band, UHF aircraft, and 800 MHz. The GP-15 will perform ok below 50 MHz for reception purposes however you will see occasions where a scanner designed for all bands can and will get overloaded by a higher gain antenna like this. I am using a GP-6 for scanning VHF/UHF and while it provides some slight gain over a discone or a scanntenna, it also drags in pager intermod and adjacent channel interference that the scanner antennas do not.

Mike - I think I covered all the bases when I included "most likely" and "mount it up high enough it should work well for you" in my statement. The OP never mentioned "UHF aircraft, and 800 MHz" so not sure why you even brought that up, and yes I am well aware of what a high gain antenna can do to the front end of a scanner but that was also not part of this discussion since it is a hypothetical and the OP is not in that situation. I have been working with VHF, UHF and microwave gain antennas long before you had your ham ticket, so not sure why you think you felt the need to say "Not Entirely correct" when nothing I stated was incorrect.

 

[triryche]

He asked about low band and I stated my experience was they were DEAF when you drop below the spec frequency range! I included extra information about other bands for future reference to anyone who may be interested. Geez, get off your high hourse already!! :roll:

 

[fineshot1]

He asked about low band and I stated my experience was they were DEAF when you drop below the spec frequency range! I included extra information about other bands for future reference to anyone who may be interested. Geez, get off your high hourse already!! :roll:

Not on any high horse here. I simply do not appreciate it when hams(its always hams that seem to do this) feel the need to make corrections where none are due. Your choice of words was poor. Instead - you could have said "I'd like to add" or similar phrase.

Anyway, ronhl to get back on topic - the performance from 30-50 should be ok at least.
Its got to be better than what you have now(a discone). The further away from 50(going lower in freq) you get reception will get worse as you move away from the range the antenna is tuned for. I am sure you realize that. Also if you do run into strong signal overload you can always design & build or purchase a filter such as par electronics makes to reduce the problem....good luck & hope it works out....

 

[kb2vxa]

The Diamond discone isn't for 6M or Lo band but this one is;

The Comet DS150S discone antenna receives solid from 25 to 1500 MHz! It can also be used for transmit on 50, 144, 430, 900 and 1200 MHz ham bands (under 100 watts).

I'd say from experience it's pretty much the same receive wise as the one you have in mind except for having unity gain on the ham bands as opposed to the vertical having it's rated gain on them. One thing to be wary of is that word "solid" being ambiguous at best, outside the ham bands both antenna's frequency response curve looks like a roller coaster and they're pretty deaf on 800MHz.

Since the only confirmed data available relates to the ham bands the only way you can determine which is "better" for use outside them is by making a side by side "A-B switch" comparison. Take what these guys here say with a grain of salt, they haven't made any sort of serious scientific tests on anything yet or at least haven't published any test data.

 

[N1BHH]

Not on any high horse here. I simply do not appreciate it when hams(its always hams that seem to do this) feel the need to make corrections where none are due. Your choice of words was poor. Instead - you could have said "I'd like to add" or similar phrase.

Anyway, ronhl to get back on topic - the performance from 30-50 should be ok at least.
Its got to be better than what you have now(a discone). The further away from 50(going lower in freq) you get reception will get worse as you move away from the range the antenna is tuned for. I am sure you realize that. Also if you do run into strong signal overload you can always design & build or purchase a filter such as par electronics makes to reduce the problem....good luck & hope it works out....

Actually it's more likely stubborn hams who think they know it all that gives the rest of us a bad taste in our mouths.

That antenna does quite well as do many of the other multi-ham band antennas. I use a NMO-2/70 at home on a mag-mount for a scanner antenna and it works quite well. It doesn't have super signal reception on low band, but it suits me just fine. It's always best to put antennas up as high as possible. If you can't get to the roof, then the A/C is suitable, at least in my case.

 

[kb2vxa]

"Actually it's more likely stubborn hams who think they know it all that gives the rest of us a bad taste in our mouths."

Speak for yourself, I don't put them in MY mouth.

I used a 144/220/440 tri band antenna on my scanner and it worked well except for being stone deaf on 800MHz. I don't monitor Lo Band so if it received it or not really didn't matter.

This is a pointless debate, like I said try it yourself and make an A-B comparison if you want a satisfactory answer as I anticipated this thread falling into the abyss of mindless oneupmanship.

 

[ronhl]

Comet GP-6NC Dual Band instead of the tri-band GP-15

Thanks for all the posts but I think I may of found what Im looking for instead....
Its specifically TUNED for the police/fire - vhf hi / uhf bands vs. the ham bands with excellent gain figures
Ill have to give up on the vhf 30-50 mhz low band coverage and also have to special order it but thats ok with me.
I really like the specs on this puppy, see below......

GP-6NC
VHF/UHF Dual Band Antenna
1.5:1 or less SWR: 153-157/460-470MHz
Gain: 6.5/9.0dBi
Max power: 200 watts
Length: 10 ft 2 inches
Weight: 3 lb 8 oz
Connector: N-female
Construction: Two piece white fiberglass
Max wind speed: 112MPH

 

[Highpockets]

Hi and Happy Holidays to all,
I was wondering if anyone out there has any experience with this antenna when used with a scanner or communication receiver?
Does it work well down at the 30 - 50mhz band? How does it perform at say 155mhz and say 460-482mhz.
Im currently using a Diamond d130 discone up above the roof and thinking of changing to get better low band performace.
thanks

When I sold all my ham gear, I left the gp15 up on a 30' mast, I tried it on my bc780xlt, it works pretty good on vhf, uhf and isn't too bad on 800, it does the job for what I want to listen to. I don't listen to anything in the 30-50 band. I like it because it's only 7'11" give or take and light weight, doesn't move around to much in high winds.

 

[Sparkletron]

GP-15 is deaf below 6M

Sadly, my experience is that the GP-15 is deaf below the bands it's intended for. I did an A/B comparison with a VHF J-Pole on SW and the difference was unequivocal; there's something about the GP-15's design that just filters out everything from 80M to 10M. Honestly my body can tune HF better than this antenna. It's a shame, because I was hoping to use the GP-15 as a general RX antenna, even if it wasn't designed for that. Those of us living in HOAs don't always have the luxury of sprouting antenna farms...