Just pulled the trigger on a Comet GP-9NC, wish me luck 😅

[WSEM262]

Hmmm...  now im thinking again.

I currently have my 50w repeater connected via 35ft of LMR600 to a GP6NC on a 30ft mast at 1350ft asl and surrounded by hilly terrain.

 

I wonder if the GP9NC would be better or worse than the GP6NC in this area ???

[BoxCar]

Stay with the 6NC.

[MarkInTampa]

5 hours ago, WSEM262 said:

Hmmm...  now im thinking again.

I currently have my 50w repeater connected via 35ft of LMR600 to a GP6NC on a 30ft mast at 1350ft asl and surrounded by hilly terrain.

 

I wonder if the GP9NC would be better or worse than the GP6NC in this area ???

I have both of these antennas. 30ft mast, 50ft LMR400. In my case, the GP9 worked better on VHF and the GP6 better on UHF. Don't know if it is the location of the antenna, the oak tree 20ft away or what but I had a better experience with the GP6 over the 9.

I dropped my mast to 15ft and the GP6 made it just fine though the Cat3/4/5 hurricane that hit me last week in Tampa. Don't have to worry about the oak tree....it didn't. Power is still down, no air conditioning sucks.

[BoxCar]

The GP9NC highest frequency is 450 MHz while the GP6NC's is 470 MHz. The 6 covers the GMRS frequencies while the GP9 cuts off below GMRS.

[MarkInTampa]

1 hour ago, BoxCar said:

The GP9NC highest frequency is 450 MHz while the GP6NC's is 470 MHz. The 6 covers the GMRS frequencies while the GP9 cuts off below GMRS.

The GP-9NC (GMRS/MURS) is rated 153-157MHz and 460-470MHz. The straight GP-9 and GP-9N (ham version) is rated 144-148 and 440-450MHz.

[WRYZ926]

And even the standard dual band version of the GP9 can work just fine on GMRS. Each individual antenna can and will vary. My GP9 has a SWR of 1.5 across the 467MHz portion and SWR of 1.7 on the 462 MHz portion. I am at 15 or less for 2m and 70cm.

[GreggInFL]

On 10/14/2024 at 3:13 PM, MarkInTampa said:

I dropped my mast to 15ft and the GP6 made it just fine though the Cat3/4/5 hurricane that hit me last week in Tampa. Don't have to worry about the oak tree....it didn't. Power is still down, no air conditioning sucks.

Ouch.  Sorry to hear that.  We lost power in central FL but only for ~ three days.  Hang in there.

[GrouserPad]

On 10/14/2024 at 4:59 PM, MarkInTampa said:

The GP-9NC (GMRS/MURS) is rated 153-157MHz and 460-470MHz. The straight GP-9 and GP-9N (ham version) is rated 144-148 and 440-450MHz.

I just got one of these antennas and the paperwork with it does not show it covering 467 MHz. Think it cut off at 465mhz. Has me wondering if maybe the newer gp9nc antennas aren’t purpose built for gmrs….anybody know? Ordered from engineering and their online showed it covering to 470mhz. . . Then my paperwork that came with my gp9nc said ham only. Ugh ? Wish I had an antenna analyzer to check it before I put this thing up. 

[Socalgmrs]

I’ve got a 9nc and it works amazing.  I was only getting 200miles with my 712efc and a 20w.  Now 250miles with the 9nc and 20w and even more hooked to my new 50w. 

[WRYZ926]

The GP-9 (PL259) doesn't say it covers GMRS in the paperwork either. But the SWR is 1.8 or less across all GMRS channels, 2m and 70cm. Others have tested their GP-9 antennas and the SWR was above 2.0 on GMRS. So each antenna does need to be checked.

[WRYZ926]

2 minutes ago, Socalgmrs said:

I’ve got a 9nc and it works amazing.  I was only getting 200miles with my 712efc and a 20w.  Now 250miles with the 9nc and 20w and even more hooked to my new 50w. 

Again, you live in an area that allows that. Most people will never see those kinds of ranges. Your range of 200+ miles in very unrealistic for the majority of people.

[MarkInTampa]

2 hours ago, GrouserPad said:

I just got one of these antennas and the paperwork with it does not show it covering 467 MHz. Think it cut off at 465mhz. Has me wondering if maybe the newer gp9nc antennas aren’t purpose built for gmrs….anybody know? Ordered from engineering and their online showed it covering to 470mhz. . . Then my paperwork that came with my gp9nc said ham only. Ugh ? Wish I had an antenna analyzer to check it before I put this thing up. 

The advertisement for the GP-9NC shows it as a GMRS antenna and covers 460-470MHz. The GP-9 and GP-9N (no C at the end) are ham only. The letter "C" is Comet's designation for the commercial band (kinda where GMRS resides) - not ham. The letter "N" means it has a "Type N" connector and the straight GP-9 is ham only with  a SO-239 connector. When I got mine, the bag it came in said it was GP-9N and they put on a tiny sticker with the letter "C" at the end of it. My guess is they didn't want to print up new packaging to add a letter. I don't remember what paperwork it came with though (ham or GMRS) but I didn't have to tune it.

[WRYZ926]

Yes the C does designate commercial which means that the antenna will work in the 2m business/MURS portion and the UHF business and GMRS. 

That being said, a lot of times, but not always, the GP-9 and GP-9N amateur band antennas will also work for GMRS. The only way to know is to test the SWR.

[LeoG]

Ya, I just got the CA712EFC and the "C" is just a sticker they put on.  1st time I bought the antenna I emailed the company and they said that's the way they do it.  2nd time I ordered the antenna it was the same.  No need to email the company, had already been through it.

[GrouserPad]

To update this: friend ordered the same antenna as me(gp9nc) from a different comet dealer. Both antennas come with the ham band paperwork and show the working frequency as 155mhz to 465mhz(close enough for gmrs of course) Both antennas had paperwork that stated "Ham bands only". Not a big deal at all but as a new buyer you would be slightly concerned thinking maybe you got sent the "other" gp9n available rather than the nca. Anyhow carry on. Thanks guys ya'll always offer tons of info to me so paying it forward with this post if anyone else comes across a similar concern.