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General >> Rally >> Typical 2m rally frequencies?
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Message started by dtompsett on 11/13/4 at 11:41:03

Title: Typical 2m rally frequencies?
Post by dtompsett on 11/13/4 at 11:41:03

I just picked up my first radio, and a Larson NMO mag-mount antenna.

The antenna needs to be cut to provide the best length for the commonly used frequencies. Since I will most often be using this radio with rallying, i'm wondering what are the most typical frequencies used at events?

Title: Re: Typical 2m rally frequencies?
Post by John_Vanos on 11/13/4 at 12:27:31

I beleive I cut mine to 146mhz length, that is mostly in the middle of typical frequencies

Title: Re: Typical 2m rally frequencies?
Post by dtompsett on 11/13/4 at 12:45:16

ok... thanks john

Title: Re: Typical 2m rally frequencies?
Post by AnthonyT on 11/13/4 at 18:15:06

The antenna needs to be cut??
oh!oh?
Is this the case for all 2m magmount antennas? What about if it's a dual band?
I think I've got some more reading to do.

Title: Re: Typical 2m rally frequencies?
Post by RyanHuber on 11/14/4 at 00:19:05

With a dual bander you may not have to cut it, it'd likely depend on the antenna model, etc. It'd be in the instructions. As for cutting it, remember, we don't operate under 144.500 as that's mainly for data. We tend to be mostly between there and 147.500, and remember, the most used simplex frequency in Ontario rally is 146.580. That said, if you cut it for the middle of the band, it'll work just fine within the band, just be less efficient at the far extremes. Now, if the antenna was going to be used exclusively for packet or something along those lines, then of course you'd tune it for around 144.250.

Title: Re: Typical 2m rally frequencies?
Post by dtompsett on 11/14/4 at 14:30:31

it's been cut for 146.000 (remove an inch).... if I find i get poor Rx and Tx, I may cut a little more and take it to 147.000

Title: Re: Typical 2m rally frequencies?
Post by nhibbert on 11/14/4 at 16:59:50

I cut an inch off my Larsen, as per the sales guys advice, and it works great.

Title: Re: Typical 2m rally frequencies?
Post by Craig_Hamm on 11/14/4 at 18:09:10

The way to really do this PROPERLY is to find somebody with a SWR (standing wave ratio) meter. You want a SWR near 1 for max efficiency I believe.

As for the frequencies, it's all 2m band, and the band is THAT wide (4 in 146, 2% avg. relative bandwidth), and all the frequencies are listed in the 'band plan' in your Basic Guide, as well as online. Keep that handy, otherwise you may pick a simplex frequency some day and find you're stomping all over somebodies data packets, amateur satellite, or whatever.

I'm no radio guru, but try not to restrict your use to rally on 2 or 3 days of the year, and other times not know what you're doing, p-ing off knowlegable users. It's even annoying at rallies like Tall Pines, where there's so MANY radios out there, it can take only a few people to really mess things up sometimes. Just a bit-o-friendly advice to be careful with the new toy.

Bring the radio manual with you, too! You might find a version of it online. Download it, and print it off. Keep the original one in your files. I still use my manual occasionally out in the field.

What's your call Doug?

Craig

ps - of course, you know by Murphy's Law this means I'll be the guy out there sitting on the PTT now!

Title: Re: Typical 2m rally frequencies?
Post by dtompsett on 11/14/4 at 21:03:17

Hey craig... i'm definitely planning on bring my manual with me to pines!

My call is ve3tdn