Frequency Choices
 

Hello all,
After being out of this wonderful hobby for a long time, I am finally able to get involved again. The last time I bought a radio system was before the big change.
I was wondering about the pros and cons of the different frequencies. I hope I haven't struck a nerve with anyone here.
All opinions are appreciated.


Semper Fi

Adam

RE: Frequency Choices
 

Good question, I am kinda interested in an answer as well. I bought my radio gear (JR XP662) at the same time I bought my plane and everything else a while back, but no one really explained if there was a reason for picking a specific channel, or why. I know it is prudent to see what channels the guys you fly with are on, but other than that, I'm in the dark as well.

RE: Frequency Choices
 

If you will be flying with a club ask for a list of the frequencies and number of users on each. Then you can pick a less used frequency to avoid waiting for the pin to become available when you fly. You might also be able to learn if there are any problem frequencies that should be avoided in your area.

RE: Frequency Choices
 

Adam,

The one and only reason why I picked the channel I am on is that no one else in our club was on that same channel. This allows me to not have to worry about shooting down someone and basically allows me to fly whenever I want. Our club puts out a list once a year that shows who is on which channel.

It will bite if someone joins the club on the same channel in the future. I do wish JR had a 9303 that was synthesized so that I could pick whatever channel was available at any given time.

RE: Frequency Choices
 

Also consider which band has the most freqs on form your club and go with the fewr side. (Low band or High) Also remember if you ever want to change freqs , you need to stay within the side your already on to avoid problems. You can't cross over from low to high or reversal.

RE: Frequency Choices
 

JR doesn't have low or high bands--that's a futaba deal. Remember, though, the radio is supposed to be sent in for the frequency to be changed!

RE: Frequency Choices
 

One other note... I know several people in my club have experienced this, and I have heard of others having it too... For some reason, there seem to be a lot of complaints about channel 20... In general it seems to take a lot of hits and have some sort of interference... Not really sure though, but you may want to avoid it just to be on the safe side...

RE: Frequency Choices
 

Channel 20, that sounds like it may be a location thing. I had it on my first radio and where I fly I had no problems. I use 31 now and still no problems, both radios are/were JR

RE: Frequency Choices
 

I picked my freq just based on what channel other guys fly at my club. I watched the freq pin board for a couple of months after I joined, and picked a freq that no one ever used.

However, if you could pick any channel, hear are some things I thought about...

Futaba RXs are center tuned to high and low bands, so if you pick the channel in the dead center of those bands, you'll likely eek out a little more sensitivity. Most other brands of RXs are going to be center tuned in the middle of the band, so picking the center channel freq of the entire band would put you dead center. The idea here is that you're picking the channel that the RX is factory tuned to, instead of sending your RX in to have it retuned to a channel you selected.

With that said, I doubt most fliers would be able to notice a difference, and I've even seen guys fly Futaba RXs tuned for high band fly with a low band xtal in them without a problem.

RE: Frequency Choices
 

If you are concerned about the channels and don't want to spend the BIG $$$ for a transmitter with a module, check out the Tracker III from Polks.

I have a Tracker II and really like it. It is fully synthesized on both the transmitter AND receiver and the transmitter has a built in scanner. If the scanner detects interference on your channel it will not allow the transmitter to generate a signal. It is also compatible with both the Futaba/Hitec receivers as well as the Airtronics/JR receivers.

The Tracker III (8 channel ) is physically a little smaller than the II and now has a buddy box port among the new features.

I THINK the transmitter, receiver, 900 mah batteries and 1 servo are ABOUT $300

RE: Frequency Choices
 

I took channel 13 with my Futaba....I'am the only one.....never have to share a pin. Everybody else is superstitious!!;)

RE: Frequency Choices
 

Some good advice from several people. My advice would basically be a recap of theirs, but I do have a question for everyone.
My local club has a long standing rule against flying on any channel that is within two channels of one that is in use. I used to be a radio technician in the service, so I understand the reason behind this rule, and since the club is relatively small (around 30 members) it doesn't create a big problem, but I was wondering if it's really necessary with today's narrow-band radio gear. I know that years ago, radios had a good deal of "drift" so you could actually be on one channel, but be "dirtying up" the channel above and/or below you. Just curious...

RE: Frequency Choices
 

One of my planes is on channel 35, and a good friends is on 36... I've often flown at the same time standing a foot away from him and we have never had any problems... Many people in our club fly on adjacent frequencies and to date I don't believe we've ever had a problem. As you said, with todays equipment, unless you have a serious problem with your transmitter or xtal, your not going to interfere with any adjacent channels...

Just for kicks, you outta bring this up at the next club meeting you have... Since you used to be a radio tech you'll appreciate this... From the standpoint of "noise" that's generated, you will find there are probably much more "crap" being spit out on at least the first and second harmonic of the frequency, maybe even the third, than there is on the frequencies of the next adjacent channels... ;)

RE: Frequency Choices
 

back in the days prior to the current narrow band gen of equipment, that was a concern. isn't any more.

RE: Frequency Choices
 

Okay, now I'm a bit confused... If I want to change channels on my 662, I have to send it in? I cant just change TX and RX crystals myself? [X(]

RE: Frequency Choices
 

Legally according to the FCC you cannot change the crystal transmitter crystal yourself. You can change the receiver crystal at anytime you see fit

RE: Frequency Choices
 

Rx, yes you can do on your own. Tx needs to be changed by an authorized service person. This is an FCC requirement to be sure it's properly tuned.

RE: Frequency Choices
 

With a good FM or PCM receiver you shouldnt have any trouble being 1 frequency apart. We fly foamies standing shoulder to shoulder on 52-53, 35-36 and have no problems whatsoever. Now some of the guys that have the cheaper single conversion mini receivers have had some problems but its an exception not the rule. At our field we fly whatever, whenever PCM or FM, 2 chanels 1 number apart and other than channel 14 we have no problems. We arent sure what exactly is the source of interference but as far as I know, no one flies on 14.

RE: Frequency Choices
 

Ah, I got it now, thanks!

RE: Frequency Choices
 

inside our frequency pin cabinet, we have a freq chart. It shows who is on what channel, all the radios that they own. If/when someone buys a new radio on a new freq, they update the chart, and the master of the list posts a new list monthly.

sorry for the format, but here is what I pulled off the excel spreadsheet that I got recently of the current survey.

Channel
00 01 02 03 04 05 06 07 08 09 <--- HAM Band (50mhz)
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
51 52 53 54 55 56 57 58 59 60

People on the freq
1 1 1 0 0 1 0 0 1 1
3 1 4 1 3 4 4 8 1 7
7 2 1 1 3 7 1 4 2 6
2 3 1 5 4 2 2 5 2 7
1 7 5 6 2 3 0 3 2 6
3 7 2 5 1 2 4 1 3 5


***edited this in***

I am now the only one on 47, hence the reason for wanting the list locally, so I could figure out what to move from, chan 52 was WAY over populated!

RE: Frequency Choices
 

I have seen at our field, chan 50, 51, 52, and 53 in the air at one time. We only allow 4 planes up at once, and the ppl on those chans, including me at the time, are regular fliers. We have never had a glitch, yet.

RE: Frequency Choices
 

[/quote]

I have seen at our field, chan 50, 51, 52, and 53 in the air at one time. We only allow 4 planes up at once, and the ppl on those chans, including me at the time, are regular fliers. We have never had a glitch, yet.
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I had to cancel my first attempt at a reply. I caught myself giving a long dissertation on old radio technology:(. Let's just say that todays radios are much better than the old ones. We have some people in our club that have been flying for more than 50 years (not a typo). They founded the club in the early 60's. Back then, the rule probably was a good one and it has outlived its usefulness, but I'm new to club, so I'm not going to make waves over something that will rarely even come up. Now if we can just get our membership up to where it becomes a problem............

RE: Frequency Choices
 

Hey Rich D,
Question about your frequency spreadsheet; what do the numbers 00 through 10 represent? The channels set aside for RC flying are 11 through 60.
Dennis-

RE: Frequency Choices
 

He has 00 thru 09, there is no 10... those are the 50MHz Ham band channels...

http://www.modelaircraft.org/comp/frequency.htm

RE: Frequency Choices
 

Of course, I didn't take a minute to stop and think. :eek:
Dennis-