ooooo

All of the above is just Moot to me. I have a Futaba 6XAs from the Hobby Store on Ch. 26. Three yrs now. I'm changing to channel 15, 18....and get it....ch 41. Never had a problem...never caused a glitch on anyone else's radio.....etc etc.
I will continue to do so for years to come until I change radio I guess. I see no problem.

tadawson

KB9STD -
If all transmitters are so precisely R/L/C tunes in the output, please explain how things like HT's and newer ham gear requires NO tuning and goes up to 100watts? I am writing this sitting in front of a Yaesu FT847, which will cover most all frequencies from about 3MHz to 450MHz, no tuning required. Most of the tuning needs were on older tube based equipment - it is pretty easy to get a clean transmitter across a band, especially at low powers, like the R/C stuff. While I do not disagree that the law is the law, I do take exception to those who automagically claim that the law exists because the stuff can't meet specs without retuning - I think that may very well be false. I think the mfg. may well do nothing more than to put in the new crystal and look at it on a monitor to make sure it is in spec, and then ship it. After all, if all they have is the module, they can't exactly tune it anyhow, since the rest of the radio and antenna are not present. Not that there will be much variance, but there will be some . . . prehaps more that that introduced by the crystal change. I don't mean to throw fuel on the fire here, and advocate an illegal practive, but am just debating the technical issues, which I think are potentially being misrepresented.

- Tim, N8EAU

strato911

Then stay away from my flying field - you are NOT welcome here until you change your attitude.

KB9STD

My Feedback: (1)

tadawson, I admit that I have to agree somewhat.The "Output" circuits don't need to be tuned as precisely as the "Oscillator.However,I think it is central to the equation that the Yeasu FT 847 is not crystal controled.It has a PLL frequency oscillator.There is a crystal,and it's circuits are tuned for that crystal,But the same crystal is used(and oscilates at the same frequency) regardless of the output frequency.The amateur HF transmitter is also not subjected to the same "NarrowBand" requirements as an RC transmitter.AND the potential resusts of interference are no where near as serious.

Ladyflyer

My Feedback: (2)

. See what I mean when I say TRYING NOT to understand .
They keep going back to TUNING . They have failed to read the threads and/or the concepts are totally outside their grasp (very likely)[:-] .


. Tuning is only a minor part of the equation. The people on the AMA frequency committee worked with the FCC to get us the use of this valuable bandwidth . The FCC agreed with these provisions. Complying with the rules and laws is not too much to ask from any reasonable person

ooooo

Winnepeg eh! Pull the corn from up your butt mahn. You guys can't fly I hear. Muaghahahahaha

tadawson

KB9STD -
I agree here. On the Synth stuff, the 'base" oscillator crystal is a given, so typically it won't drift. The issue I hear folks saying are things like "without a retune, you won't get full power" and "the signal will be wider and dirtier". Those are the things that CANNOT occur if the finals are broadband - the worst case will be an out of tolerance crystal that has to be "warped" in. If quality control is good, this may not even be needed - witness Multiplex, as discussed in this thread. I do not imply that I KNOW that the RC transmitter amps are broadband, but in light of current technology and the low power output in RC, it would suprise me greatly if they were not. I imagine that the "factory retune" consists of nothing more than putting in the new crystal and verifying output frequency on a monitor, and nothing more. If it is off, bin the crystal and try again . . . . I have not opened a module to look, but I doubt if there are too many tunable components in there, especially in light of all the handling our radios get. Movable components just ask to be changed if the radio is jarred or dropped . . . .

- Tim

Whyes

[quote]ORIGINAL: Ladyflyer

. See what I mean when I say TRYING NOT to understand .
They keep going back to TUNING . They have failed to read the threads and/or the concepts are totally outside their grasp (very likely)[:-] .


.Tuning is only a minor part of the equation. The people on the AMA frequency committee worked with the FCC to get us the use of this valuable bandwidth . The FCC agreed with these provisions. Complying with the rules and laws is not too much to ask from any reasonable person





I think I see what she means ,
They ARE trying Sooooooo hard NOT to get it .

tadawson

I think everyone DOES get it. The issue at hand being discussed I think revolves heavily around the fact that legislation frequently has no basis in technology or fact, or perhaps, is based on outdated fact. So, the discussion, at least as I see it, is regarding whether or not the FCC regs really protect us from anything, and frankly I have my doubts. However, like any other law, stupid or otherwise, it is still law and should either be respected or repealed and outdated.

- Tim

alanc

well, ive read this thread, and i am amazed, first greetings from the uk, i was told you guys(n gal) had dedicted xtals, tell, me, if you have a shared site, glider and power, do you have differant sets of radio for each, sounds like the hobby shops are on to a good thing! over in the uk, for your information, we are on 35mhz, on 10 kc spacing we swap xtals ALL THE TIME when i fly at an event, there is ALWAYS a scanner, frequency control is high on the list over here, ever since a death, caused by mis-management of the frequency board at a uk field, nothing to do with the xtal selection, granted, at most of the shows we fly at, there is 20 kc spacing
but it does not alter the fact that we swap xtzls, we have been brought up to respect our xtals, all model store will sell you any channel you want, 30years ive been flying, NEVER a xtal glitch, ive got about 20 sets, we fly at the moment the ff8, my son flys the wc11 airplanes range from ity bity things, to 42%cap and extra, what i am trying to say here, is that you are being conned, a rule has been made, you have been brought up on it, so you believe it, i know bugger all about electronics but i dont know anything about tvs either, but i know how to work one, all you need is frequency control self discipline, and a safe cushioned box, to put your xtals in all this crap about the xtal being tuned to the tx is BS i will have a word with the uk importers of futaba and ask there opinion i know gary at ripmax, i fly with him, tell me, if we do it, why cant you? have a great 2004 season,

Whyes

The rules are just as much ,or MORE for the protection of OTHERS . No ,very many still do not get it. The rules are here for reasons . the fact so many don't comprehend the reasons does not change the need for the rules .

It HAS been discussed often and from the continuation of comments regarding SPACING and TUNING it seems obvious many folks still don't understand the SHARED aspect ,where we are 10 KHz away from licensed industrial users that cannot tolerate interference from outside. So far it has been working very well.
It is really nice to have nearly 100 frequencies to use here in the US . I can't think of too many other places on earth where RC has that many channels to choose from. The rules are very easy to live by and they DO have good reasons behind them.
We have synth modules , Amateur Radio and CB frequencies where an operator may ,himself change frequency as often as it takes to make him or her happy . Not exactly as totaliterian as in some OTHER regions on the planet.

strato911

Because the law says we can't. The law was written, because we are SECONDARY users of our frequency (72Mhz). The FCC doesn't care if our Tx's crash someone else's plane. THEY DO CARE if we cause interference for the industrial users who pay big $$$ for the use of their 72Mhz frequencies.

alanc

AFTER PLACING THIS QUESTION ON R/C FLYERS.CO.UK THE ANSWER IS CLEAR, YOU SHARE THE 72 MHZ BAND WITH INDUSTRY also, it appears that if we on 35mhz have a tuneing problem, then that problem is 2 fold on 72 mhz, so, it is neccasary for you to have your gear in tip top working order, but, is the industry transmission checked? happy flying fly high, fly safe

Montague

If you are asking "does anyone check to make sure the industrial users are within their limits", the answer is likely "sort of". Their license specifies what frequency they are on and so on. But if they overlap on to our channels it's our problem, not theirs. That's why they are "Primary" and we are "Secondary". They can shoot us down, but we can't mess with them. I'm under the impression that if they were really blasting all over the place, you can call the FCC and they can be inspected to make sure they are within their limits. But it's not worth the effort.

At my field, there are 3 pair of channels that are not allowed. That's because there are 3 commerical transmitters fairly close to our field. If they were farther away, it wouldn't be a problem, but where they are, their sidebands are wide enough to cause some hits on the adjacent RC channels. (Though they aren't THAT close, some guys have flown on the banned channels before they were banned with no problems, while other guys got nothing but glitches on those channels). Also, at least one of them isn't on all the time, so it's possible to fly quite a bit on the channel with no problems. But when it's on, the channels are not useable.

Whyes

Thank you Kirk,
Of course the industrial users utilize type accepted ,professionally maintained equipment. The frequencies are ASSIGNED by the FCC and COORDINATED for MINIMUM chance of interference.
AND ,as you said THEY ARE PRIMARY USERS, we are SECONDARY,UNLICENSED users.
BY LAW secondary users must ACCEPT ANY interference from PRIMARY users, SECONDARY users MUST NOT generate interference and can be held responsible for any injury or damage caused by their interference .
Don't like the those rules you can get a HAM license and become a PRIMARY, licensed user yourself ! Not all bad eh ?

We may be a bit behind the tech curve here in the colonies but we still figger tings ouwt .

smokingcrater

and to add even more the discussion... someone mentioned channels that are unflyable due to interference. this might not even be the result of a frequency even close to RC freq's, if you have a radio tower blasting out 100,000 watts at 550 khz (am radio broadcast), it is going to overload the frontend of any nearby rx, no matter what freq you are on. that antenna connected to the rx is great at receiving every radio emission, it just prefers ones it is tuned for but enough power makes that null and void... (a cell tower close to my field occassionally causes problems, and that is 850-900 mhz and 1.9 ghz)


Ryan
kc0lmo

alanc

interesting, the fact that the flyers are secondary users, and the primary users can, in efect cock there noses at you, i wonder, how many flyers are there in the states, and how many industrial users, i would imagine evry town/city has a model flier, if they have 2, or even four,never mind a larg club, would that not make the flyers the primary user? or is it a MONEY THING

Whyes

Ever had a problem when swapping crystals ? NOPE ,I DO IT ALL THE TIME !
Alan ,
Nope ,taint that (money thing) either . It is really so simple it may be hard NOT to look for a nefarious aspect. Don't fret over it too much . I can understand how a person living where taxes are so high may think it is a "money" thing. There is no money made ,by the government at least from licensing the primary users.There is a very SMALL fee paid for the permit around $20 to cover paperwork costs not a profit thing . Amateur radio operators here pay no fees for their license . I doubt the industrial users are a big enough market for the manufacturers to be concerned either.The interference ,on the RARE occasions it comes up are very easy to work with . We just discontinue local use on that freq. Again it is SO RARE it is a near moot point . Even the Nitro is low cost here . And with nearly 100 channels available to us for FREE ,we have little to worry about here .
It seems people over there would be all too happy to worry for us IF it were a problem. It is funny since it has no affect whatsover on them or the few frequencies they use. I don't even worry that NITRO costs so much over there. It's mere mention brings out the same sour grapes as the crystal non-issue.
100 channels FOR FREE ,huge plentiful flying fields , low cost supplies , cheap nitro and no huge MOT taxes on the lorrie for transport . It ain't no money thing yet . I ain't kicking

YUP we sure nuff figgered it ouwt. Cheerio

PS most of the "interference" is in very heavily populated areas . I think Cook county Illinois (Chicago area) has over 1000 LICENSED, primary users . They run such trivial things as cranes and other industrial equipment.The system works FINE ,thanks. At the present many of the freqs on the RC bands are phased out since many industrial users are moving up to 460 -800 1200 Mhz freqs. So in time the rules may be relaxed a bit. Maybe by then synthesized RC gear will become the norm anyhow .
Either way we have it REAL GOOD [8D]

strato911

Yes it is... Some industrial users pay hundreds of dollars (yearly) for the right to use their frequencies.

I don't know what determines the price, but I assume it is location / bandwidth specific. In other words, if an industrial user wants a frequency in a town where there aren't many others, the price is probably lower then in a city with hundreds of industrial users.

The main point though is, the LAW says we can't swap crystals. That's why I purchased synthesized equipment.

Sport_Pilot

If they are interfering you can turn them in to the FCC. Not sure of the Primary and Secondary thing but that doesn't give them the right to step all over our frequencies. IMO about time the AMA asks for those frequencies between our channels. Voice pagers are not commen anymore, and the industrial cranes, etc. are moving into higher frequencies. That or ask for some of those Gegahertz frequencies for ourselves.

BTW keeping our transmitters between 5 KHz is no big thing. Doing that when swapping crystals shouldn't be that hard to do. Aparently Multiplex has figured out how to do this. But Futaba and Hitec want to sell their modules.

Sport_Pilot

There is a radio controlled crane at work, paid once, when we bought the crane. As far as I know their is no license fees on the 75Mhz band, no matter the use.

Sport_Pilot

Thought primary and secondary were when two users use the same exact frequency, not adjacent frequencies. I don't think we were secondary users on any frequencies except the 27Mhz band where CB is still the primary user, or at least I think they are still using them.

David Cutler

You could always look in the newspaper and see if there have been any major accidents involving heavy earth moving equipment.

The 72 Meg bands are also used (between our channels) by such machines, and the multi-million companies who pay a fortune for those frequencies could make it very difficult for us if they needed to. This is quite apart from the danger involved in interfering with such machines.

Only as a suggestion, let's make the assumption, this time, that the law is there for a reason, eh?

-David C.

Sport_Pilot

R/C heavy earth moving machines on 72 Mhz?

Find any radio control systems that are near our frequencies on this site of a commen industrial radio control manufacture?

http://www.bwieagle.com/remote_controls.htm

I didn't think so.

Whyes

Thinking it is so does not make it so .
Primary and secondary refers to PRIORITY regardless of frequency. It is basically that an unlicensed user must cease operation if he is interfering with ANY licensed operation .It also establishes that an unlicensed user must accept interference from licensed users who are operating within the law even on different frequencies from the ulicensed operation. IE a local ham coming in on your telephone while he is operating properly otherwise.
Having taken steps to license an operation and certify KNOWLEDGE of operation and technical standards gives you an up on those unlicensed hobby type operations.
The high fees discussed above may prevail in Canada but the fees in the US are very low for industrial RC licenses. The equipment is low power and range is limited.
It IS NOT primarily ABOUT TUNING . While tuning is important ( NO the NEW "modern" radios are NOT much different than 20 years ago ) It is about actually getting on the wrong frequency or modified radios operating at higher than allowable power levels . Todays radios ose the same crystal tolerance and virtually the same RF decks as 20 plus years ago . The "narrow" bandwidth being a function of the modulation or deviation level .
Easy rules to follow in any event . Just real hard for some people to understand . Get over the mystery ,follow the rules and have clean ,safe(r) fun.[8D]

BTW YES some EARTHMOVER ,heavy equipment functions are indeed radio controlled . The list mentioned is not all inclusive. As I said before industrial users are moving away from the 70 MHz freqs but the usage there is still quite active and DIVERSE .