Kevin Greene

My Feedback: (85)

[quote]ORIGINAL: AMA-69405


JR Tx modules, as well as JR non-modular transmitters, are tuned to the specific frequency of the installed crystal... they are not "center tuned".

Gary,

Then please explain this to me....I returned a module to Horizon as they sent me one on 35MHz instead of 72MHz...I asked for a replacement. The one that they sent me specifically stated on the receipt as be CENTER TUNED. And please tell me what frequency all of the other replacement modules that I have ordered as spares are tuned to as they came with no crystals!!!!

Kevin

AMA-69405

My Feedback: (22)

Kevin,

With all due respect, what you're saying doesn't pass the logic test:

- Why would JR (or any mfg, for that matter) go to all the trouble to make transmitters with removable RF modules, facilitating user-level frequency changes that maintain tuning integrity, and then ship RF modules with no crystal?

- Why, in both the XP8103 and PCM10X user manuals, would it state... "If you want to change a frequency, you can simply change the radio frequency RF module, commonly referred to as either an RF module or transmitter module"? If Horizon's intent were to allow frequency changes at the user level by changing only the Tx crystal, why wouldn't they just say "...change the crystal"?

- Why, in an RCU thread (JR Radios - Ask Danny at JR), entitled "8103 tx module crys. change", would a JR Product Support Technical Manager make this statement?

http://www.rcuniverse.com/forum/m_11...tm.htm#1144952

I don't know who you were dealing with at Horizon when you got these crystal-less RF modules, but something is very, very wrong... or there has been a recent 180 degree turn made with respect to Tx tuning philosophies at Horizon.

As an aside, it would be interesting to know what Horizon would have been doing with a 35 MHz module in the first place. They would have no legitimate reason to have one in stock, since 35 MHz is not legal for RC use in the US... air, surface, or otherwise. Are you sure it wasn't 75 MHz?

Gary L.

the troll

What is really confusing is that JR offers crystal sets...Tx and RX. Someone please explain that!

the troll

I bought a set awhile back and have noticed helicopters and men in black siuits everywhere now...is there any connection?

AMA-69405

My Feedback: (22)

It has been proven time and time again... there is no connection between helicopters and men in black suits.

FHHuber

The FCC says its LEGAL to change the RX crystal.. the RX sn't sending out RF that's going to create an interference problem to someone else. So if it isn;t tuned correctly... you end up with just the model's control being at risk... and the FCC isn't concerned with if you crash your model due to loss of control due to your own equipment having a problem. Just TX crystal swapping is illegal. You can swap RX crystals legally all you want and do any stupid swap you want, even though the stupid ones won't work... (like sticking a Hitech crystal in a Futaba RX... the frequency multipliers are different so you end up somewhere way the eck off frequency.)

**********
Note... there is stuff comming in via E-Bay that is not legal in the US. Hobby Services (Futaba service center for USA) Horizon (JR service rep) and Radio South (best all around out f warrantee service you can get...) have been refusing service on some top end radios because they are not FCC certified. If you buy a radio from e-bay... you may have simply wasted your money.

FHHuber

Seeearlier post... its been answered.

It is legal to sell the crystal... so you can take the radio in to an appropriate technician and have the radio retuned to the replacemnet crystal.

Its legal to sell the "Anarchists cookbook" Doing what is described (in detail) in that book will put you in prison for a LONG time.

There is no law against owning a crystal for every frequency. You can even get the 35 mHz european crystals... but its illegal for you to stick it in the TX if you are not properly able to do the test and tune the radio within FCC specification.

abel_pranger

FH-
Not according to AMA. According to their misrepresentation of FCC rules, you have to return the radio to the manufacturer (see post 1 in this thread).
Are we obliged to follow FCC rules as published by FCC, or AMA's presumptuous revision of them?

Abe

FHHuber

The manufacturer's rep is the ultimate in proper service... and your radio comes with info on getting it to the factory service center.

Its not the AMA's business to promote any particular radios service center... and they KNOW the factory rep can do the job right. Where is it wrong for the to say send it to the factory service center?

If you happen to know of a different place that has the right certification and you send it there.... no one is going to complain about it.

abel_pranger

That's what I've been saying all along, FH. I know of many people with the requisite 'certification' (according to FCC, though not according to AMA), and among them are the people that service my radios. As for factory service centers, nobody is saying it's wrong to send them there for service, but AMA says (or taken in the context, as a minimum infers) that FCC says the manufacturer is theonly facility where it can be done legally. Being such a law'n order kind of guy, it's curious that you choose to reinterpret this part of the rules rather than follow them to the letter in entirety and as promulgated by AMA, as you would apparently have everybody else do.

Abel

FHHuber

Again... look WHERE in the AMA documents the crystal swap INFORMATION is given.

Its not in the safety code... its in the formation about FCC compliance. If you meet FCC compliance... NO ONE will argue about it. since the AMA stated...send t to the manufacturer... they pointed you in the guaranteed direction of compliance, since not all "Joes TV" rapair centers have a clue about dealing with an RC transmitter. (and probably won't have the equipment to tune it...)

Its also quite likely for someone to want to change frequencies when the TX is still under warrantee. To not risk voiding the warrantee... send it to the manufacturer's repair center for the change and retuning service.

The AMA says... OBEY THE LAW. They didn't write the law. They didn't give any advice that will lead someone to disobey the law...

If the AMA didn't recognize that Radio South and other R/C equipment repair centers, other than the original factory reps, were OK to use... they wouln't have any of thier ads for radio retuning sevices in Model Aviation.

the troll

That is plain ludicrous. Get a cup of coffee and wake up man! Do you read your own posts?

So I guess if there is an ad in MA it is an endorsement...You are full of............. yourself

FHHuber

That's about stupid. (expected from the troll..)

There is a big difference in rectgnzing if a service is legal, then acccepting an ad... vs endorsing a company providing a service.

J_R

FH

Your personal interpretation of the AMA's current stand is apparently based on the statements made in the AMA 2003 or 2004 Membership Manual, including but not limited to the following:

"Frequencies for Radio Control:
1.0. The Federal Communications Commission (FCC) allocates
and manages radio signals and emissions in the United States,
including those used for radio control (RC) of models. The
transmitters and receivers used for RC must be manufactured to FCC
specified technical requirements and operated on specific
radio frequencies and bands. More complete information is
available in the Code of Federal Regulations (CFR),
reference 1. This document lists the current radio bands
designated for remote control of models."

If you chase down that reference, you will find that that is NOT the statement contained in the CFR's at those markers. Instead, they contain information from 2002 that has no reference to the statements in the Membership Manual. Care to explain that? The information in the Membership Manual would appear to be out of date, as you have been informed, more than once. It is interesting that you let your own interpretations of things influence your posts without any apparent basis for them. Another item of interest is your statement, in at least two separate posts, that changing crystals is a felony. If you chase down the facts by reading part 95 and then following the sources, you will find that the penalties are set forth in the Communications Act of 1934, which, of course has had a few amendments along the way. The fact is that violation is a misdemeanor, NOT a felony. Do you know the difference? As a matter of fact the following amendment makes it quite clear that even a second violation is to be treated as a misdemeanor.

"1954 - Act Mar. 23, 1954, provided that any offense punishable hereunder, except a second or subsequent offense, should constitute a misdemeanor rather than a felony, as those terms are defined in section 1 of Title 18, Crimes and Criminal Procedure."

The point here is not the issue of whether switching frequencies, in any manner, is safe or not, but that you are misinforming the members of this forum. Since you purport to represent the AMA position, it would behoove you to determine what the facts are and report them correctly, or label them as opinion.

FHHuber

So you want me to tell them specificly first time its not a felony... second time they get caught its "Leavenworth or bust." OK That's fine.

the troll

outa the pan into the fire... too easy I think I will pass...for now.

J_R

It might help if you recognize that the basis of your arguements in this thread are based on incorrect information in the Membership Manual. Information that may very well make all of your arguements based on that information incorrect and/or misinformation.

It is not even clear, at this point, that crystal swapping is a misdemenor, much less a felony.

The AMA has two frequency committees and a technical director. Why not call and find out what is going on? Is it possible that whoever approved the wording of the Membership Manual did not have the technical expertise to make the decision to print it? If you want to represent the AMA position, at least find out what the position is.

abel_pranger

Then where's the beef? If one obeys the law according to FCC, no problem.
According to FCC rules (as written by FCC) a crystal swap can be done by someone certified to have the necessary technical skills. Since they no longer issue the First Class RT Operator's License, the only individuals formerly 'certified' to do it are no longer. To date they have defined who is 'certified' only to the extent of what is not required, i.e., a Commercial radio operator's license from FCC. That leaves the matter of deciding who is qualified to work on radios in the R/C service up to the good judgment of the persons that operates them. I don't have a problem with that. Other rules in Part 95 say that the operator of the equipment is responsible for ensuring that it is properly maintained and so meets the emission standards set by FCC. This is really the bottom line objective, and if you will the essential section of the Part 95 rules. If you don't meet the emission standards you are in violation of the rules. No need for FCC (or AMA) to dictate how you ensure that you are in compliance with that rule regarding the emissions of your Tx.
It's clear from your posts that you are not qualified to swap crystals in your transmitters, so you are exercising good judgment by not doing it. I'm sure the same is true for many other R/C modelers. For those that can't do it and be reasonably assured that the radio will still be compliant with the FCC rules, it's obviously in their best interest to find someone technically competent to their satisfaction to do it for them. For those that can do it with confidence that it has been done properly, I don't see anything in the the FCC rules that prohibits doing so. The AMA rules are still problematic though. They say obey the FCC rules but then then state said rules as what they want them to be, rather than what FCC has actually promulgated. Sure glad I have a nice umbrella policy that is outside the domain of AMA's interpretation.

Abe

J_R

Hi Abe

I do think Mr_Matt had a very good point. Switching frequencies, with or without a module has to be done very carefully. I have seen owners of the new Spectra modules turn on, only to realize the radio was on the wrong plane selection, and thus wrong frequency, on more than one occassion. Changing modules, (or crystals for that matter), present the same need for total concentration of the user in making the exchange. It is all too possible to get the wrong frequency pin, or display the wrong frequency on the Tx, or simply to lose track of what you have done. There is a large opportunity for errors to be made, in each case, whether the exchange is made legally, or illegally. How many clubs have rules that even require the display of a frequency on the Tx? Ever since the change of displays from flags to showing the actual number on the Tx, more and more pilots have resisted displaying the information at all.

The legality of the situation is minor compared to the need for awareness/education by pilots making these changes.

I have questions in my own mind as to whether modern production techniques make this a technical issue at all. The issue of the user knowing and being aware of what he has done overshadows the actual act of changing frequencies by several orders of magnitude, in my view. It appears that we have several actual experts posting in this thread that might shed light on the technical issues.

wings

Ya, it that is the fact, then state the facts. Don't conveniently leave key peices of info out in order to strengthen your argument. But then it would be as fun would it?[X(]



Wings

FHHuber

so in your esteemed opinion.... because in some state DUI first offensce is a misdemeaner... and maybe even up to 3rd would not be a felony... we should all get blazing drunk and go driving?

the troll

Now Fred

You know That wings really means that the policeman shouldn't tell you that you will go to the federal pen for ten to twenty for Jay walking... Man you get outta shape. too easy... maybe you are a little tail heavy[X(]or maybe just too much throw....[>:]

wings

Nope, I think drinking a driving is stupid and careless. But that is not my point. My point is that you made a comment that was not true. Thats all

Let me give you another example. You could easily say you will loose your drivers liscense if you get caught speeding. That is true, after several offenses. But it would be misleading to say that you will loose your drivers liscense for speeding without telling the rest of the info.


Don't conveniently leave key peices of info out in order to strengthen your argument. But then it would be as fun would it? [:@]

FHHuber

Well... it is my opinion that changing your own crystal is stupid... in addition to being illegal. (still waiting for the FCC reply to confirm its illegal, but I have no doubt they will confirm it.)

Jim Finn

My Feedback: (2)

[quote]ORIGINAL: Ed N



"Any user modification of a Transmitter that might affect the
transmitted signal is prohibited by law and safety concerns. ................................. ( BY LAW! Not AMA but by national LAW!) is this right?