slarty

Hmmm this is a bone of contention.... it is a 388S with the 8th channel disabled and relabelled !

Doc.316

What about the Apolo 4 (I believe)...it was the original $99 radio (and was amazing since it was only 99 bucks...).

Steve

luv2flyrc

My Feedback: (6)

Yep, I can date that one for you. I bought one when it launched in 1996.

Mike

Chad H

The first generation PCM10 was the PCM10Z. I have three. The origonal I have was purchased in summer/fall of 1989.

This radio was so many light years ahead of the competition it is not funny.

The majority of radios used today still can`t touch it.

Its major drawback is the low resolution, and can only use Z recievers in PCM mode.

And the delicate touch screen was its weekest point, that is why I bought two more, just for the screen. The screen is still available, but you have to send it to Horizon for them to mount it in. You really have to watch model fuel around it, and Windex is a death blow.

Hitec [:'(] has gone touch screen on their top of the line, big mistake (besides the fact its resolution sucks).

If it had higher resolution, I would invest in a 2.4 module for it, and still laugh at other club members sub standard new equipment they are using compared to what it does.

But I broke down, and just got a 11X, to again be years ahead of what other modelers have in it`s price range.

I have used that radio, and another JR TX since 1989, and have not had, ever, one glitch, malfunction, or problem of any kind.

JR radios to me is their RELIABILITY.

I will never trust my models to another brand.

Zor

I did not see the XP7202 in your list..

jaka

Hi!
I bought my first JR radio, 8 channel PCM/PPM 8 (Looked the same as what you call a "Unlimited series) in 1980 when the first JR radio came about.
Then a 7 channel "Core" in 1984-1989.
Then a 347 in 1992 and a 388X in 1994.

CPS

I am JR fan since 1980 and always love it.However,I nearly changed after into 2.4G .There were many unknown "Lock-Out" events happened.Maybe you said it is due to the battery but I didn't hear simular events occurred about "F" radio.If the JR didn't change its 2.4G modulation style soon,I thick "JR" will become 'history" quickly![&o]

chistech

There was the Circus IV and VI. The 6 was offered in both a helicopter and airplane version. I have the 6 in helicopter and the 4. I bought the Circus 4 with 4 servos and nicads for $99 direct from Circus in Nevada back in the early 80's. They were the best radios and for the price couldn't be beat. I later bought a Century VII and now own 4-7202's (2 new in box) and a 9303 with both the synthesized and 2.4 (new style) modules. Still love 72mhz.

Zor

chistech,

Many have radio favorites. The JR XP7202 is hard to beat considering its features and cost.

The DX7 is an identical radio but for modulating a 2.4 Ghz carrier instead of a 72 Mhz.

To my knowledge the modulation envelope is the same which puzzles me reading the following . . .

cps,

If the JR didn't change its 2.4G modulation style soon,I thick "JR" will become 'history" quickly!

I do not know that the modulation on 2.4 Ghz is any different.

The receivers simply demodulate the modulation envelope and feed the signal to the same servos.

Perhaps "modulation style" is referring to the carrier frequency shift .
While this may be different it seems to me that the important factor is that thereceiver can pick up the carrier and provide the servos with their instructions.

Am I missing something ?

Zor

CPS

I don't want to make another debate about the advantage & disadvantage of DSM2 and FHSS but many evidence proved it .In the JR and Spectrum forum ,many discussion related unknown cause of "lock-out" but more less in the "F " forum.Perhaps 90% is resulted from battery,however,I didn't hear any simular cause of "lock-out" about "F radio.I very like the looking of JR trasmitter and the easy program character,but I can't fully trusted its 2.4 G for my fast-speed jet like I trusted its PCM before! Therefore,I still use the PCM modulation for my new 11X instead of its 2.4G system.

Zor

Hello CPS and readers.

Red text that follows is inserted by Zor.
I believe CPS is responding to my previous posting.

Anxiously awaiting any reply and clarification.

Zor

fizzwater2

My Feedback: (61)

I believe in other parts of the world you can get a module based 11X so you can use 72Mhz, etc. still.

Zor

Hi fizzwater2,

I am inclined to agree with you and I think all recent transmitters are made of modules (interconnected P C Boards), one of which generates the radio frequency for differet radio bands.

I did quite a bit of research via the internet but little informaton was found.
You may see (have seen) the inside of a JR XP7202 pictures I recently posted.

The point I have made boils down to whether the signal is modulating a 2.4 Ghz or a 72 Mhz or 35, 40 Mhz. the modulation would be the same.

We cannot mix the modulation and the carrier as being the same thing.
One flier may prefer the 72 Mhz band (VHF) instead of the 2.4 Ghz band (UHF) with its frequency hopping (spread spectrum) but the modulation and the system features would be identical as far as controlling the model. An 11x is still an 11x whatever band it is operating on (operating in, if one prefers).

I have both a JR XP7202 and a Spektrum DX7 and they are the same radio with the same so called programming ( I prefer to refer to that as selecting pre-programmed software functions) . The 7202 is "synthesized" meaning it can operate on any of 46 frequencies and if the receiver is not locked to the selected prequency it will not respond. That is a similar feature to the binding and the "model match" of the 2.4 Ghz version.

I have a strong feeling that the range of the 72 Mhz band is much further than the 2.4 Ghz band. I hate to make unexplained statement so my reasons is that the acquired energy of a receiving antenna is somewhat proportional to its length exposed to the radiated field. Long waves below the AM broadcst band can go all around the world. VHF is limited to line of sight.

Our usage in general is limited to the size we can see our models to control it. So any range sufficient to do that is adequate. Note, passing by, the limitations in range for park fliers.

I can easily understand fellows pointing the antenna at the model and complaining about "brown out" on a 2.4 Ghz system. I think the operation on 2.4 is with much weaker signal strength than on 72 or lower frequencies.
I remember the days when semiconductors to operate above 30 Mhz did not exist.

Please excuse me for my interest in these general subjects. It is all part of this hobby for me.
I do not think of that while flying L O L.

Have great flights fellows.

Zor

Red B.

Here in Europe, and probably elsewhere, the 11X Zero can be had in a modular variant that allows the RF module to be exchanged between 35 MHz, 40 MHz and 2.4 GHz: [link=http://www.modelflying.co.uk/news/article.asp?a=5605]JR 11X Zero[/link]

Even better, presently JR is introducing its own (non-Spektrum) frequency hopping spread spectrum 2.4 GHz system, that also includes telemetry. JR calls its new modulation system DMSS, which is distinct from both DSM2 and DSMJ: [link=http://www.rotorworld.co.uk/index.php?option=com_content&view=article&id=733:introducing-xg7-the-first-100-pure-jr-24ghz-radio&catid=3:radios-a-electronics&Itemid=192]JR XG7 DMSS[/link]

CPS

If the DSM2 is good enough,why did the JR changed so many 2.4G modulation so quickly?(DSM>DSM2>DSMJ>DMSS)?Finally ,the JR went back to FHSS type 2.4G modulation as other radio .Thanks God!

Zor

Hello CPS,

I suspect very much that there is a trend to standardization in the UHF technology.

What is being changed is not the modulation.

I remember the days when computers could not communicate with other manufacturers computers; when servos were specific to their ownbrands; We still see some of this when connectors are not standard.

FHSS being a frequency hopping system, what is hopping is the radio carrier. The carrier is the high frequency fed to the antenna to radiate some energy. The modulation is the signal like PPM (FM), CPM, ZCPM, SCPM and other modulation methods that are carried by the high frequency carrier.

We must not confuse the two as being the same thing.

Whatever the hopping method used, the modulation of the carrier is what carries the command signals.eventually responded to by the servos.

As I said before, if we can use different brand servos with a JR system and the same different brand servos with Futaba, Airtronics, Spektrum, and others and whatever the radio frequency band is used, 40 Mhz, 72 Mhz or 2.4 Ghz. that modulation of any of these carriers whether they are in a fixed narrow channel or hopping into the 2.4 Ghz band (one of the ISM band, please see link below) it all ends up with a signal that the receiver can present to the servos for their part of the control system.

The following link has a lot of valuale information ____

http://www.answers.com/topic/ism-band

Many readers may gain some understanding at that site if interested.

Enjoy,

Zor

ira d

Zor your definition of modulation as to how it works is correct, However what CPS said about JR changing their radios IMO is also correct. Of course
no will know for sure untill it happens but I do think if JR wants to stay in the game they are going to have change to what the cust base feels more
comfortable with.

Lets say just for the sake of argumentthat 90% of the reportedSpektrum failures have been false which by the wayI dont think they were, JR will
still have to make some changes unless they can prove the failures were false because their cust base has become uneasy with their system.

CPS

I don't care the definition of "modulation.Just give me one reliable 2.4G transmission way.At present time,it seems to be the FHSS type of transmission way.If the DMSS is correct selection of JR,the time will tell us! I just hope it didn't spend much time.

Zor

Good morning ira d and all readers,

I am glad to read you ira d.
As you are aware, I think, I am always concerned with the readers (non participants in posting) and particularly the beginners who have some interest in knowing more about the technicalities of this fine hobby,

I have been trying to assure that there is no confusion about the communication link between transmitter , receivers and servos.

It should be clear that the carrier is the high frequency electric current in the transmitting antenna that by radiation induces in a receiving antenna a small amount of energy that the receiver uses to pass along to the servos the type of signal (command) that the servos are designed to work with.

It should also be clear that the modulation is a variation of the carrier; the modulating process of which there is many types.
AM (Amplitude Modulation) as is used in the AM broadcast band550 Khz to 1620 Khz. (some other frequency range in other parts of the world) in which the amplitude of the carrier is varied according to voice or music wave forms.

FM (Frequency Modulation) as is used in the FM band 88 Mhz to 108 Mhz in which the carrier strength is constant and the frequency of the carrier is shifted according to the voice or music wave form. The shift goes up to 75 Khz from the center frequency in broadcast but is limited to 6 Khz and even 3Khz in "narrow band FM" . Narrow band is used mainly in voice or in control systems. Itis also referred to as "FSK" (Freqeuncy Shift Keying).

PCM (Pulse Code Modulation) as is used in different form in the system we use to control our models. There is different forms (method) of modulating with codes. The codes are pulses of carrier frequency and is implemented in different ways by system manufacturers. The carrier come on and then disappear. CW transmissions is a form of "code modulation" according to the Morse character formation.

Pulses can vary in rate (pulses per second) or in duration (pulse width) and can be grouped to form "frames"..

In our usage, manufacturers have their preferences how to accomplish the commands. Some use an FSK (Frequency Shift Keying) on one side and others use the other side. Thus the receiver has to match (be compatible with) the transmitter. Some receivers have been designed to work regardless of the shif side either above or below the carrier center frequency.

In FH system (Frequency Hoppipng) in the 2.4 Ghz band there is different ways of controlling the hopping. In effct the receivers are hearing a wide part of the band but are looking for a specific digital sequence (a number if you like) that they have been told is for them (the binding process).and will disregard anything that is not that specific code.

Since only the transmitter they are bound to sends this code then the receiver disregards any other signal (other radiaton) . Radio frequency noise does not have this code.

Most systems these days use the width of the pulses (their duration in time) to determine where a servo should go and hold.

Voila for a long posting. Hoping the above is pretty clear.

Have a great day all,

Zor

The editing was only to correct multiple typing errors (spelling).

fizzwater2

My Feedback: (61)

gee, all the way from history of JR radios to yet another FHSS DSSS argument.

Zor

ira d,

Clarifying the situation ___

In post #61 I read "why did the JR changed so many 2.4 G modulaion so quickly"

As I wrote in post #66, FHSS is not a modulation.

If the modulation was changed then the servos would not know what to do.

Zor

Zor

Hi CPS,

Some do not care and some do.

To decide on a reliable 2.4G (Gigahertz) system it is very useful to understand the features of a system and hopefully when available the reasons behind the adoption of the methods used in the system.

Like anything else, manufacturers are groups of people having their opinions based on their own experience and experiments. Then comes the advertising industry claiming that their client has the best and you the buyer MUST buy this system.

Manufacturing competitors watch carefully what the others are doing. People in the engineering departments who design systems are in contact with each others under the table (if you understand what I mean).

It is all part of the modern (present times) ways of doing business and maximize the financial profits.

So CPS let us know if you are part of the radio control manufacturing industry and which system You think is best and why.

If your interest is simply to acquire a reliable system, let us know what your decison is and again why you made the decision.

This informatin (decision) may help us all.

Zor

Zor

I think not many participants have either interest or knowledge of JR's history. LOL.

The idea of the thread seemed to have been to list the JR models and post pictures.
It looks like that has been accomplished early in the thread to the extend that anyone knew.

Perhaps we coould read the latest results ???

Zor
The old motto "There is as many histories as there are historians".

CPS

I have given up the DSM2 or DSMJ.Wait for the DMSS!

Zor

What is DMSS ?

http://acronyms.thefreedictionary.com/DMSS

Trying to find out.

Zor