| Eric Henderson send me this marketing data from JR. I guess he likes
to see me type. Anyway - I'll attempt to input it without too many
typos.
Bye --+--
Kay R. Fisher |
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WE DO WINDOWS
Automatic Blocking Circuit With Window. ABC&W
With 1991 just around the corner, everyone's attention is focused on
receivers meeting the new AMA guidelines for narrower channel spacing.
JR and Hobby Dynamics Distributors have taken the initiative to have all
JR receivers tested in independent labs. As expected, JR's 1991 narrow-
band performance was certified, all AMA guidelines were passed, and their
receivers are included in the AMA RC Equipment Certified List.
Even more impressive is the fact that JR has accomplished this with the
use of single conversion. Back in 1986, JR designed a revolutionary
electronic circuit called ABC&W (Automatic Blocking Circuit with Window).
Traditional single conversion uses one IF section to filter out signal
noise. Similarly, dual conversion receivers have two IF sections, the
second filtering what the first missed. ABC&W uses a very small electronic
window, and any signal that is distorted or off-frequency and won't fit
through is immediately grounded. Then, the new signal is cleaned up,
amplified, and sent through the window again. And again. And Again. Until
all that is left is the pure signal coming from your transmitter.
ABC&W offers several advantages over the other two systems. Unlike other
single conversion receivers, JR's have passed all AMA guidelines for 1991,
including 21M and 3OIP. In Orlando, Florida, the AMA Frequency Committee
subjected JR receivers to a series of 21M and 3OIP tests in today's environment.
The result? JR passed them all with flying colors. And while dual conversion
receivers may meet the same standards, their design makes them considerably
larger larger and heavier and mores costly. At this point, you may be wondering
why everyone isn't using ABC&W technology. The reason is because it's patented
by JR, and you'll only find it in JR receivers.
So don't let anyone tell you dual conversion is the only way to go.
Understand the facts, and choose the system that will perform the best for
your needs. If you own an older JR radio, sent it to JRSA for a narrow-band
upgrade. And if you have any questions we haven't covered, please call one
of our JRSA technicians at 1-217-355-9511 (8 am - 5 pm CST).
"JR ABC&W single conversion receivers are 100% bullet proof!"
- George Steiner, Frequency Advisory Committee
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Questions and Answers About "1991"
It was great to see so many of you at the Chicago RCHTA show this past October.
A variety of questions were asked about the upcoming "1991" change. This
Question and Answer section has been compiled to clear up any concerns you
may have about "1991".
Q: Which radios are "1991" approved?
A: Production of "1991" approved JR radios began in October, 1986.
All JR radios produced since then meet and exceed the "1991" standards.
Q: Is there a way to identify a JR "1991" receiver?
A: Yes. "ABC&W" is printed on the label and the crystals are gray. If you
are unsure, call JRSA (217)355-9511.
Q: How can I tell if a JR radio is "1991" approved?
A: All "1991" approved JR radios have the ABC&W trademark printed on the
receiver. Our Narrow Band Upgrade Program was designed to convert older
radios into "1991" approved systems.
Q: How does ABC&W (Automatic Blocking Circuit with Window) make a JR radio
narrow band?
A: JR's patented ABC&W circuitry makes all JR systems the most signal selective
radios on the market. ABC&W is an electronic windowing circuit which
basically eliminates the need for dual conversion. The circuit is very narrow
and will only let narrow electrical signals through. Anything that doesn't
fit through the window will be blocked out and disregarded. In addition to
the ABC&W system, JR has exceeded the industry standard signal selectivity.
While the rest of the manufactures have receivers with signal selectivity at
20 KHz, JR has achieved 10 KHz spacing with the ABC&W system. This means
JR has more than doubled the strict regulations for "1991".
Q: What are the new channels and when will they be available?
A: Both even and odd channel JR radios will be available beginning January 1,
1991.
Q: Who should I contact if I have questions?
A: Contact a Customer Service representative at JRSA (217)355-9511.
================================================================================
1991 NARROW BAND RADIO SYSTEMS UPGRADE PROGRAM
JR Service Americas is offering a special radio system upgrade program to owners
of JR radios. This upgrade program is designed to help make the transition into
"1991" as easy as possible.
If you JR radio system came with an ABC&W receiver, no upgrade or modification
is necessary to fly right into 1991! If you happen to be the owner of an older
JR radio system such as an Apollo or Unlimited 8 or purchased a Century 7,
Century 7 PCM, or PCM-9 system before October 1986, you will need to upgrade
that system in order to fly after January 1, 1991. For complete information
you can call us at JR Service Americas, (217)355-9511.
================================================================================
I'm only the messenger. I don't owner JR radios at this time.
Bye --+--
Kay R. Fisher |
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|
| What are you worried about Kay??????? Not the fact that JR makes a
hell of a radio I hope!!!!!!
Although I can't give everyone all the details, there are people who
know what I'm going to say and I'm sure will fill in the gaps.
After reading your entry, I'm sure there will be many who will continue
to say "it's just hype". Well, there was a contest recently out in
the warmer climbs where virtually everyone had interference problems.
The interference was caused by some local something or other. When I
say everyone, I mean everyone EXCEPT JR owners. Nary a one had a
problem. People want proof and not manufacturer hype. I think this
contest is it.
Now, will someone who knows all the particulars please fill in the
blanks!!!!!!
Steve
|
| >> there will be many who will continue to say "it's just hype".
And I clearly am one such. Let me defend my use of the word, "hype".
First, no single contest can prove immunity. It might be data, but it
isn't proof. Otherwise one could cite a zillion contests to prove that
"channel 20 cannot shoot down a channel 56 receiver", but we know that
there are circumstances where 20 can indeed shoot down 56. Likewise
the Orlando test was a test, not a proof. I accept it as data.
As for the marketing material entered by Kay, the first part through
the description of dual conversion receivers is OK, it's not hype.
The rest of the first part (through the phone number) is a mixture that
is almost acceptable as a reasonable simplification. It has statements
I agree with (that you can have narrow band without dual conversion)
and statements that are nonsense ("any signal that is distorted ...
is immediately grounded" and "Until all that is left is the pure signal
coming from your transmitter"). If this last statement were true, the
military would pay a fortune to use the technology. That's hype.
Reconstitution of digital signals does give a sort of "purity", but
noise or interference can result in this purity being erroneous.
Moreover, the reconstitution is at the video stage, and RC
interference contributes its damage in the earlier stages.
>> While the rest of the manufactures have receivers with signal selectivity at
>> 20 KHz, JR has achieved 10 KHz spacing with the ABC&W system.
This statement is misleading. The first phrase associates the 20 KHz
number (whatever that means) with all other manufacturers. The second
phrase is a simple statement of likely fact. The combination implies
that somehow JR is better, perhaps by a factor of two in some dimension.
Signal selectivity at a particular frequency is a parameter, not
something I have or do not have. It has a value that can be measured
for any radio, including JR's. I have the laboratory test report on
the Airtronics 92765 receiver, and the adjacent channel rejection is
-81.3 dB at +8.5 kHz and -69.2 dB at -8.5 kHz. --- An adjacent RC
channel would have to have a power density at the receiver about 10
million times that of the proper channel in order to attain equality at
the IF output. Unless this filter has significant sidelobes [unlikely],
the selectivity at 20 kHz off nominal would be very severe. In comparison,
the JR manual gives the NER-627XZ receiver selectivity as "8 KHZ/50 dB".
In this context, "50" isn't nearly as good as "69", although it is
possible that the "50" number is a loose spec not representative of a
better reality. The Airtronics numbers appear in their brochures, so
JR had access to them and had no justification in implying that the
Airtronics receivers are deficient.
The first phrase could mean that all other manufacturers offer for sale
at least one non-AMA-listed receiver. That might be true. But in this
interpretation it says nothing about the listed receivers.
Depending upon interpretation, the first phrase is either useless, false,
or a tautology. That sentence is hype.
|
| What kind of "proof" are you looking for Al. I'm beginning to think
that, short of a full blown break down of the circuitry, there's
nothing you'll except You keep quoting Airtronics data and who's to
say THAT isn't hype. It's very easy sometimes to present "data" so that
it's in your favor. I'm not bashing Airtronics here either. I have two
Airtronics radio's and an extra Airtronics flight pack.
People say they want proof, not numbers. They want to see the
inteference, or lack of it, in action. I wish I had all the details
concerning this contest, but it would seem to me that if both Futaba
and Airtronics radio's on many different channels were getting hit to
one extent or another, and JR came through realitively unscathed, that
to me is a fair amount of proof.
I also think your misinterpreting the JR explanation of how it works.
I could be wrong here too, but I don't believe that if the receiver
detects a bad signal, that it goes into an infinate loop trying to
clean up the signal. It may try for say .3 tenths of a second and then
if it still isn't acceptable, it throws it out and sees if there is
another good signal. So I don't except your explanation of why JR'S
explanation of how it traps interference is hype.
Steve
|
| Can someone please give me some information on the JR X-347? I would like
to know especially about the glider package. What number and type of servos
(technical data, please) is included and what are current market prices
in the US?
Thanks in advance, and best regards,
Hartmut
|