[SPAM] Re: JR 10SX
Bill Glaze
billglaze at triad.rr.com
Tue Mar 22 12:17:04 AKST 2005
Ed: It is definitely more unnerving to be able to see a huge source of
RF, than to not see it. If these antenna sources of which you and I
speak were not such high visibility items, probably nothing would be
thought about them. As far as the NavAid goes, it is probably on 108 to
112 MHz, I wonder if they're using that for a primary? If they're
doubling, it could create some problems, I guess. But, OTOH, they're
primary, so I guess they can generate just about however they want,
(within what the FCC approves,of course.)
BTW: Next time we get together, ask me about the time I was flying, and
the city of LAX decided to try out their new traffic transmitter on
27.255. We eventually found the airplane uninjured. Now THAT'S luck!
Bill Glaze
Ed Alt wrote:
> Bill:
> That's true, we basically are stuck with accepting interference from
> outside sources.
>
> BTW, you should see the field that Joe L. flies at - you stand with a
> VOR NAVAID 150 feet behind your back. No problems so far, I've flown
> there twice now. Granted, it's around 40 mHz off, but it sure is
> nearby physically.
>
> Ed
>
>> From: Bill Glaze <billglaze at triad.rr.com>
>> Reply-To: discussion at nsrca.org
>> To: discussion at nsrca.org
>> Subject: Re: [SPAM] Re: JR 10SX
>> Date: Tue, 22 Mar 2005 09:27:04 -0500
>>
>> Ed:
>> Do you not think that we will always be subject to interference as
>> long as we are "secondary" users? Admittedly, more could be done. As
>> an aside: I fly frequently at a field that has a huge (2000 ft. tall)
>> antenna directly behind us. It is no more than 300 yds. away at the
>> flyers 6 o'clock position. Yet, even though pattern flyers won't
>> come and fly there, (probably because of the frightening specter of
>> that powerful antenna) folks fly there literally every day of the
>> year with no interference. I'm one of the frequent flyers.
>> Unfortunately, it seems that most of the pattern folks have just
>> enough information to be dangerous when they shun this field.. BTW:
>> a check for interference shows that there is less interference
>> literally in the shadow of this antenna, than there is at another
>> local field, yet the other field, which shows a higher level of
>> "hash" is quite popular. Ignorance is bliss.
>>
>> Bill Glaze
>>
>> Ed Alt wrote:
>>
>>> John:
>>> I think that they used to call that Kraft with the syntesised RF
>>> module "dial-a-crash". Actually, the technology for synthesising 50
>>> channels is no big deal, PLL circuits have been used to do this for
>>> decades. Back in the early 80's I did my senior year electronics
>>> project by taking an Ace Silver 7 receiver, disabled the local
>>> oscillator and injected the output of a PLL local oscillator of my
>>> own. It was just a bench prototype for a grade, clunky to look at
>>> and with 7 seg LED readouts to display the channel it was on, but it
>>> worked. I got alot of curious looks from the class when I hauled in
>>> a Kraft single stick, a Heathkit GD-19 and a Futaba FG series radio
>>> on different channels to demonstrate that it worked to the Prof.
>>> Nowadays, this stuff can done in software with DSP technology. I
>>> can see the wheels turning in your head already! :)
>>> Spread Spectrum would be one way to go, or maybe something using
>>> WiMax technology, whenever that shakes out. Eric is right, our
>>> technology for the RF link is totally archaic. Nice that we have
>>> good, reliable "narrow band" stuff now, but it could be much better.
>>> Ed
>>> ----- Original Message -----
>>>
>>> From: John Pavlick <mailto:jpavlick at idseng.com>
>>> To: discussion at nsrca.org <mailto:discussion at nsrca.org>
>>> Sent: Tuesday, March 22, 2005 1:10 AM
>>> Subject: RE: JR 10SX
>>>
>>> Yeah, I agree with Eric. As far as I'm concerned, the new Futaba
>>> radio (14MZ) is really nice looking, and of course I wouldn't mind
>>> having one BUT since I don't fly the really big stuff where 14
>>> channels is a big help (multiple servos on each control surface),
>>> it wouldn't be much of an improvement over my 9ZAP. It seems like
>>> the RF section is always an after-thought. I remember when all the
>>> "new" frequencies were being discussed (pre 1991 times). One of
>>> the ideas behind getting all the new frequencies was to reduce the
>>> chance of someone being on your frequency. I always thought a
>>> better approach would have been to make everything with
>>> synthesized RF decks. Since the plan we adopted ended up making a
>>> lot of otherwise good equipment obsolete anyway, I don't see what
>>> the problem would have been. We wouldn't need as many channels
>>> that way either (more room for other stuff). If you can select
>>> your frequency, rather than just increase the odds of not being on
>>> someone else's frequency, then the real problem is solved. I seem
>>> to recall that Kraft had synthesized RF and "narrow band" FM
>>> equipment before anyone else. Almost every major radio
>>> manufacturer has some type of synthesized RF deck today.
>>> If you add the synthesized RF deck to a digital encoding "code
>>> hopping" transmitter and receiver you have a good solution to our
>>> newest problem. As long as the receiver isn't swamped by a very
>>> high output transmitter, this is safer than what we have now. A
>>> code hopping system uses a digital encoding scheme in addition to
>>> the base frequency. The "digital key" changes when the system
>>> powers up. You don't even know it's happening. Even if someone is
>>> transmitting on the same frequency, if the "keys" don't match the
>>> receiver won't respond. That's over simplifying a bit but that's
>>> the basic idea. There's more to the link than just the RF
>>> frequency, which as we all know is not always exclusive. Clothes
>>> pins with channel numbers are not exactly a foolproof method of
>>> securing your frequency. This kind of stuff is in $40.00 cordless
>>> phones and garage door openers - remember the old garage door
>>> openers that used to open for "no reason"? How do you think they
>>> fixed that? Why can't this technology be used in a $2000.00 radio?
>>> If we keep building bigger and bigger airplanes and controlling
>>> them with what is basically outdated technology, it's only a
>>> matter of time...
>>>
>>> John Pavlick
>>> http://www.idseng.com <http://www.idseng.com/>
>>>
>>>
>>> -----Original Message-----
>>> From: discussion-request at nsrca.org
>>> [mailto:discussion-request at nsrca.org]On Behalf Of Grow Pattern
>>> Sent: Monday, March 21, 2005 11:48 PM
>>> To: discussion at nsrca.org
>>> Subject: Re: JR 10SX
>>>
>>> Bill, the update to the 10SX (actually a 10SXII) was the
>>> digital trim 10X. Is the 10X what you meant
>>> to say?
>>> In general terms I don't intend to buy another
>>> radio, of any
>>> brand, until they fix the weakness of our RF link to the
>>> plane. We can all still be radio-shot-down far too easily.
>>> Regards,
>>>
>>> Eric.
>>>
>>> ----- Original Message -----
>>> From: William C. Harden <mailto:flyinbill1 at bellsouth.net>
>>> To: discussion at nsrca.org <mailto:discussion at nsrca.org>
>>> Sent: Monday, March 21, 2005 9:42 PM
>>> Subject: JR 10SX
>>>
>>> Now that JR has come to market with their new 9303 radio,
>>> does JR intend to update their 10SX radio? If so, when
>>> will the new radio be available??? Just curious.
>>>
>>>
>>>
>>>
>>>
>>> Bill
>>>
>
>
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