Re: cleaning
I am seeing a picture in my mind of a kitchen with motorcycle parts all over. Smells strongly of gasoline and kerosene. I don't remember where this comes from. Some low life I once had as friends
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Richard Knoppow
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#30303
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Re: SX-117 noise limiter behavior
It IS periodic, not random. Each noise pulse has a definite signature. It is well above average random noise. A noise blanker of any sort desensitizes the signal channel during the noise pulse. In
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Richard Knoppow
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#30302
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Re: cleaning
Tom, Kinda like rebuilding a carburetor on the kitchen table! LOL
Bob W4JFA
[email protected]> wrote:
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Bob
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#30301
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Re: SX-117 noise limiter behavior
Rich ¨C Ignition noise is far from periodic. It may approach that at a constant speed, and may be somewhat predictable in the same vehicle where the receiver is. An SX117 for example and most others
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Mike Feher
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#30300
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Re: SX-117 noise limiter behavior
True, but a good approximation of the noise in the vicinity of the receiver antenna can be sampled and used to reduce the noise coming in along with the desired signal from the main antenna. The
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Mike Langner
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#30299
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Re: SX-117 noise limiter behavior
Well, you are speaking of _random_ noise, like natural radio noise but blankers are intended to work on periodic signals such as ignition noise.
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC
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Richard Knoppow
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#30298
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Re: SX-117 noise limiter behavior
I believe the Collins used this technique for the NB on the 75S and 51S receivers. Should really look. It has the advantage of a very wide band input. For ignition and other pulse noise the NB
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Richard Knoppow
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#30297
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Re: cleaning
And I wonder how many of them, *if married*, are no longer with us ??? hahahahaha
Tom Latimer
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Thomas Latimer
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#30296
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Re: SX-117 noise limiter behavior
It seems to me, that since noise is neither correlate-able or stochastic, elimination is not possible. Also the multiple antenna theory is out the window since RF generated noise travels at the speed
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Mike Feher
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#30295
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Re: SX-117 noise limiter behavior
Another technique for reducing or eliminating noise was to introduce local noise to the front end of a receiver from a local "noise antenna." The amplitude and phase of that noise could be adjusted
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Maynard Wright, P. E., W6PAP
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#30294
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Re: cleaning
There are some, who put entire chassis in the dishwasher as long as components like transformers and/or coils are removed.
From our file department.
*K2WH
Bill's QRZ Biography (
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Bill (Group Owner)
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#30293
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Edited
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Re: SX-117 noise limiter behavior
Can't read the whole book:-) Look at any of the classical receivers, say a Hallicrafters S-40. That has a series diode noise limiter. I think the S-20R has a shunt limiter. Series limiters began to
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Richard Knoppow
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#30292
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Re: SX-117 noise limiter behavior
Back to noise? stuff only
Richard you say halli used a ?Noise ?LIMMITER ?, not a blanker? but it is an ¡°unusual noise limiter arrangement¡±
Is there a standard arrangement? And what is it?
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don Root
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#30291
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Edited
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cleaning
I didn't believe it, till I used it, but for cleaning radios... chassis and all - "Scrubbing Bubbles"? works swell.
TriFlo teflon lube is good for breaking loose Pot and Variable Cap shafts... a
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Tom Dailey
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#30290
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Re: SX-117 noise limiter behavior
Well, that's useful to know. Actually, I have some Kroil, my local hardware store just began to stock it along with gun cleaning stuff.
I agree that recommendations for cleaning based on
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Richard Knoppow
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#30289
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SX series S meter
Anyone have an SX series S meter they wish to part with? SX99 I am working with needs one replaced. Plastic face is broken and cracked badly.
thanks
keith
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Keith
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#30288
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Re: SX-117 noise limiter behavior
RichardI am recommending penetrating oil to clean and lube switches and pots.? Kroil, Deoxit and the like are effective but are also expensive.? Just trying to point out that there are alternatives
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Jim Whartenby
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#30287
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Re: SX-117 noise limiter behavior
The noise limiter in the SX117 is somewhat unusual. It is a diode noise clipper, similar to the conventional limiters found in many receivers, but works at IF frequency rather than audio. It is NOT
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Richard Knoppow
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#30286
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Re: SX-117 noise limiter behavior
FloydYou originally said: "Haven't dug into this yet, but wonder what other SX-117 users see when turning on the Noise Limiter in? USB or LSB mode.? On my receiver, it's like disconnecting the
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Jim Whartenby
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#30285
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Re: SX-117 noise limiter behavior
A noise limiter (usually a diode or two) clips off audio above the strength that the desired audio wave reaches. Some observers say it should be called a clipper, not a limiter. Often the
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Mike Langner
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#30284
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