Today's Message Index:
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1. 11:53 AM - Re: Garmin 250XL Squelch Issue (Bitterlich, Mark G CIV NAVAIR, WD)
2. 03:46 PM - Re: Re: Garmin 250XL Squelch Issue (Robin Hou)
3. 08:59 PM - Anyone know of a A&P that can work on Yaks in Seattle? (AndyRutherford)
Message 1
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| Subject: | Re: Garmin 250XL Squelch Issue |
Ok, your description is making some assumptions about what is going on, which I'd
advise we not do. I'm still less than clear on EXACTLY what is happening,
although we are starting to zero in.
So ... are you saying that when the Icom equipped airplane is close to you, and
makes a rather long transmission ... something happens. Question: Do you stop
hearing him WHILE he is transmitting, in that he is talking, you hear him,
then WHILE HE IS TALKING, YOU STOP HEARING HIM? And then you can't hear ANYONE
else? Go through this with me again step by step. Or tell me I've got
it correct please.
The most important statement you made was that you could press the SQ switch initially
and things would work, and then pressing it again later on..... results
in nothing being heard on ANY freq.
Let's talk about that SQ button on your radio so you are clear what it actually
does. It does not "reset" ANYTHING. It simply turns Squelch OFF. With squelch
off, and the volume turned up, you should be able to hear static in your
headset. Try this on the ground with the engine not running, before your flight.
Just push the SQ once, listen for static, push it again and the static goes
away. So it is a SWITCH ... push once, it turns off squelch, push again it
turns it back on.
I think you are getting the wrong idea of what "Automatic Squelch" really is.
It is not something that is "adjusting itself" in flight. It is in fact nothing
more than a comparator circuit which measures signal to noise ratio, and when
the signal to noise ratio achieves a PRESET LEVEL, the speaker is turned on.
That is ALL that it does. Pushing the SQ switch just turns the speaker on
ALL THE TIME and bypasses this circuit. Pushing the SQ button does nothing
to "reset" or "readjust" anything. It just bypasses the circuit that turns your
speaker on automatically when there is a strong enough signal.
Now that you understand this, a light bulb should be starting to glow a little
bit.
The situation is simply this: You are close to an aircraft with a strong transmitter.
I don't believe it has anything to do with the other aircraft having
an Icom radio, OTHER THAN, it has been my experience that the Icom Radios put
out a tad more power than some others, and also they tend to modulate right at
100%, which is actually a good thing. But the point is that YOUR aircraft is
in the near field of this transmission, and that means your receiver is being
hit with a ton of energy. And ... I don't believe it is handling it too well
at all. Meaning, I think that there is a component in your receiver that is
being overloaded and then stops functioning. I base this on one very important
point:
You say that once it happens, you can push the SQ button one time, and you hear
no static, or transmissions from anyone else. We must be clear on the fact that
you now understand that the SQ button is a SWITCH. Hit it once, and it turns
the speaker on all the time, hit it again and it goes back to allowing the
circuit to turn on the speaker. You need to be very clear on this, and listen
to it on the ground with the engine not running, so you can fully understand
the function.
If you then go flying again consider pushing the SQ one time, and let it run with
the speaker on all the time. It is annoying I know, but do it. Then join
and tell the guy in lead with the Icom to transmit for 30 seconds or so. If
while he is talking, his signal just disappears and then you can't receive anything...
then my friend, your receiver has a problem, and should be returned for
service. And you will need to be very clear on the gripe: "When flying formation
with another aircraft and he transmits for 30 seconds or so, the receiver
stops receiving.... anything and everything.... and then works properly again
once it is turned off, cools down, and is turned on again." A tech will
immediately know how to test for that with a SigGen.
The above is true, only if I fully understand what you are telling me. If there
are further details, the above might be wrong! :-) I suspect that the first
RF amplifier in the receiver, or possibly the first mixer circuit is failing
to operate properly. But if I have all this right.... there is no question
that your receiver has an issue that needs to be fixed. (Sorry to tell you that).
Mark
-----Original Message-----
From: owner-yak-list-server@matronics.com <owner-yak-list-server@matronics.com>
On Behalf Of Robin Hou
Sent: Tuesday, August 07, 2018 3:29 PM
Subject: [Non-DoD Source] Yak-List: Re: Garmin 250XL Squelch Issue
Hi Mark,
Sorry, I should have been more clear. I say that the Icom would "trip my 250XL
squelch"; what I mean is when the Icom transmits, my 250XL auto squelch function
would adjust itself to a point that I can no longer hear any transmission from
any radio. It occurred mostly when the Icom equipped plane is flying lead
which requires transmissions lasting for a 30 seconds or so at a time. When the
Icom equipped plane is not lead and stays radio silent, there was no problem.
When the Icom equipped plane is not lead and only does very short transmissions
(i.e. checking in), there is no problem.
Interestingly, my portable radio, which has manual squelch adjustment, could receive
transmission when my 250XL is silent.
You ask 1. Did you have the flight (as in all aircraft in formation) change to
a different frequency and see if it changed what was going on? Yes, the issue
had occurred on 121.20, 123.30, 135.95 & 135.97.
You ask 2. When it was happening, did you try YOUR radio on a different frequency
to see if you could hear anyone else? As in an ASOS transmission, tower,
ground, ATC, anyone? Yes, changing frequency on my 250XL does not restore its
ability to receive transmission. When the issue occurred in the beginning of
a flight, I could resolve the issue by pressing SQ; however, after about 10 to
15 minutes, pressing the SQ does nothing.
Your help is greatly appreciated.
Robin
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=482160#482160
Message 2
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| Subject: | Re: Garmin 250XL Squelch Issue |
Hi Mark,
You got it right and thank you for your explanation of the SQ button..
There were a few times I stopped hearing the lead while he was
transmitting. After a while (after my 250XL was nice and hot), I can no
longer hear any transmission from any one.
I can now correctly describe my problem when I send in my 250XL to Garmin
for repair.
Your help is greatly appreciated. Thanks again.
Robin
On Wed, Aug 8, 2018 at 12:05 PM Bitterlich, Mark G CIV NAVAIR, WD <
mark.bitterlich@navy.mil> wrote:
> mark.bitterlich@navy.mil>
>
> Ok, your description is making some assumptions about what is going on,
> which I'd advise we not do. I'm still less than clear on EXACTLY what is
> happening, although we are starting to zero in.
>
> So ... are you saying that when the Icom equipped airplane is close to
> you, and makes a rather long transmission ... something happens.
> Question: Do you stop hearing him WHILE he is transmitting, in that he is
> talking, you hear him, then WHILE HE IS TALKING, YOU STOP HEARING HIM?
> And then you can't hear ANYONE else? Go through this with me again step
> by step. Or tell me I've got it correct please.
>
> The most important statement you made was that you could press the SQ
> switch initially and things would work, and then pressing it again later
> on..... results in nothing being heard on ANY freq.
>
> Let's talk about that SQ button on your radio so you are clear what it
> actually does. It does not "reset" ANYTHING. It simply turns Squelch
> OFF. With squelch off, and the volume turned up, you should be able to
> hear static in your headset. Try this on the ground with the engine not
> running, before your flight. Just push the SQ once, listen for static,
> push it again and the static goes away. So it is a SWITCH ... push once,
> it turns off squelch, push again it turns it back on.
>
> I think you are getting the wrong idea of what "Automatic Squelch" really
> is. It is not something that is "adjusting itself" in flight. It is in
> fact nothing more than a comparator circuit which measures signal to noise
> ratio, and when the signal to noise ratio achieves a PRESET LEVEL, the
> speaker is turned on. That is ALL that it does. Pushing the SQ switch
> just turns the speaker on ALL THE TIME and bypasses this circuit. Pushing
> the SQ button does nothing to "reset" or "readjust" anything. It just
> bypasses the circuit that turns your speaker on automatically when there is
> a strong enough signal.
>
> Now that you understand this, a light bulb should be starting to glow a
> little bit.
>
> The situation is simply this: You are close to an aircraft with a strong
> transmitter. I don't believe it has anything to do with the other aircraft
> having an Icom radio, OTHER THAN, it has been my experience that the Icom
> Radios put out a tad more power than some others, and also they tend to
> modulate right at 100%, which is actually a good thing. But the point is
> that YOUR aircraft is in the near field of this transmission, and that
> means your receiver is being hit with a ton of energy. And ... I don't
> believe it is handling it too well at all. Meaning, I think that there is
> a component in your receiver that is being overloaded and then stops
> functioning. I base this on one very important point:
>
> You say that once it happens, you can push the SQ button one time, and you
> hear no static, or transmissions from anyone else. We must be clear on the
> fact that you now understand that the SQ button is a SWITCH. Hit it once,
> and it turns the speaker on all the time, hit it again and it goes back to
> allowing the circuit to turn on the speaker. You need to be very clear on
> this, and listen to it on the ground with the engine not running, so you
> can fully understand the function.
>
> If you then go flying again consider pushing the SQ one time, and let it
> run with the speaker on all the time. It is annoying I know, but do it.
> Then join and tell the guy in lead with the Icom to transmit for 30 seconds
> or so. If while he is talking, his signal just disappears and then you
> can't receive anything... then my friend, your receiver has a problem, and
> should be returned for service. And you will need to be very clear on the
> gripe: "When flying formation with another aircraft and he transmits for
> 30 seconds or so, the receiver stops receiving.... anything and
> everything.... and then works properly again once it is turned off, cools
> down, and is turned on again." A tech will immediately know how to test
> for that with a SigGen.
>
> The above is true, only if I fully understand what you are telling me.
> If there are further details, the above might be wrong! :-) I suspect
> that the first RF amplifier in the receiver, or possibly the first mixer
> circuit is failing to operate properly. But if I have all this right....
> there is no question that your receiver has an issue that needs to be
> fixed. (Sorry to tell you that).
>
> Mark
>
>
> -----Original Message-----
> From: owner-yak-list-server@matronics.com <
> owner-yak-list-server@matronics.com> On Behalf Of Robin Hou
> Sent: Tuesday, August 07, 2018 3:29 PM
> To: yak-list@matronics.com
> Subject: [Non-DoD Source] Yak-List: Re: Garmin 250XL Squelch Issue
>
>
> Hi Mark,
>
> Sorry, I should have been more clear. I say that the Icom would "trip my
> 250XL squelch"; what I mean is when the Icom transmits, my 250XL auto
> squelch function would adjust itself to a point that I can no longer hear
> any transmission from any radio. It occurred mostly when the Icom equipped
> plane is flying lead which requires transmissions lasting for a 30 seconds
> or so at a time. When the Icom equipped plane is not lead and stays radio
> silent, there was no problem. When the Icom equipped plane is not lead and
> only does very short transmissions (i.e. checking in), there is no problem.
>
> Interestingly, my portable radio, which has manual squelch adjustment,
> could receive transmission when my 250XL is silent.
>
> You ask 1. Did you have the flight (as in all aircraft in formation)
> change to a different frequency and see if it changed what was going on?
> Yes, the issue had occurred on 121.20, 123.30, 135.95 & 135.97.
>
> You ask 2. When it was happening, did you try YOUR radio on a different
> frequency to see if you could hear anyone else? As in an ASOS
> transmission, tower, ground, ATC, anyone? Yes, changing frequency on my
> 250XL does not restore its ability to receive transmission. When the issue
> occurred in the beginning of a flight, I could resolve the issue by
> pressing SQ; however, after about 10 to 15 minutes, pressing the SQ does
> nothing.
>
> Your help is greatly appreciated.
>
> Robin
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=482160#482160
>
>
Message 3
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| Subject: | Anyone know of a A&P that can work on Yaks in Seattle? |
Looking for a A&P familiar with the M14-P in the Seattle area. I need some hoses
changed and parts installed from M14-P.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=482198#482198
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