Today's Message Index:
----------------------
1. 12:46 AM - Re: Headset microphone level reducer (Jay Hyde)
2. 05:05 AM - Weak and Static on Transmission ()
3. 05:13 AM - Re: Grand rapids cs02 / cs01 amp sensor (bob noffs)
4. 05:55 AM - Re: Headset microphone level reducer (Etienne Phillips)
5. 11:02 AM - SWR Meter (ROGER & JEAN CURTIS)
6. 01:58 PM - Re: SWR Meter (Robert L. Nuckolls, III)
7. 02:44 PM - Re: SWR Meter OOPS (Robert L. Nuckolls, III)
8. 02:51 PM - Re: SWR Meter (Noel Loveys)
9. 02:52 PM - Re: SWR Meter (Noel Loveys)
10. 04:29 PM - Re: SWR Meter (Robert L. Nuckolls, III)
11. 06:45 PM - Re: SWR Meter (ROGER & JEAN CURTIS)
Message 1
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Subject: | Headset microphone level reducer |
Hi there Etienne,
The MGL radio can have the microphone levels independently set- do you have
the V10 or V6 radio?
Jay
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Etienne
Phillips
Sent: 02 January 2012 08:29 PM
Subject: AeroElectric-List: Headset microphone level reducer
<etienne.phillips@gmail.com>
Hi All
I have two dissimilar headsets that have very different microphone output
levels. The one headset is an oldish basic Avcomm model, and the other is a
new child-sized one. My MGL radio/intercom doesn't have the ability to
reduce the volume of the new headset adequately.
I've never worked with electret microphones before, so am not sure how to
build a signal reducer. I have noticed that they are polarity sensitive,
which leads me to expect some phantom power is required...?
I need to reduce the volume by about 15dB (according to the MGL radio) to
match the Avcomm. Ideally, I'd like to be able to build a passive circuit
that I can squeeze into the headset itself, rather than an interface box or
off-the-shelf device. This will allow me to use the new headset in other
aircraft as the Avcomm's seem to play nicely with other major brands.
If anyone has some insight, I'd be most appreciative!
Thanks
Etienne
Message 2
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Subject: | Weak and Static on Transmission |
1/21/2012
Hello Bill Bradburry, You wrote: "These radio problems at a Class C airport
have made me afraid to fly."
I consider the following items to be mandatory equipment in my experimental
amateur built airplane both during phase one testing and subsequently:
1) One of the readily available, portable, battery powered hand held VHF
communications radios along with both its original rechargeable battery
(recently recharged) and a spare fitted battery case filled with alkaline
batteries.
2) An adapter that allows me to plug my headset into the portable radio.
3) A means to temporarily connect the antenna connection of the portable
radio into one of the airplane's more capable antennae. Note that:
a) Actually using this temporary antenna connection is optional at the time
of intended use and initial attempts at communication may be made using the
antenna mounted on the portable radio itself.
b) Using this temporary antenna connection and the hand held radio for
trouble shooting may aid in locating the source of your communication
problem.
Following the above philosophy may take you out of the "afraid to fly
category".
When you eventually solve this problem please let us know what the problem
was -- thanks.
'OC' Baker Says: "The best investment we can make is the time and effort to
gather and understand knowledge."
PS: You also wrote: "I sent my radio back to have it checked out and nothing
was found."
A "ground checks OK" result does not guarantee that the connection between
the radio and your airplane is also OK. Have you been able to borrow an
identical radio and test it in your airplane?
==========================================================
Time: 05:42:24 AM PST US
From: "Bill Bradburry" <bbradburry@bellsouth.net>
Subject: RE: AeroElectric-List: Re: Weak and Static on Transmission
Well, to further clarify this problem. I seem to be able to hear ok on the
ground while taxiing around the airport, but after I leave the airport the
reception gets really bad. At first I thought it was a problem with the
approach frequency because that is where it would first start up. It was a
loud hiss in the headphones so loud that I could not hear ATC. In fact, I
have made two NORDO landings as a result on this loud hiss. I sent my radio
back to have it checked out and nothing was found. All this trouble is at
below 5000 ft and fine weather. I am flying off my 40 hours (22 so far) and
am only flying in good weather. These radio problems at a Class C airport
have made me afraid to fly. ATC could take some action against me if it
continues.
Lancair has an all carbon Legacy available but this one is all fiberglass
with the exception of the horizontal stabilizer, which is carbon. The
antenna is inside the fuselage about 4+feet forward of the stabilizer.
The bottom and rear half of the plane is in primer. The rest of the plane
is bare fiberglass. The primer ends just about at the location of the
antenna on the fuselage. I don't know if this would have an effect on the
static on the plane or not. I would have had to consider static wicks a
long time earlier in the build in order to install bonding wire. It is too
late now AFAIK.
Bill B
Message 3
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Subject: | Re: Grand rapids cs02 / cs01 amp sensor |
i put mine on the cable from the battery after the starter so it
monitored supply to the panel.
bob noffs
On Fri, Jan 20, 2012 at 11:46 PM, chris Sinfield <
chris_sinfield@yahoo.com.au> wrote:
> chris_sinfield@yahoo.com.au>
>
> Hi all
> > I am installing a Grand Rapids J6000 EIS in my aircraft.
> > > Where have people wired the amp current sensor? and through whit size
> > > wire was it?
> > > There are 2 different current sensors and they are for different size
> > > wires?
> > >
> > > you can use the CS-01 or CS-02 or amps. the most important difference
> > > is the size wire that is allowed for each.
> > > the CS-01 100amp can fit up to a #4 wire and the CS-02 50amp can only
> > > fit up to #6 wire. so if you're using a big battery cable most
> > > people require the #4 wire and the CS-01.
> > >
> > > So which one to use and where did you fit it in the elec circuit on a
> > > Jab3300?
> > >
> > > Chris
> > > Zodiac XL
> > > Jab 3300
> > >
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=364425#364425
>
>
Message 4
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Subject: | Re: Headset microphone level reducer |
Hi Jay
I've got a V10 radio, and I've already maxed out the settings, turning the pax
headset all the way down, and it still was too loud. I don't want to turn up the
Pilot's mic, as it is set correctly, matching the incoming radio volume.
I haven't gotten around to trying out Bob's suggestion yet, but I'm pretty sure
it'll work.
Thanks
Etienne
On 21 Jan 2012, at 10:43 AM, Jay Hyde wrote:
>
> Hi there Etienne,
>
> The MGL radio can have the microphone levels independently set- do you have
> the V10 or V6 radio?
>
> Jay
Message 5
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I have a Vintage Sears SWR / FS meter which appears to be
the same as the Cal Com Model 9856. Can this be used to check the antenna
on aircraft nav com radios? If so, how do I set it up for use?
Roger
Message 6
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At 12:57 PM 1/21/2012, ROGER & JEAN CURTIS wrote:
> I have a Vintage Sears SWR / FS meter which appears to be
>the same as the Cal Com Model 9856. Can this be used to check the antenna
>on aircraft nav com radios? If so, how do I set it up for use?
>
> Roger
>
This is no doubt an excellent example of a
transmission line sampling reflectometer. Dozens
of products of this genre' were manufactured
and they are quite common.
Bob . . .
Message 7
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Subject: | Re: SWR Meter OOPS |
Sorry, hit the 'send' function before finishing the
reply. Ignore the previous posting . . .
At 12:57 PM 1/21/2012, ROGER & JEAN CURTIS wrote:
> I have a Vintage Sears SWR / FS meter which appears to be
>the same as the Cal Com Model 9856. Can this be used to check the antenna
>on aircraft nav com radios? If so, how do I set it up for use?
>
> Roger
This is no doubt an excellent example of a
directional coupler sampling reflectometer. Dozens
of products of this genre' were manufactured
and they are quite common.
Emacs!
A general description of this device can be secured
at:
http://en.wikipedia.org/wiki/SWR_meter
They are quite effective over the range of 2 to
perhaps 30 MHz. To be useful, the length of transmission
line inside must be a small fraction of a wavelength
at the frequency of interest. In this case, 126 Mhz.
When you study the design of a Watt/SWR meter suited
for VHF . . .
Emacs!
The sampling is in a single "slug" that can be
rotated to present complimentary forward and reverse
power samples.
Emacs!
The slug contains a miniaturized version of the directional
coupler sampling sampling loops found in your SWR meter.
Here's a photo of a miniaturized version of your SWR meter
optimized for VHF/UHF service. The loops are about 1/2"
long.
Emacs!
So the short answer is the instrument you have is useful
at Citizen's band frequencies and below. You need something
tailored to VHF to do any serious work with your ship's
antennas. Something like this
Emacs!
which can be had for about $60 off eBay. It's optimized
for VHF and will produce more useful readings.
For an more in-dept explanation you can browse a compendium of
publications at:
http://www.aeroelectric.com/articles/RF_PWR_Meter/
and in particular an article at:
http://www.aeroelectric.com/articles/RF_PWR_Meter/Directional%20Coupler%20pa0nhc.pdf
which describes a modification of instruments like yours
that extends their useful range into VHF/UHF regions.
Bob . . .
Message 8
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I wouldn't use this type of SWR meter on anything north of 50 mHz. Find a
ham or telco tech who used to work on microwave equipment to test your
antenna. Such a person might also advise you on things like ground planes
and antenna location. For certified aircraft the work should be signed off
by a certified avionics shop.
Noel
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: January 21, 2012 6:24 PM
Subject: Re: AeroElectric-List: SWR Meter
<nuckolls.bob@aeroelectric.com>
At 12:57 PM 1/21/2012, ROGER & JEAN CURTIS wrote:
> I have a Vintage Sears SWR / FS meter which appears to be
>the same as the Cal Com Model 9856. Can this be used to check the antenna
>on aircraft nav com radios? If so, how do I set it up for use?
>
> Roger
>
This is no doubt an excellent example of a
transmission line sampling reflectometer. Dozens
of products of this genre' were manufactured
and they are quite common.
Bob . . .
Message 9
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I forgot to say there was at least one Heathkit VHF SWR/FS meter on E-Bay a
few minutes ago. Not the highest quality meter but it will put you in the
ball park.
Noel
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: January 21, 2012 6:24 PM
Subject: Re: AeroElectric-List: SWR Meter
<nuckolls.bob@aeroelectric.com>
At 12:57 PM 1/21/2012, ROGER & JEAN CURTIS wrote:
> I have a Vintage Sears SWR / FS meter which appears to be
>the same as the Cal Com Model 9856. Can this be used to check the antenna
>on aircraft nav com radios? If so, how do I set it up for use?
>
> Roger
>
This is no doubt an excellent example of a
transmission line sampling reflectometer. Dozens
of products of this genre' were manufactured
and they are quite common.
Bob . . .
Message 10
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At 03:54 PM 1/21/2012, you wrote:
<nuckolls.bob@aeroelectric.com>
At 12:57 PM 1/21/2012, ROGER & JEAN CURTIS wrote:
I have a Vintage Sears SWR / FS meter which appears to be
the same as the Cal Com Model 9856. Can this be used to check the antenna
on aircraft nav com radios? If so, how do I set it up for use?
Roger
This is no doubt an excellent example of a
transmission line sampling reflectometer. Dozens
of products of this genre' were manufactured
and they are quite common. (insert OOPS here
when I sent the response too soon).
I fumbled the ball when I changed the subject line
and my complete response didn't get tacked onto this
thread. Be sure to get the whole 9-yard response under
a similar subject line.
Bob . . .
Message 11
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At 12:57 PM 1/21/2012, ROGER & JEAN CURTIS wrote:
I have a Vintage Sears SWR / FS meter which appears to be
the same as the Cal Com Model 9856. Can this be used to check the antenna
on aircraft nav com radios? If so, how do I set it up for use?
Roger
This is no doubt an excellent example of a
transmission line sampling reflectometer. Dozens
of products of this genre' were manufactured
and they are quite common. (insert OOPS here
when I sent the response too soon).
I fumbled the ball when I changed the subject line
and my complete response didn't get tacked onto this
thread. Be sure to get the whole 9-yard response under
a similar subject line.
Bob . . .
Thanks Guys,
It appears that I have a unit suitable for the CB band.
Since they are reasonably priced I will purchase a new one in the correct
frequency band.
Roger
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