Today's Message Index:
----------------------
1. 02:59 AM - Re: Dual Comm Transmitter Problem (John Rippengal)
2. 07:16 AM - Re: Audio input to video camera (Noel Loveys)
3. 07:20 AM - Re: Dual Comm Transmitter Problem (Noel Loveys)
4. 08:13 AM - Re: Dual Comm Transmitter Problem (John)
5. 08:54 AM - Re: Dual Comm Transmitter Problem (Hopperdhh@aol.com)
6. 12:38 PM - Re: Dual Comm Transmitter Problem (John Rippengal)
7. 03:26 PM - Re: Dual Comm Transmitter Problem (Doug McNutt)
8. 05:35 PM - Re: Dual Comm Transmitter Problem (Noel Loveys)
9. 07:14 PM - Re: Dual Comm Transmitter Problem (John)
Message 1
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| Subject: | Re: Dual Comm Transmitter Problem |
--> Avionics-List message posted by: "John Rippengal" <j.rippengal@cytanet.com.cy>
Connecting a VSWRmeter in the feed line involves:
unplugging the antenna from the radio;
plugging the input to the meter into the output of the radio which will
require a short lead with the appropriate plug (probably a BNC plug) on it
to suit the radio output;
plugging the antenna coax into the output of the VSWR meter (you will
probably need a UHF to BNC adapter for that assuming the antenna lead has a
BNC plug on it.)
Radio hams will be familiar with this nomenclature.
It is a simple operation and you would be well advised to get a VSWR meter
yourself for future reference once you have seen how it is done.
If the tests show the transmitters and antennas are ok as far as power and
VSWR is concerned then you will have to look at the audio input circuits. I
can't quite remember, but didn't you say you had been trying to incorporate
a mobile phone into the system?? Or was that somone else??
John
> --> Avionics-List message posted by: "John" <joplin1@charter.net>
>
> Several of you have advised me that an a VSWR check should be my next
> step. (my radios bench checked good, receivers are excellent, but my
> transmissions are weak and scratchy)
>
> I contacted a gentleman who has a 'ham' business in town. He deals pretty
> much with the shortwave spectrum, not the VHF. He told me that he doesn't
> have the MFJ-259B meter. But, he feels sure that I can find someone in a
> local club who does. He mentioned that the meter needs to be inserted
> into the feed line between the radio and the antenna and he suspects
> adapters might be required to do that. Before I start trying to find
> someone with a MFJ-295B, what should I know about inserting the meter into
> the feed line? Remember, I am Radio Illiterate. I just want to be sure
> that I can provide the 'ham' with the required adapters and any other
> information that he might need. It is possible that will have no
> experience with aircraft radios.
>
> Thanks,
>
> John Linman
Message 2
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| Subject: | Audio input to video camera |
--> Avionics-List message posted by: "Noel Loveys" <noelloveys@yahoo.ca>
That record jack is probably a 1-V p-p line out jack it should work properly
when plugged into your line input on your camera. You will probably have
problems if you plug it into the mic input. Check the spec on the "Record"
out in the documentation for your audio panel.
Noel
> -----Original Message-----
> From: owner-avionics-list-server@matronics.com
> [mailto:owner-avionics-list-server@matronics.com] On Behalf
> Of KD4ZHA@aol.com
> Sent: Thursday, June 22, 2006 1:54 AM
> To: avionics-list@matronics.com
> Subject: Re: Avionics-List: Audio input to video camera
>
>
> --> Avionics-List message posted by: KD4ZHA@aol.com
>
> My intercom has a "record" jack. I just used a standard rat
> shack patch
> cord, and impedence wasn't a problem. Picked up everything
> that goes to the
> headset. leave the squelch down to pickup engine sounds,
> wind noise, etc. (gets a
> little annoying, though). Do a short video and check it.
>
>
>
>
>
>
>
>
>
>
>
>
>
Message 3
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| Subject: | Dual Comm Transmitter Problem |
--> Avionics-List message posted by: "Noel Loveys" <noelloveys@yahoo.ca>
I expect the patch cables will only have to be BNC The ham should have more
patch cables than Lipton got tea bags. You can also check with the local
telco if they offered a VHF radio phone service. Be sure their technicians
have everything and more to do the job!
Noel
> -----Original Message-----
> From: owner-avionics-list-server@matronics.com
> [mailto:owner-avionics-list-server@matronics.com] On Behalf Of John
> Sent: Thursday, June 22, 2006 2:13 AM
> To: avionics-list@matronics.com
> Subject: Re: Avionics-List: Dual Comm Transmitter Problem
>
>
> --> Avionics-List message posted by: "John" <joplin1@charter.net>
>
> Several of you have advised me that an a VSWR check should be
> my next step. (my radios bench checked good, receivers are
> excellent, but my transmissions are weak and scratchy)
>
> I contacted a gentleman who has a 'ham' business in town. He
> deals pretty much with the shortwave spectrum, not the VHF.
> He told me that he doesn't have the MFJ-259B meter. But, he
> feels sure that I can find someone in a local club who does.
> He mentioned that the meter needs to be inserted into the
> feed line between the radio and the antenna and he suspects
> adapters might be required to do that. Before I start trying
> to find someone with a MFJ-295B, what should I know about
> inserting the meter into the feed line? Remember, I am Radio
> Illiterate. I just want to be sure that I can provide the
> 'ham' with the required adapters and any other information
> that he might need. It is possible that will have no
> experience with aircraft radios.
>
> Thanks,
>
> John Linman
> To locate a local ham, look for a house with an "antenna
> farm"! Many hams
> these days have the MFJ-259B which is a very good tool for
> checking VSWR
> across the VHF band. This is a very easy test to do. One
> only needs to plug the
> coax from the antenna into the unit and turn a knob.
>
>
> Dan Hopper K9WEK
> Walton, IN
>
>
>
>
>
>
>
>
>
>
>
>
>
>
Message 4
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| Subject: | Re: Dual Comm Transmitter Problem |
--> Avionics-List message posted by: "John" <joplin1@charter.net>
In answer to your question "If the tests show the transmitters and antennas are
ok as far as power and VSWR is concerned then you will have to look at the audio
input circuits. I can't quite remember, but didn't you say you had been trying
to incorporate a mobile phone into the system?? Or was that somone else??"
My LightSPEED headset does have the capability to connect to a cell phone. I experimented
with it and found that my calls out were too weak and broken for others
to understand. My cell phone receiver was excellent though. I have acknowledge
that cell phone use in the air is illegal so please no more responses
to that.
I no longer have a cell phone connected to the system. My question: Is it possible
that my experiment with the cell phone damaged the system? The radios bench
check good.
I do have a Sigtronics Intercom system with stereo music capability. It can take
music from a portable disk player and pipes it through the intercom. I seldom
use it, but perhaps that circuit is faulty.
Thanks,
John
----- Original Message -----
From: John Rippengal
To: avionics-list@matronics.com
Sent: Thursday, June 22, 2006 2:54 AM
Subject: Re: Avionics-List: Dual Comm Transmitter Problem
--> Avionics-List message posted by: "John Rippengal" <j.rippengal@cytanet.com.cy>
Connecting a VSWRmeter in the feed line involves:
unplugging the antenna from the radio;
plugging the input to the meter into the output of the radio which will
require a short lead with the appropriate plug (probably a BNC plug) on it
to suit the radio output;
plugging the antenna coax into the output of the VSWR meter (you will
probably need a UHF to BNC adapter for that assuming the antenna lead has a
BNC plug on it.)
Radio hams will be familiar with this nomenclature.
It is a simple operation and you would be well advised to get a VSWR meter
yourself for future reference once you have seen how it is done.
If the tests show the transmitters and antennas are ok as far as power and
VSWR is concerned then you will have to look at the audio input circuits. I
can't quite remember, but didn't you say you had been trying to incorporate
a mobile phone into the system?? Or was that somone else??
John
> --> Avionics-List message posted by: "John" <joplin1@charter.net>
>
> Several of you have advised me that an a VSWR check should be my next
> step. (my radios bench checked good, receivers are excellent, but my
> transmissions are weak and scratchy)
>
> I contacted a gentleman who has a 'ham' business in town. He deals pretty
> much with the shortwave spectrum, not the VHF. He told me that he doesn't
> have the MFJ-259B meter. But, he feels sure that I can find someone in a
> local club who does. He mentioned that the meter needs to be inserted
> into the feed line between the radio and the antenna and he suspects
> adapters might be required to do that. Before I start trying to find
> someone with a MFJ-295B, what should I know about inserting the meter into
> the feed line? Remember, I am Radio Illiterate. I just want to be sure
> that I can provide the 'ham' with the required adapters and any other
> information that he might need. It is possible that will have no
> experience with aircraft radios.
>
> Thanks,
>
> John Linman
Message 5
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| Subject: | Re: Dual Comm Transmitter Problem |
--> Avionics-List message posted by: Hopperdhh@aol.com
John,
The MFJ-259B needs an SO-239 to BNC adapter and then perhaps male-to-male or
female-to-female BNC connectors to allow it to connect to your antenna
somehow. I have found that you can sometimes take a BNC and butcher it up to
connect directly into the radio tray (after removing the radio) to test the whole
feedline plus antenna.
The 259B does not use the radio for the signal source to measure VSWR, it
has its own signal generator and counter, so it does not go inline like a
standard SWR meter. (VSWR and SWR are used interchangeably here. Also the SWR
meter is sometimes called an SWR bridge -- same thing.) The 259B only tests
the antenna and coax beyond where you connect it in. I think you have already
tested the radio, so this way you can isolate the problem.
Dan Hopper K9WEK
RV-7A
In a message dated 6/22/2006 12:47:29 A.M. Eastern Daylight Time,
joplin1@charter.net writes:
I contacted a gentleman who has a 'ham' business in town. He deals pretty
much with the shortwave spectrum, not the VHF. He told me that he doesn't
have the MFJ-259B meter. But, he feels sure that I can find someone in a
local club who does. He mentioned that the meter needs to be inserted into the
feed line between the radio and the antenna and he suspects adapters might be
required to do that. Before I start trying to find someone with a MFJ-295B,
what should I know about inserting the meter into the feed line? Remember, I
am Radio Illiterate. I just want to be sure that I can provide the 'ham' with
the required adapters and any other information that he might need. It is
possible that will have no experience with aircraft radios.
Thanks,
John Linman
Message 6
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| Subject: | Re: Dual Comm Transmitter Problem |
--> Avionics-List message posted by: "John Rippengal" <j.rippengal@cytanet.com.cy>
No intention of giving any lectures on legality John. It's just that I am
puzzled by both receiver paths being ok which tends to suggest the
antenna/feeders may also be ok. If both transmitters are giving poor results
then the common thing is the audio source and if you have been 'playing'
with it there may have been some damage done inadvertently.
J
> --> Avionics-List message posted by: "John" <joplin1@charter.net>
>
> In answer to your question "If the tests show the transmitters and
> antennas are ok as far as power and VSWR is concerned then you will have
> to look at the audio input circuits. I can't quite remember, but didn't
> you say you had been trying to incorporate a mobile phone into the
> system?? Or was that somone else??"
>
> My LightSPEED headset does have the capability to connect to a cell phone.
> I experimented with it and found that my calls out were too weak and
> broken for others to understand. My cell phone receiver was excellent
> though. I have acknowledge that cell phone use in the air is illegal so
> please no more responses to that.
>
> I no longer have a cell phone connected to the system. My question: Is
> it possible that my experiment with the cell phone damaged the system?
> The radios bench check good.
>
> I do have a Sigtronics Intercom system with stereo music capability. It
> can take music from a portable disk player and pipes it through the
> intercom. I seldom use it, but perhaps that circuit is faulty.
>
> Thanks,
>
> John
>
Message 7
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| Subject: | Re: Dual Comm Transmitter Problem |
--> Avionics-List message posted by: Doug McNutt <douglist@macnauchtan.com>
At 22:34 +0300 6/22/06, John Rippengal wrote:
>No intention of giving any lectures on legality John. It's just that I am puzzled
by both receiver paths being ok which tends to suggest the antenna/feeders
may also be ok. If both transmitters are giving poor results then the common
thing is the audio source and if you have been 'playing' with it there may have
been some damage done inadvertently.
>J
Agreed. A good thing to look for is always some single thing that can affect both
devices giving trouble.
In this case it's the incoming audio or possibly the aircraft power. It is unlikely
that both antenna systems have failed simultaneously. Well they are on the
belly. Were the wheels down?
The radio shop that did the bench testing. Did they use the microphone out of the
aircraft? Did they say anything about modulation level? For many radios it's
supposed to be adjusted for the microphone to be used though it's not terribly
important with newer radios.
Are there different microphone jacks in the aircraft? Have they all been tried?
Is there another microphone?
Can you be sure you're not transmitting on both radios at the same time? Did you
turn one completely off. If both radios are tuned to the same frequency you
can expect noise from the receiver associated with the transmitter not in use.
Its input at the antenna will surely drive it into saturation. You should be
sure that's not being switched into your audio system.
Get rid of all audio stuff by using a "standard" carbon microphone. If you have
jacks that bypass the audio selector panel use them. If not consider installing
some. Two radios with only one way to get to them doesn't support the extra
reliability of having two.. Some microphones have been known to be sensitive
to radiation from a transmitter. An unshielded wire on a headset can easily do
that especially if the mic is not real carbon but one of the newer electrets
or dynamic devices that require a transistor for operation.
With the antennas on the belly that VSWR test being discussed may be compromised
especially if the ground below is electrically conductive - grass or wet. It
won't be there while flying.
Are you sure you don't have aircraft power problems? The radios draw more current
while transmitting and might be causing a drop in line voltage. Measure it.
Check for changes in transmitted quality with the engine revved up. Check with
the landing light and pitot heat on to make for more drain on the bus.
--
--> The best programming tool is a soldering iron <--
Message 8
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| Subject: | Dual Comm Transmitter Problem |
--> Avionics-List message posted by: "Noel Loveys" <noelloveys@yahoo.ca>
Find some one with a beastie called a Bird Wattmeter. Read the forward
power and then reverse the slug to read the reflected power. This will
check the power amp of your transmitter at the same time as checking your
antenna system.
While you are at it ask if any one has a Cushman station analyzer. This
will do much much more. Any one who has this equipment will know how to use
it. If your radios are certified they may not want to go near them. Not
because of lack of knowledge but because of legal implications.
Noel
> -----Original Message-----
> From: owner-avionics-list-server@matronics.com
> [mailto:owner-avionics-list-server@matronics.com] On Behalf
> Of Hopperdhh@aol.com
> Sent: Thursday, June 22, 2006 1:23 PM
> To: avionics-list@matronics.com
> Subject: Re: Avionics-List: Dual Comm Transmitter Problem
>
>
> --> Avionics-List message posted by: Hopperdhh@aol.com
>
>
>
>
> John,
>
> The MFJ-259B needs an SO-239 to BNC adapter and then perhaps
> male-to-male or
> female-to-female BNC connectors to allow it to connect to
> your antenna
> somehow. I have found that you can sometimes take a BNC and
> butcher it up to
> connect directly into the radio tray (after removing the
> radio) to test the whole
> feedline plus antenna.
>
> The 259B does not use the radio for the signal source to
> measure VSWR, it
> has its own signal generator and counter, so it does not go
> inline like a
> standard SWR meter. (VSWR and SWR are used interchangeably
> here. Also the SWR
> meter is sometimes called an SWR bridge -- same thing.) The
> 259B only tests
> the antenna and coax beyond where you connect it in. I
> think you have already
> tested the radio, so this way you can isolate the problem.
>
> Dan Hopper K9WEK
> RV-7A
>
>
> In a message dated 6/22/2006 12:47:29 A.M. Eastern Daylight Time,
> joplin1@charter.net writes:
>
> I contacted a gentleman who has a 'ham' business in town.
> He deals pretty
> much with the shortwave spectrum, not the VHF. He told me
> that he doesn't
> have the MFJ-259B meter. But, he feels sure that I can
> find someone in a
> local club who does. He mentioned that the meter needs to
> be inserted into the
> feed line between the radio and the antenna and he suspects
> adapters might be
> required to do that. Before I start trying to find someone
> with a MFJ-295B,
> what should I know about inserting the meter into the feed
> line? Remember, I
> am Radio Illiterate. I just want to be sure that I can
> provide the 'ham' with
> the required adapters and any other information that he
> might need. It is
> possible that will have no experience with aircraft radios.
>
> Thanks,
>
> John Linman
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
Message 9
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| Subject: | Re: Dual Comm Transmitter Problem |
--> Avionics-List message posted by: "John" <joplin1@charter.net>
I am starting to get bogged down with technical stuff that I don't understand.
I think my best solution now is to spend the $$ and take my aircraft to an Avionics
Shop. I have printed out all of your comments and suggestions. They should
be very helpful when I discuss my transmitter problems with avionics technicians.
I will stay after them until they have considered all of the possibilities
that you have mentioned.
Actually, my radios are still useable ... just not as good as I'd like. I will
refrain from asking for radio checks in the future because I know the answer
will be "weak and scratchy". Instead, I will just press on as if I don't have
a problem. I have found that all of the controlling agencies I deal with read
me well enough so that they don't complain.
Thanks again to all of you.
John
----- Original Message -----
From: Noel Loveys
To: avionics-list@matronics.com
Sent: Thursday, June 22, 2006 5:32 PM
Subject: RE: Avionics-List: Dual Comm Transmitter Problem
--> Avionics-List message posted by: "Noel Loveys" <noelloveys@yahoo.ca>
Find some one with a beastie called a Bird Wattmeter. Read the forward
power and then reverse the slug to read the reflected power. This will
check the power amp of your transmitter at the same time as checking your
antenna system.
While you are at it ask if any one has a Cushman station analyzer. This
will do much much more. Any one who has this equipment will know how to use
it. If your radios are certified they may not want to go near them. Not
because of lack of knowledge but because of legal implications.
Noel
> -----Original Message-----
> From: owner-avionics-list-server@matronics.com
> [mailto:owner-avionics-list-server@matronics.com] On Behalf
> Of Hopperdhh@aol.com
> Sent: Thursday, June 22, 2006 1:23 PM
> To: avionics-list@matronics.com
> Subject: Re: Avionics-List: Dual Comm Transmitter Problem
>
>
> --> Avionics-List message posted by: Hopperdhh@aol.com
>
>
>
>
> John,
>
> The MFJ-259B needs an SO-239 to BNC adapter and then perhaps
> male-to-male or
> female-to-female BNC connectors to allow it to connect to
> your antenna
> somehow. I have found that you can sometimes take a BNC and
> butcher it up to
> connect directly into the radio tray (after removing the
> radio) to test the whole
> feedline plus antenna.
>
> The 259B does not use the radio for the signal source to
> measure VSWR, it
> has its own signal generator and counter, so it does not go
> inline like a
> standard SWR meter. (VSWR and SWR are used interchangeably
> here. Also the SWR
> meter is sometimes called an SWR bridge -- same thing.) The
> 259B only tests
> the antenna and coax beyond where you connect it in. I
> think you have already
> tested the radio, so this way you can isolate the problem.
>
> Dan Hopper K9WEK
> RV-7A
>
>
> In a message dated 6/22/2006 12:47:29 A.M. Eastern Daylight Time,
> joplin1@charter.net writes:
>
> I contacted a gentleman who has a 'ham' business in town.
> He deals pretty
> much with the shortwave spectrum, not the VHF. He told me
> that he doesn't
> have the MFJ-259B meter. But, he feels sure that I can
> find someone in a
> local club who does. He mentioned that the meter needs to
> be inserted into the
> feed line between the radio and the antenna and he suspects
> adapters might be
> required to do that. Before I start trying to find someone
> with a MFJ-295B,
> what should I know about inserting the meter into the feed
> line? Remember, I
> am Radio Illiterate. I just want to be sure that I can
> provide the 'ham' with
> the required adapters and any other information that he
> might need. It is
> possible that will have no experience with aircraft radios.
>
> Thanks,
>
> John Linman
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
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