Today's Message Index:
----------------------
1. 12:20 AM - Yahoo! Auto Response (xrayperformance@yahoo.com)
2. 12:45 AM - Re: Com audio issues (John Rippengal)
3. 06:53 AM - Re: Com audio issues (Hopperdhh@aol.com)
4. 08:11 PM - Radio audio troubles ()
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Yahoo! Auto Response |
Thank you for for contacting us. We'll try to get back to you within the next business
day. For a quicker response, please leave your item number so that we
can futher assist you as well. JDM TEAM appriciate your business.Business Hours:
M-F 10AM-7PM PST Sat&Sun Close
********LOOK FOR LAMBO DOOR 90DEGREE KIT***********
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=013&sspagename=STRK%3AMESE%3AIT&viewitem=&item=230092008705&rd=1,1
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Com audio issues |
It could be an impedance problem. But before doing anything else it would be
as well to check that there is nothing peculiar about the com2 input. Change
the Becker and Icom inputs round to make sure the problem either stays with
com2 (in which case the problems is with the audio panel) or changes over to
com1 (in which case the problem is with the Becker)
It is rather poor practice to just mechanically parallel the outputs.
Normally the audio panel would provide a simple op amp circuit which would
enable the outputs to be combined without affecting each other at all. Are
you sure it does just parallel them all up? If it does then I would expect
any output to be attenuated noticeably when paralleling multiple others.
John
Subject: Avionics-List: Com audio issues
>
> Hi Gurus,
>
> It's been awhile, but I hope all is well with you all.
>
> I'm having audio issues with my new Becker 4201 #2 com and was wondering
> if
> you could help.
>
> The issue is the output audio from the radio whenever there is another
> radio
> switched into the same output. As soon as any other input is selected on
> the audio panel at the same time, the com#2 volume goes very very low and
> is
> overpowered. Sidetone during transmit seems un-affected as does the audio
> of
> the other sources selected - only the Com2 audio drops down. By
> itself...the radio sounds fine, and operates properly.
>
> The #1 com (iCom A200) works fine and is nice and loud with any number of
> inputs selected on the audio panel (KA-134). Adding additional inputs has
> little to no affect on com1 volume. It works great - as it should.
>
> According to the KA-134 schematics, the only thing it's doing with the
> phone
> outputs from the radios is mechanically switching them (no electronics)
> together to a single output line to the intercom. Because of this, I was
> wondering if the impedance differences of the radios are a problem.
> However, I have no real understand of the magic involved.
>
> They are as follows according to the respective docs:
> Com1 iCom - 500 ohms
> Com2 Becker - 600 ohms
> Eng mon - 560 ohms
> Nav KN-53 - 500 ohms
>
> I still puzzled why Com1 has no issues with any number of other inputs,
> and
> Com2 does.
>
> Any ideas? I have schematics for the KA-134 if you want to see it...but
> for
> this, it's just switches.
>
> Thanks for any help!
>
> James Redmon
> Berkut13 N97TX
>
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Com audio issues |
In a message dated 2/14/2007 3:51:25 AM Eastern Standard Time,
j.rippengal@cytanet.com.cy writes:
It is rather poor practice to just mechanically parallel the outputs.
Normally the audio panel would provide a simple op amp circuit which would
enable the outputs to be combined without affecting each other at all. Are
you sure it does just parallel them all up? If it does then I would expect
any output to be attenuated noticeably when paralleling multiple others.
John
James,
I agree with John. Actually the output impedance of each unit is probably
not 500 or 600 ohms. It could be as small as 1 ohm or as large as 600 ohms, but
designed to drive a 500 or 600 ohm load. If you put a resistor of about 200
ohms in series with each unit, then you give each one a chance to compete with
the others.
Dan Hopper
RV-7A
Retired EE
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Radio audio troubles |
Hi Gurus,
It's been awhile, but I hope all is well with you all.
I'm having audio issues with my new Becker 4201 #2 com and was wondering if
you could help.
The issue is the output audio from the radio whenever there is another radio
switched into the same output. As soon as any other input is selected on
the audio panel at the same time, the com#2 volume goes very very low and is
overpowered. Sidetone during transmit seems un-affected as does the audio of
the other sources selected - only the Com2 audio drops down. By
itself...the radio sounds fine, and operates properly.
The #1 com (iCom A200) works fine and is nice and loud with any number of
inputs selected on the audio panel (KA-134). Adding additional inputs has
little to no affect on com1 volume. It works great - as it should.
According to the KA-134 schematics, the only thing it's doing with the phone
outputs from the radios is mechanically switching them (no electronics)
together to a single output line to the intercom. Because of this, I was
wondering if the impedance differences of the radios are a problem.
However, I have no real understanding of the magic involved here.
They are as follows according to the respective docs:
Com1 iCom - 500 ohms
Com2 Becker - 600 ohms
Eng mon - 560 ohms
Nav KN-53 - 500 ohms
RST Marker Receiver - unknown
I am still puzzled why Com1 has no issues with any number of other inputs,
and
Com2 does....impedance differences and all.
Any ideas? I have schematics for the KA-134 if you want to see it...but for
this, it's just mechanical switches.
Thanks for any help!
James Redmon
Berkut13 N97TX
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|