K3 Microphone Cable

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K3 Microphone Cable

Steve Kercel
I am getting ready to buy a K3 and a MH-2 hand mike.

Due to the layout of my station, I need to add a 6-foot-long extension
cable from the K3 mike jack to the actual mike connection. I have the
necessary connectors on hand. but I'm wondering about the 8-conductor cable.

Is a piece of CAT-5 data cable (four twisted pairs of #24 wire) suitable
for this purpose? Are there any special precautions I need to observe?

TNX & 73,

Steve
AA4AK


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Re: K3 Microphone Cable

Matt Zilmer
Ethernet cable is gonna look oogly - but it's cheap.  The twisted
pairs should provide a little shielding.  The jacket will not be very
smooth unless it's made from some material like TPE (rubberized
thermoplastic).  These are usually called Plenum Cables because of the
rated temperature range.  They're also round instead of the
PVC-jacket-gets-twisted (and otherwise deformed) characteristic.

I would advise a fully shielded mic HOT and RETURN cable. The Pro
stuff, like Shure used to source in the 1970's.  Dunno who sells this
class of mic cable now, but there was a distributor in Burbank, CA a
long time ago that used to service the west coast NBC studio.  I would
look along those lines.

At this station, there's been no trouble with the cabling for a Heil
Goldline that Heil itself provides.  It's a little pricey for someone
that is mostly DIY, but your TX audio will never suffer from it.  So
even though you want to use the MH2, an extension in one of these two
classes might cut it for you.  You might look into Heil Audio; they
may source an extension for the MH2 or its equivalent.

I believe the idea would be to minimize the impedance from source to
load, while keeping any stray RF away from the MIC input to the K3.

At this station, I have a lifetime supply of the Shure cable.  It's
double-shielded with both a woven layer and a thick foil.  That, and a
few ferrite collars cover the audio here from RFI.  Audio reports are
good too, better than anyone has a right to expect.

73,
matt W6NIA

On Wed, 04 May 2011 23:57:48 -0400, you wrote:

>I am getting ready to buy a K3 and a MH-2 hand mike.
>
>Due to the layout of my station, I need to add a 6-foot-long extension
>cable from the K3 mike jack to the actual mike connection. I have the
>necessary connectors on hand. but I'm wondering about the 8-conductor cable.
>
>Is a piece of CAT-5 data cable (four twisted pairs of #24 wire) suitable
>for this purpose? Are there any special precautions I need to observe?
>
>TNX & 73,
>
>Steve
>AA4AK
>
>
>______________________________________________________________
>Elecraft mailing list
>Home: http://mailman.qth.net/mailman/listinfo/elecraft
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>This list hosted by: http://www.qsl.net
>Please help support this email list: http://www.qsl.net/donate.html
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Re: K3 Microphone Cable

Joe Subich, W4TV-4

Steve,

>> Is a piece of CAT-5 data cable (four twisted pairs of #24 wire)
>> suitable for this purpose? Are there any special precautions I need
>> to observe?

It will work fine.  Just be sure to use one pair for mic and mic return
(pin1 and pin 7) and one pair for PTT and ground (pin 2 and pin 8).
The other pins can be any wires but using twisted pairs for mic/mic
return and PTT/Ground will provide the best balancing to reduce any
hum/RFI issues with the unshielded cable.

If you can find shielded CAT5, connect the shield to the connector
*SHELL* only on both ends (do not connect it to either mic return
(pin 7) or ground (pin 8).

73,

    ... Joe, W4TV


> On Wed, 04 May 2011 23:57:48 -0400, you wrote:
>
>> I am getting ready to buy a K3 and a MH-2 hand mike.
>>
>> Due to the layout of my station, I need to add a 6-foot-long extension
>> cable from the K3 mike jack to the actual mike connection. I have the
>> necessary connectors on hand. but I'm wondering about the 8-conductor cable.
>>
>> Is a piece of CAT-5 data cable (four twisted pairs of #24 wire) suitable
>> for this purpose? Are there any special precautions I need to observe?
>>
>> TNX&  73,
>>
>> Steve
>> AA4AK
>>
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
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Re: K3 Microphone Cable

Jim Brown-10
On 5/4/2011 10:27 PM, Joe Subich, W4TV wrote:
> It will work fine.  Just be sure to use one pair for mic and mic return
> (pin1 and pin 7) and one pair for PTT and ground (pin 2 and pin 8).
> The other pins can be any wires but using twisted pairs for mic/mic
> return and PTT/Ground will provide the best balancing to reduce any
> hum/RFI issues with the unshielded cable.

EXACTLY RIGHT.  Twisted pair, in general, provides very good rejection
of hum, buzz, and RFI, and CAT5/6 is VERY VERY GOOD twisted pair.  
Shielding doesn't hurt, but it doesn't help either. Twisting is enough.
The important thing is to follow Joe's advice on wiring.

73, Jim K9YC
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