[Boatanchors] Speech Amp Again

[Carl]

----- Original Message ----- 
From: "Bob Macklin" <macklinbob at msn.com>
To: "Carl" <km1h at jeremy.mv.com>; "rbethman" <rbethman at comcast.net>; 
"Barrie Smith" <barrie at centric.net>
Cc: <boatanchors at mailman.qth.net>
Sent: Wednesday, November 19, 2008 2:59 PM
Subject: Re: [Boatanchors] Speech Amp Again


>A shielded twisted pair should have the shield only connected to ground 
>at
> one end so the shield does not carry current. It is most common to 
> ground
> the shield at the load end.
>
> Bob Macklin
> K5MYJ
> Kent (Seattle), Wa,
> "Real Radios Glow in the Dark"


That only holds true on a battle ship where a real ground is established 
(;

In the typical ham shack its a crap shoot if there is any ground and the 
only load is the one the ham has on....hic

That was the reason for my suggesting trying different ends.

Carl
KM1H

>
> ----- Original Message ----- 
> From: "Carl" <km1h at jeremy.mv.com>
> To: "rbethman" <rbethman at comcast.net>; "Barrie Smith" 
> <barrie at centric.net>
> Cc: <boatanchors at mailman.qth.net>
> Sent: Wednesday, November 19, 2008 11:53 AM
> Subject: Re: [Boatanchors] Speech Amp Again
>
>
>> Shielding may create a ground loop problem between units. If hum is a
>> problem try the shielding with grounding at one end at a time and 
>> then
>> both. As John said twisting is the most important step, as it cancels
>> common mode problems.
>>
>> Im using twisted # 16 cloth covered wire (just like in the old days) 
>> to
>> both of my modulator decks with no hum pickup.
>>
>> Carl
>> KM1H
>>
>>
>> ----- Original Message ----- 
>> From: "rbethman" <rbethman at comcast.net>
>> To: "Barrie Smith" <barrie at centric.net>
>> Cc: <boatanchors at mailman.qth.net>
>> Sent: Wednesday, November 19, 2008 2:04 PM
>> Subject: Re: [Boatanchors] Speech Amp Again
>>
>>
>> > Barrie,
>> >
>> > I DEFINITELY shield them.
>> >
>> > Bob - N0DGN
>> >
>> > Barrie Smith wrote:
>> >> Good Day:
>> >>
>> >> Should the leads from the speech amplifier, or the matching
>> >> transformer, to the input of the HT-4B be shielded?
>> >>
>> >> 73, Barrie, W7ALW
>> >>
>> >
>> > -- 
>> > Bob - NØDGN
>> >
>> > _______________________________________________
>> >
>>
>> _______________________________________________
>>
>
>