#x27;m sorry Bacon I can't
remember for sure. It's another one that probably needs some help.
John, WA5BXO
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Donald Chester
Sent: Sunday, January 02, 2005 5:11 PM
To: amradio@mailman.qth.net
Su
If you measure current from the filament transformer center tap to ground,
you'll have not only cathode current, but plate current, as well. Just
look
over at the grid current meter, subtract that from the plate meter, and
there's
your plate current, AND it's in a nearly ground potential posit
But.. To get the correct input power (required in broadcasting) you must
measure plate current not cathode current. Properly insulated meters are
safe and reliable.
The way to get around that is to return the grid and screen circuits to the
cathode of the tube, and place the plate meter in
> Just remember that when you put the meter in the cathode circuit it measured
> combined plate & screen current.
>
> Bob Macklin
> K5MYJ/7
> Seattle, Wa.
>
> "REAL RADIOS GLOW IN THE DARK"
or Grid/cathode current, in the case of triodes ;-)
73 = Best Regards,
-Geoff/W5OMR
ussion of AM Radio"
Sent: Saturday, January 01, 2005 10:11 PM
Subject: Re: [AMRadio] You Won't Believe This
> John, thank you for this.
>
> Collins engineers did not adhere to safe operating practice when they
placed
> the 800 ma meter in the positive lead going to the R.F.
> But.. To get the correct input power (required in broadcasting) you must
> measure plate current not cathode current. Properly insulated meters are
> safe and reliable. I agre its either static or magnetic field problem.
If you measure current from the filament transformer center tap to gro
www.collinsra.com
Nets: 3805 Khz, Monday/Wednesdays 8 PM EDST
14250 Khz Saturday, 12 Noon EDST
- Original Message -
From: "John Coleman, ARS WA5BXO" <[EMAIL PROTECTED]>
To: "'Discussion of AM Radio'"
Sent: Sunday, January 02, 2005 12:31 AM
Subject:
t; <[EMAIL PROTECTED]>
To: "Discussion of AM Radio"
Sent: Sunday, January 02, 2005 8:18 AM
Subject: Re: [AMRadio] You Won't Believe This
> It would be interesting to see exactly how much current is flowing
> through the meter. Try hooking the lead from the smoothing choke
7;Discussion of AM Radio'"
Sent: Sunday, January 02, 2005 12:31 AM
Subject: RE: [AMRadio] You Won't Believe This
I gather from the text about the HV meter and current meter that the
current meter is above ground by 4000 Volts. I know that there are a
lot of special mounting dev
: 3805 Khz, Monday/Wednesdays 8 PM EDST
14250 Khz Saturday, 12 Noon EDST
- Original Message -
From: "KC8OPP Roger S." <[EMAIL PROTECTED]>
To: "Discussion of AM Radio"
Sent: Sunday, January 02, 2005 7:57 AM
Subject: Re: [AMRadio] You Won't Believe This
gt; Publisher of the Collins Journal
> > Secretary to the Collins Radio Association
> > www.collinsra.com
> > Nets: 3805 Khz, Monday/Wednesdays 8 PM EDST
> > 14250 Khz Saturday, 12 Noon EDST
> >
> > - Original Message -
> > From: "
ECTED]>
To: "Discussion of AM Radio"
Sent: Sunday, January 02, 2005 2:11 AM
Subject: Re: [AMRadio] You Won't Believe This
> John, thank you for this.
>
> Collins engineers did not adhere to safe operating practice when they
placed
> the 800 ma meter in the positive le
;
Sent: Saturday, January 01, 2005 11:58 PM
Subject: Re: [AMRadio] You Won't Believe This
> Dave, I am not familiar with the 20V, but the problem you are describing
> suggests a stray magnetic field around the meter might cause the
deflection.
> Have you changed any other wiring
ginal Message-
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED] On Behalf Of David Knepper
> Sent: Saturday, January 01, 2005 5:31 PM
> To: Discussion of AM Radio; Collins Mail List
>
> Subject: [AMRadio] You Won't Believe This
>
> That is right, only one lead co
Subject: [AMRadio] You Won't Believe This
That is right, only one lead connected and the meter is reading negative
current. I switched this lead to the negative post and the meter still
deflects downward past zero.
ROTECTED]>
To: "Discussion of AM Radio"
Sent: Saturday, January 01, 2005 8:45 PM
Subject: Re: [AMRadio] You Won't Believe This
> Sorry John, but that is not the answer. I did clean the face. Besides
> that, the meters of the 20V-3 are behind a glass panel to avoid accide
:05 PM
Subject: Re: [AMRadio] You Won't Believe This
> Static charge on the case? Disassemble and wash carefully with fine dish
> soap. Dry carefully with a paper towel and let it set a day until all
moisture is
> sure to be gone. Take precautions not to build up another charge when
>
Static charge on the case? Disassemble and wash carefully with fine dish
soap. Dry carefully with a paper towel and let it set a day until all moisture
is
sure to be gone. Take precautions not to build up another charge when
reinstalling.
You might just wipe the face carefully and see if that
I own a Collins 20V-3 broadcast transmitter that is at the Collins Radio
Center.
The transmitter has been restored and worked perfectly after modifying it to
160 meters.
Now, the plate current meter (0-800 ma.) is reading to the left of "0" with
only the high voltage lead from the smoothing choke
19 matches
Mail list logo
