I've forgotten to add, that you must realign the driver and final
grid section for the upper bands (best if you perform a complete RF
re-alignment as per manual), where you may note the worst tracking
difference after C13 capacitor change.
Good luck
Guillermo - LU8EYW.
GGLL wrote:
Are your final tubes fine after C13 short?; that failure will turn
very positive final tube's grid bias, which causes an indeed high
plate current. Check them before you go to the shop. If I don't miss,
C13 was a 100 pF rectangular old style mica cap. You could replace
them with two 47 pF, 500V NP0 disc ceramics in parallel as I did in
several 101's with good results.
Best regards
Guillermo - LU8EYW.
Jerry Pittman wrote:
Correction!!! Sorry Rick, I spoke to soon. I pulled the C13 cap
from the
circuit and found that it had shorted. You were dead on for the
diagnosis.
Now to go to the electronics shop tomorrow.
Thanks a Million!!
73 Jerry
WD4OIX
----- Original Message ----- From: "Jerry Pittman"
<jerryp49@worldnet.att.net>
To: "R_Davis" <WD8JJA@arrl.net>; <yaesu@contesting.com>
Sent: Sunday, February 15, 2004 5:59 PM
Subject: Re: [Yaesu] Problem in FT-101E -100v Circuit (Jerry Pittman)
Thanks for the tip Rick. I checked that cap and it appears okay, so
the
search goes on.
Jerry
----- Original Message ----- From: "R_Davis" <WD8JJA@arrl.net>
To: <yaesu@contesting.com>
Sent: Saturday, February 14, 2004 12:41 PM
Subject: [Yaesu] Problem in FT-101E -100v Circuit (Jerry Pittman)
Check the coupling capacitor, C13, between the 12BY7A and the finals.
Rick, WD8JJA.
----- Original Message -----
From: <yaesu-request@contesting.com>
To: <yaesu@contesting.com>
Sent: Saturday, February 14, 2004 12:00 PM
Subject: Yaesu Digest, Vol 14, Issue 9
Send Yaesu mailing list submissions to
yaesu@contesting.com
To subscribe or unsubscribe via the World Wide Web, visit
http://lists.contesting.com/mailman/listinfo/yaesu
or, via email, send a message with subject or body 'help' to
yaesu-request@contesting.com
You can reach the person managing the list at
yaesu-owner@contesting.com
When replying, please edit your Subject line so it is more specific
than "Re: Contents of Yaesu digest..."
Today's Topics:
1. Problem in FT-101E -100v Circuit (Jerry Pittman)
----------------------------------------------------------------------
Date: Fri, 13 Feb 2004 12:41:26 -0500
From: "Jerry Pittman" <jerryp49@worldnet.att.net>
To: <yaesu@contesting.com>
Subject: [Yaesu] Problem in FT-101E -100v Circuit
Message-ID: <006e01c3f258$9b485ac0$6101a8c0@JerryPittman>
Content-Type: text/plain;
charset="iso-8859-1"
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
Precedence: list
Reply-To: Jerry Pittman <jerryp49@worldnet.att.net>
Message: 1
Hello to all,
HELP! I wonder if anyone has run into this problem:
My 101E was just idling along while I was working on the computer the
=
other evening, when I started smelling something hot. I shot the rig
=
off immediately and found that the bias control (VR1) on the
voltage =
control board (PB1547B) had over heated, as well as the (2) 10K =
resistors on either side of the control.
When I check the voltage at pin 5 of the 1547 board, I found that it
was
=
getting -160v instead of -100v. I went to the Rectifier board
(PB1076B)
=
and made tests there. When I disconnected the lead from the -100v =
terminal, the voltage shows -60v but with it is connected it shows =
-160v. With the lead disconnected I also tested it for AC voltage
and
=
it shows 125vac as well as -60vdc.
I checked all the components on the 1076B board and found all okay,
but
=
just to be sure I hadn't missed something, I put in a used PB1076B
board
=
and found all of the same readings. I had already checked all of the
=
other voltages coming and going from the 1076B and all are correct =
except the -100v. The voltages from all of the transformer taps
appear
=
to be within range as well.
Does anyone have an Idea or run into this before?
Thanks in advance for any responses.
Jerry
WD4OIX
jerryp49@att.net------------------------------
_______________________________________________
Yaesu mailing list
Yaesu@contesting.com
http://lists.contesting.com/mailman/listinfo/yaesu
End of Yaesu Digest, Vol 14, Issue 9
************************************
_______________________________________________
Yaesu mailing list
Yaesu@contesting.com
http://lists.contesting.com/mailman/listinfo/yaesu
_______________________________________________
Yaesu mailing list
Yaesu@contesting.com
http://lists.contesting.com/mailman/listinfo/yaesu
_______________________________________________
Yaesu mailing list
Yaesu@contesting.com
http://lists.contesting.com/mailman/listinfo/yaesu
|