[Heathkit] HW101

Thu, 11 Jul 2002 18:20:47 -0400

I just looked at the schematic and believe I would check the potentiometer
which is to zero the S-meter.  If the pot is open or has a bad solder
connection, it could create the fault you are experiencing.

Good luck and 73, Mike N4NT

----- Original Message -----
From: <[email protected]>
To: <[email protected]>
Cc: <[email protected]>; <[email protected]>
Sent: Thursday, July 11, 2002 5:13 PM
Subject: [Heathkit] HW101

----- Original Message -----
From: "R. Schmitz" <[email protected]>
To: <[email protected]>
Sent: Friday, July 05, 2002 11:35 AM
Subject: Help HW-101

> Hello List!
> Got a cheap HW-101 on a flea market.
> Made a realignment but have still a problem. It is not possible to get
> S-meter 0.
> Even with the variable resistor for S-meter 0 fully adjustet, S-meter is
far
> left.Also audio in RX-mode sounds a bit "rough".
> Could not check audio in TX-mode, because in TX there are around mic-input
> several "modifications" that i have to rebuild. But that is another story.
CW
> is full output all bands.
> Any idea about the S-meter 0 ?
> Best of luck with the green equipment.
> Randolf, DL6KAI
>

Hello and thank You for Your help!
Have checked V3 and V4 and replaced them with a pair out of my working
SB102,
but the bug is not fixed. Next i will see at the resistors, but  a first
checkup with
the "OhmMeter" in the circuit did not show a failure.
So, I believe there is a lot work to do, but due to QRL, it will need a
period of time to continue.
Bye the way, I still have not the HW101 manual and there are some
differences
between
HW101 and my SB102. Maybe one of You can mail me the Voltage Charts and
thex-ray views
of the IF circuit board and the Modulator circuit board?
If I have continued repair, I will pass the results to the list.
These were the helpful messages from You all, maybe You are interested to
read them together…..
Best 73 and again thank You, de Randolf, DL6KAI

The first thing I would do is replace V3 which is the tube from which the
S meter indicates.

Failing that, I'd suggest looking at the voltages on both sides of the
meter (to ground).  The meter reads across a fixed voltage (set by the
adjust control) and the cathode voltage of V3.  You can see which is
wrong.

Ed
K1ZOK

Randolf: take a look at
http://webpages.charter.net/dalewentz/kb9jja/heathkit/
Look under modifications
HW101 mod collection Steve ray K4JPN
It list your problem and many other common ones.
Jim
KC0HEW

Hello Randolf! I once had one with a similar problem. In the case of mine, I
remember that it turned out to be a resistor value that had changed. Check
the resistors in meter-zero circuit. They'll sometimes change with age.

I helped a friend with another that had the same problem, and in that case
the problem was the tube. I don't recall which tube it is, but try swapping
out the one that drives the meter. You may be able to switch it with another
in the rig.

I think you'll be very pleased with your 101 once you get it going. It
really is a nice radio!

Best of luck, and let me know how it turns out --

Steve AA4BW

For the S meter check the value of R106, R107.
For the distortion problem change R123 from 470 ohm to
100 ohm, change C17 from 12 pf to 100 pf, change R113
from 1K ohm to 10K ohm, change C119 from 500 pf to
.001 ufd, change C306 from .005 ufd to .01 ufd.

73,  Mark  WB8JKR

There was an article published in CQ Magazine within the past year or two
titled Restoring the HW-101.  It includes information on the S-meter.  The
whole article is something you should have in general.

I have it scanned into JPG files (six files, one page to a file) averaging
200k+ each.  Let me know if you'd like me to email them to you.

73 de W2GERry

For the S meter check the value of R106, R107.
For the distortion problem change R123 from 470 ohm to
100 ohm, change C17 from 12 pf to 100 pf, change R113
from 1K ohm to 10K ohm, change C119 from 500 pf to
.001 ufd, change C306 from .005 ufd to .01 ufd.

73,  Mark  WB8JKR

Those damn S meters are a bit tricky Randolf....Try replacing the tube
(6au6)
that "drives" the circuit. Different tubes cause the S meter to behave
differently. Also, check the archives as there was Heath fixes for that
problem involving changing a 100K resistor to 1 watt from 1/2 watt. I just
solved the same problem on my SB-102 by changing some out of spec resistors
in the circuit and swapping in a new tube!

Mark V. Johnson VE3DJU/VE3DDI
>

Hi .....You may try switching the 6au6 tubes around....v-3 and the other
tubes have a lot to do with meter zero...If you have a manual it will
tell you the tubes that control the s-meter.....Jim

Hi .....You may try switching the 6au6 tubes around....v-3 and the other
tubes have a lot to do with meter zero...If you have a manual it will
tell you the tubes that control the s-meter.....Jim

If you can, check the 6AU6 tubes (valves) at V3 and V4.  Some of the
original HW-101 kits were supplied with mis-marked tubes.  They actually
had 4-volt filaments and will not zero or stabilize when operating.  Try
swapping with other 6AU6 tubes in the HW-101, or from another source, to
see if that's the problem.

                                     Ed Mosher, [email protected]

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