HW 101

[Steve & Anne Ray]

Hi Stu,

Thanks for your note.  I found the 6EA8 developed oscillations (spurs) most
notable on 10 and 15 meters.  Heath came out with a fix with some bypassing
caps, but I prefer the 6CQ8.  Over the years I bought a lot of 6EA8s to
cure the spur problem.  You could see the output power not varying a whole
lot, yet you were getting good modulation reports.   Going with the 6CQ8
which is a triode/tetrode solved the problem and I found gave a lot more
audio drive.  I use a D-104 with my HW-101.  My HW-101 is the main rig and
other then my recent ventures into QRP the only rig.  In fact in 35 years
of hamming I have only had 3 rigs and the last when I built the HW-101 21
years ago.

As far as your question on R-202 do not remove R-202 that is in your
SB-101, apparently Heath used a different numbering scheme between the
various rigs.  The resistor to remove is a 10K locate between the output of
V3 and pin 2 of V5a.  (Obviously you must replace this with a piece of
wire)  I checked my SB-102 manual and it does not show this resistor,
unfortunately I do not have a SB-101 manual so I cannot check it.  To
further help you this resistor goes across two circuit boards the IF
circuit board to the bandpass circuit board.  In the SB-102 manual it shows
these two points connected by shielded wire.

The article in Hints and Kinks was in the collection of Hints and Kinks
published in 1978.  If anyone wants a copy send me a large SASE and I will
be glad to copy and mail back.

73,

Steve Ray    K4JPN   ex K1VKW   HW-101, HW-8,
SWL 30-40, Pixie II, NC 38S and Heath Kit fan


----------
> From: w6cux at juno.com
> To: sbralr at WORLDNET.ATT.NET
> Subject: Re: HW 101
> Date: Monday, December 15, 1997 11:01 PM
>
> Hi Steve,
> I read your comments re the HW101 and I wonder if you know the
> corresponding resistor to R202 in the SB101??  It can't be the same cuz
> R202 in the SB101 is the cathode resistor of the 2nd xmtr mixer and
> shorting it out would short out the LMO.  Also which issue was the Hints
> & Kinks in in 1978??
>
> I tried your idea of replacing V1 with a 6CQ8 (you had mentioned it some
> time ago) and I do seem to get a little more AGC action.  But then I
> already seem to have enough audio gain.  I run the gain pot at 12
> o'clock.
>
> Now for my hint-of-the-day.  If you can't find a 6HS6, try a 6HR6.  It
> has about the same gm, Rp and noise figure and is available for $4.  The
> differance is that it is a remote cutoff rather than a sharp cutoff which
> changes the gain distrubution during AGC.  The 6HR6 will directly replace
> the 6AU6 in the RF ampl. (V10 in the SB101).
>
> Do you know anything about the SB640? You may have read my posting where
> I asked about how Heath hooked the SB640 to the SB101. I'm still looking
> for info on that subject.  I was able to connect a SB301 LMO to the -101
> but the way I did it is not too good in that I can't operate split
> (though I'm not sure why I'd want to).
>
> If you did read my posting -- I solved the second paragraph problem.
> Turned out it was the differance in hetrodyne xtal frequencies which
> meant that the -301 & -101 would be on a differant receive frequency with
> the same LMO setting.
>
> Thanks es 73,
> Stu Lyon, W6CUX
> Winnetka, CA
> -ARRL Life Member
> -98 Spectrum Defense Sponsor

--- --- --- --- --- --- --- --- --- --- --- --- --- --
To subscribe: listserv at listserv.tempe.gov
and in body: subscribe HEATH yourfirstname yourlastname
To unsubscribe:  listserv at listserv.tempe.gov
and in body: signoff HEATH
Archives for HEATH: http://www.tempe.gov/archives
--- --- --- --- --- --- --- --- --- --- --- --- --- --