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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>I had a used GD-17 and also built a GDA-19 when I was 16.
The GD-17 had Bonner sticks and had a large, 2 deck metal cased receiver that
was fairly heavy even by late 60’s standards. Not too reliable because of
intermittent receiver problems, but the rest of it was fine. I didn’t
think it was a Kraft design, but maybe it was. Servos were Kraft KPS-9
cases, with electronics that I think were probably Kraft or very closely
derived from Kraft. The RF section was apparently a Heathkit design, and as
for the encoder electronics, I always assumed it was influenced by Kraft, of
was designed for them by Kraft, but was not necessarily a direct copy.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>The GD-19 was on 72 Mhz and had the closed gimbal Kraft sticks, with
what appeared to be a Heath RF section and encoder. Again, maybe derived
from or done by Kraft? The receiver was Heathkit designed and really
kicked butt for its day. It was single conversion, with a ceramic filter
IF amplifier and If I remember right, it used a series of SCS (silicon controlled
switches) in the decoder. It was very selective for a single conversion
receiver, and very sensitive too. In fact, several of us who flew at
Mitchell Field in Hempstead, NY were able to fly in an interference environment
caused by a local UHF TV transmitter (right off the corner of the runway) that was
close enough and strong enough to make a servo connected to just a battery jitter
if you held it up and moved it around a little bit. Kraft was sending
engineers out to Mitchell to figure out why their Series 7x stuff was crashing,
while the Heathkits were impervious. (Other brands had trouble
too). Several of us even demonstrated that we could fly with the antenna
up only one stage (obviously we only did this at a safe altitude and with a
helper ready to extend it if control was lost). Heck of a radio for
1971. <o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>They eventually came out with some really nice IC based servos
in the KPS-11, KPS-12 and I suppose other Kraft cases. I never built any
of their later radios, but a lot of local guys did and they just worked great.
I miss those days.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Ed<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'>
<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>
nsrca-discussion-bounces@lists.nsrca.org
[mailto:nsrca-discussion-bounces@lists.nsrca.org] <b>On Behalf Of </b>steve
hannah<br>
<b>Sent:</b> Monday, June 22, 2009 4:24 PM<br>
<b>To:</b> General pattern discussion<br>
<b>Subject:</b> Re: [NSRCA-discussion] Heathkits<o:p></o:p></span></p>
</div>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal style='margin-bottom:12.0pt'>My Dad is Bill Hannah, who used
to be the VP of Engineering for Heath Company. He was the one that
introduced the RC equipment into the Heath lineup. As a kid I built A LOT
of Heathkits. I learned how to debug all sorts of electronic problems and
lead to my engineering career. Of course, I learned to fly on Heathkit
radios. <br>
<br>
Heath radios were a kit version of the Kraft radios. They had some of
their own designs in the later years as well. <br>
<br>
I believe the engineer you are talking about is Mike Geishin (SP?). I'm
not sure of his exact title when he was at Heath, but he was instrumental in their
radio designs. He flew with my Dad back in the day.<br>
<br>
By the way, I still have the Heath stereo system I built when I was in high
school. It survived the endless torment I subjected it to in my college
years. Good stuff.<br>
<br>
Steve Hannah.<o:p></o:p></p>
<div>
<p class=MsoNormal>On Mon, Jun 22, 2009 at 12:51 PM, <<a
href="mailto:ronlock@comcast.net">ronlock@comcast.net</a>> wrote:<o:p></o:p></p>
<div>
<div>
<p><span style='font-family:"Arial","sans-serif";color:black'>I'm still using a
Heath ESV, one of the few that does single nicads.<o:p></o:p></span></p>
<p><span style='font-family:"Arial","sans-serif";color:black'>Though, I have
not found much use for the timing light for a while - <VBG><o:p></o:p></span></p>
<p><span style='font-family:"Arial","sans-serif";color:black'> <o:p></o:p></span></p>
<p><span style='font-family:"Arial","sans-serif";color:black'>Ron Lockhart<br>
<br>
<br>
----- Original Message -----<br>
From: "Mark Atwood" <<a href="mailto:atwoodm@paragon-inc.com"
target="_blank">atwoodm@paragon-inc.com</a>><br>
To: "General pattern discussion" <<a
href="mailto:nsrca-discussion@lists.nsrca.org" target="_blank">nsrca-discussion@lists.nsrca.org</a>><br>
Sent: Monday, June 22, 2009 3:37:44 PM GMT -05:00 US/Canada Eastern<br>
Subject: Re: [NSRCA-discussion] Servo Signals<br>
<br>
Agree on missing the stores and the kits. That was my introduction to
Elec. Engineering and programming which has ended up putting a lot of food on
my table over the past 20 years.<br>
<br>
-----Original Message-----<br>
From: <a href="mailto:nsrca-discussion-bounces@lists.nsrca.org" target="_blank">nsrca-discussion-bounces@lists.nsrca.org</a>
[mailto:<a href="mailto:nsrca-discussion-bounces@lists.nsrca.org"
target="_blank">nsrca-discussion-bounces@lists.nsrca.org</a>] On Behalf Of Pete
Cosky<br>
Sent: Monday, June 22, 2009 1:35 PM<br>
To: General pattern discussion<br>
Subject: Re: [NSRCA-discussion] Servo Signals<br>
<br>
I used to live at the Heathkit store in Pittsburgh when I was a kid. Never <br>
used their RC stuff but I did build one of their robots. I miss their kits.<br>
----- Original Message ----- <br>
From: "mike mueller" <<a href="mailto:mups1953@yahoo.com"
target="_blank">mups1953@yahoo.com</a>><br>
To: "General pattern discussion" <<a
href="mailto:nsrca-discussion@lists.nsrca.org" target="_blank">nsrca-discussion@lists.nsrca.org</a>><br>
Sent: Monday, June 22, 2009 1:31 PM<br>
Subject: Re: [NSRCA-discussion] Servo Signals<br>
<br>
<br>
><br>
> Mark there's a guy Mike --- sorry I forgot his last name that comes to the
<br>
> contests that was an engineer for heathkit. He'll be at the Jim Hubbard <br>
> this weekend. I'll tell him you had a Heathkit he will get a kick out of <br>
> that. Mike<br>
><br>
> --- On Mon, 6/22/09, Atwood, Mark <<a
href="mailto:atwoodm@paragon-inc.com" target="_blank">atwoodm@paragon-inc.com</a>>
wrote:<br>
><br>
>> From: Atwood, Mark <<a href="mailto:atwoodm@paragon-inc.com"
target="_blank">atwoodm@paragon-inc.com</a>><br>
>> Subject: Re: [NSRCA-discussion] Servo Signals<br>
>> To: "'<a href="mailto:nsrca-discussion@lists.nsrca.org"
target="_blank">nsrca-discussion@lists.nsrca.org</a>'" <br>
>> <<a href="mailto:nsrca-discussion@lists.nsrca.org" target="_blank">nsrca-discussion@lists.nsrca.org</a>><br>
>> Date: Monday, June 22, 2009, 12:13 PM<br>
>> The old heathkit servos (mine anyway)<br>
>> were kit versions of the Kraft K-15 servos.<br>
>><br>
>> In fact the whole radio I believe was a Kraft design.<br>
>> -Mark<br>
>> --------------------------<br>
>> Sent from my BlackBerry Wireless Handheld<br>
>><br>
>><br>
>> ----- Original Message -----<br>
>> From: <a href="mailto:nsrca-discussion-bounces@lists.nsrca.org"
target="_blank">nsrca-discussion-bounces@lists.nsrca.org</a><br>
>> <<a href="mailto:nsrca-discussion-bounces@lists.nsrca.org"
target="_blank">nsrca-discussion-bounces@lists.nsrca.org</a>><br>
>> To: General pattern discussion <<a
href="mailto:nsrca-discussion@lists.nsrca.org" target="_blank">nsrca-discussion@lists.nsrca.org</a>><br>
>> Sent: Mon Jun 22 13:06:18 2009<br>
>> Subject: Re: [NSRCA-discussion] Servo Signals<br>
>><br>
>><br>
>> Yes, as long as they are clean. That is the problem, it<br>
>> depends on contact between two components and the friction<br>
>> wears them out.<br>
>><br>
>> I remember years ago that the large heathkit (and possibly<br>
>> some Kraft) servos used variable capacitors for feedback.<br>
>> not much to wear.<br>
>><br>
>> Ok, Jay, how long ago were the "days" you were talking<br>
>> about? :-)<br>
>><br>
>> Bob R.<br>
>><br>
>><br>
>> --- On Sun, 6/21/09, Jay Marshall <<a
href="mailto:lightfoot@sc.rr.com" target="_blank">lightfoot@sc.rr.com</a>><br>
>> wrote:<br>
>><br>
>><br>
>><br>
>> I remember from my days in control systems theory that the<br>
>> analog computers were faster and more accurate than the IBM<br>
>> big iron computers. Analog pots are still cheaper, lighter,<br>
>> and higher resolution than digital encoders – as long as<br>
>> they are clean…<br>
>><br>
>><br>
>><br>
>><br>
>><br>
>><br>
>> No virus found in this incoming message.<br>
>> Checked by AVG - <a href="http://www.avg.com" target="_blank">www.avg.com</a><br>
>> Version: 8.5.339 / Virus Database: 270.12.81/2188 - Release<br>
>> Date: 06/19/09 17:56:00<br>
>><br>
>><br>
>> _______________________________________________<br>
>> NSRCA-discussion mailing list<br>
>> <a href="mailto:NSRCA-discussion@lists.nsrca.org" target="_blank">NSRCA-discussion@lists.nsrca.org</a><br>
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target="_blank">http://lists.nsrca.org/mailman/listinfo/nsrca-discussion</a><br>
><br>
><br>
><br>
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target="_blank">http://lists.nsrca.org/mailman/listinfo/nsrca-discussion</a> <br>
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