[HBR] HBR Chassis Kit continued or not : )

[Martin Marris]

Hi Bill,

The answer to your question about my primitive receiver is answered at great
length in this thread on eHam:
http://www.eham.net/ehamforum/smf/index.php/topic,90273.0.html.

The short answer is that for a receiver that relies on early generation
FETs, and is regenerative to boot, performance is surprisingly good.
Certainly good enough for use in QSOs, or at least I hope so (I'm not on the
air yet). Above all, it is very sensitive. Admittedly, it is as wide as a
barn door but you can't really expect stellar selectivity from a regen.

In the past couple of years I have logged several hundred "SWL" QSOs from
all over the world on 10, 15, 20, 40 and 80m on this little receiver. I
can't wait to use it in a two-way QSO!

In a general sense however, I cannot answer your question. I am a "new ham"
(licensed three years ago but with very little spare time) and this is my
*only* receiver: I have not been "spoiled" by a more elaborate superhet or
by commercial gear. My goal is to get on the air with an entirely homebrew
station, vintage 1968. (I have also built the companion three-tube
transmitter and my project is described here:
http://www.eham.net/ehamforum/smf/index.php/topic,97719.0.html).

The biggest puzzle with the receiver was that, if you built it exactly as
described in the ARRL project, it worked well on 80m and 40m but was a bust
on the other bands (it either failed to oscillate; or when it did, it
"motorboarded" and overloaded badly enough to be unusable).

This was eventually fixed by varying the value of C9, band by band. I don't
really understand why the original design allegedly worked fine. My exact
copy of it did not -- but regen receivers are tricky.

I am so pleased with this little receiver that I have (possibly
over-ambitious) plans to build a second one, with the same circuit but using
slightly larger, 6-prong Amphenol coil forms (instead of the 1", 5-prong
Millen ones in the original). This would allow me to wire C9 inside the coil
form itself and eliminate some awkward fiddling around every time the band
is changed. As of now, I'm using the receiver pretty much as a monoband 40m
set and plan to hang out on that band exclusively for the first few months
after I get on the air this summer.

For what it's worth, I get the impression that with receivers, it's the care
taken in construction and the quality of the components that accounst for at
least 50 percent of the results. A very simple regenerative set probably
outperforms a multi-tube superhet that's just been thrown together.

73 de Martin, KB1WSY


-----Original Message-----
From: HBR [mailto:hbr-bounces at mailman.qth.net] On Behalf Of William Wood
Sent: Monday, April 20, 2015 10:33
To: HBR Receiver List
Subject: Re: [HBR] HBR Chassis Kit continued or not : )

Hey, I know the subject I'm asking for is OT, but that is quite the receiver
there : )  A LOT of work went into a three transistor receiver.  Could you
give me a report on it's abilities???  I'm not thinking of building it, but
would love to hear it works like a charm, or better then what one would hope
for a three transistor receiver : )

Must have been worth something for all the work you put into it : )
73 fer now
Bill  KE9XQ



On Apr 20, 2015, at 3:28 AM, Martin Marris <mmarris at notecraft.com> wrote:

>>> Had anyone used the "Omni Chassis Kit" from LMB/Heeger?<<
> 
> 
> 
> Yes. Web links to project description and photos are listed below; the 
> Omni Chassis is pictured in Chapter Two. For best viewing, click on 
> the first photo then click the Full Screen icon at top right. The only 
> objection I would have to the otherwise excellent Omni Chassis kits is 
> that the metal is relatively thin; for an HBR project it might not be 
> stiff enough. IIRC the thickness is listed on the LMB website, for each
size of chassis.
> 
> 
> 
> Chaper One, "Project Description and Components":
> http://tinyurl.com/ktylgzn.
> 
> 
> 
> Chaper Two, "Metalwork": http://tinyurl.com/khckgdu.
> 
 
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