Hi, Dave

Does the Dovetron have a USB/LSB switch,
or can it be switched remotely? (My HRO-50 is rack mounted,
so no easy access through the top of the receiver).
Also, does it provide a good AGC system?
Audio derived AGC? Can you point me to a schematic?

Thanks,
Ed

"Edward Knobloch" wrote in message

I'm thinking of adding a product detector to my HRO-50.
I see that Dovetron used to make an adapter that plugged into
the NBFM socket. Does anyone have any experience
with the Dovetron unit, and can anyone point me
to a schematic? BAMA and the ManualMan came up empty.

Thanks,
Ed Knobloch

Dave Stadt wrote:
I have one in a Collins 75A2. It's pretty remarkable.

I found the article and will be able to scan it on Monday and send to those
interested. While at it, I will scan the companion transmitter. It uses a
6DQ6 tube, which is plentiful and cheap.

If interested, drop me an e-mail.

73, Colin K7FM

How about a regenerative superhet? Maybe use a triode/pentode tube as
a converter in front of a regen detector running at 2 or 3 MHz. If you
wanted full coverage the L.O. of the converter would be an LC
oscillator, but for ham-band only you could use a crystal oscillator
for more stability. Might be something like

6EA8 converter (triode oscillator, pentode mixer)
6EA8 detector & first audio (pentode detector w/ screen voltage
control, triode first audio)
6AQ5 or 6CU5 audio out (6CU5 will give more audio at lower B+, 6AQ5
more at higher B+)
OB2 regulator for the 6EA8s

73,
Mike, KK6GM

The regenerative superhet described by Mike is a good idea. it is known as
the "super gainer" and was pioneered by Frank Jones. They are described in
the 1938 Radio Handbook. The converter in front of the regen receiver
substantially reduces radiation by the receiver and also eliminates the
effect of a swaying antenna. By setting the fixed if between two amateur
bands, both bands can be covered with one oscillator coil. The drawback is
an increase in parts count .

For some, simplicity becomes elegance. There is nothing like honing your
skills during a gusty evening, where the open oscillator coil changes pitch
with each puff of wind and your movement around the room. For those, a
digitally locked oscillator is heresy.

Colin K7FM

"Edward Knobloch" wrote in message
news:jKiyf.444$Bn4.146@trndny08...
Hi, Dave

Does the Dovetron have a USB/LSB switch,
or can it be switched remotely? (My HRO-50 is rack mounted,
so no easy access through the top of the receiver).
Also, does it provide a good AGC system?
Audio derived AGC? Can you point me to a schematic?

Thanks,
Ed

Extensive AGC mods are part of the change and work very well. USB and LSB
is selected by the variable BFO so no real change there. I can send you
the 75A2/3 instruction and schematic if you wish. Looks like the plug-in is
the same for Collins, HRO and NC-183D. You would be on your own for the
actual radio mods which could be extensive. The plug-in socket gets rewired
as well as numerous other mods.

Well, copies made today, so I will now scan those. Progress is sometimes
slow. Colin K7FM

Very smooth regen control. Except for the plug-in coils requirement...

Though I realize the feedback windings would be problematic to reproduce...I
listened to many 40M SSB QSOs on Saturday mornings with the Knight Space
Spanner.


Perhaps LA5KI would consent to doing some measurements on his coils...

73, Steve, K9DCI

http://www.qsl.net/kb7rgg/allied/sch...acespanner.gif
http://www.qsl.net/kb7rgg/allied/pro...dio/83y209.txt

Pix he
http://www.qsl.net/la5ki/org/kn/spsp.htm
It is called a Super-regen here, but I don't think it was.



"Dale Parfitt" wrote in message
news:Bdeyf.1445$he.1382@trnddc03...
Hi Group, I am entertaining building anohter regen. My first attempt,
although pretty, was a mediocre performer- using a 3 section compactron
tube.
http://parelectronics.com/pics/regen2.jpg
Design goals a
1. plug in coils for band changing MW-20 MHz or so.
2. speaker level audio
3. smooth regen
4. prefer miniature tubes to octal.

Anyone care to post their favorite schematic/ links/ thoughts?

Tnx,

Dale W4OP

I now have the 2 tube regen receiver from "How to Become a RadioAmateur"
scanned and ready to send. Also scanned the companion transmitter. Both
are in .pdf files. Each is about 5 mb. I am just not efficient at
compressing files without losing quality. I will attempt to send them out
to those that have requested. If it fails, we can keep trying.

73, Colin K7FM

On 1/18/06 8:31 AM, in article
et, "COLIN LAMB"
wrote:

I now have the 2 tube regen receiver from "How to Become a RadioAmateur"
scanned and ready to send. Also scanned the companion transmitter. Both
are in .pdf files. Each is about 5 mb. I am just not efficient at
compressing files without losing quality. I will attempt to send them out
to those that have requested. If it fails, we can keep trying.

73, Colin K7FM



Could you just upload the files to a.b.s.e.? Everyone who wants it can
download it.

Don

I compose in Word then paste. This part didn't get pasted:

I had the Knight-Kit Space Spanner and used to listen to some SSB regulars
on 40 M every Saturday.

Very smooth regen control. Except for the plug-in coils requirement...

Though I realize the feedback windings would be problematic to
reproduce...I
listened to many 40M SSB QSOs on Saturday mornings with the Knight Space
Spanner.


Perhaps LA5KI would consent to doing some measurements on his coils...

73, Steve, K9DCI

http://www.qsl.net/kb7rgg/allied/sch...acespanner.gif
http://www.qsl.net/kb7rgg/allied/pro...dio/83y209.txt

Pix he
http://www.qsl.net/la5ki/org/kn/spsp.htm
It is called a Super-regen here, but I don't think it was.



"Dale Parfitt" wrote in message
news:Bdeyf.1445$he.1382@trnddc03...
Hi Group, I am entertaining building anohter regen. My first attempt,
although pretty, was a mediocre performer- using a 3 section compactron
tube.
http://parelectronics.com/pics/regen2.jpg
Design goals a
1. plug in coils for band changing MW-20 MHz or so.
2. speaker level audio
3. smooth regen
4. prefer miniature tubes to octal.

Anyone care to post their favorite schematic/ links/ thoughts?

Tnx,

Dale W4OP