Double Twin Triode Regeneration Radio
I am glad in hosting this design in my website. Please contact the author for any question.
You also will find :
·
The original post
·
A datasheet of 6SN7 (in English) can be found here. Specifications
can be found in a PDF datasheet pointed by this page, in German.
- A datasheet of 6SL7 (in English) can be found here.
- Comments
from Dr. Arnaldo Coro here on
alternative valves for the same design and on the design itself.
- Comments
about the 300 pF capacitor
- Comments about the 30 Hy choke
Congratulations to the author.
73 Dimitri F4DYT
The original post
From: Scot Armstrong [mailto:scota4570@yahoo.com] Here it is. Please feel
free to put it on a site that everyone can get to.
This set is the best I have
some up with so far. That is why I have chosen to share it. It is
the product of several years of listening to all of you. I put into
place the lessons from this board and it's members. If you keep the
leads very short, the layout good, and optimize it, it is a very strong
performer. There is nothing revolutionary in it's design. Just my
best construction techniques and keeping it neat and simple. Have fun, Scot Armstrong |
Alternative valves for the design
From:
owner-glowbugs@piobaire.mines.uidaho.edu [mailto:owner-glowbugs@piobaire.mines.uidaho.edu]On
Behalf Of Prof.Arnaldo
Coro Antich Sent: vendredi 2 janvier 2004 20:20 To: Scot
Armstrong Cc:
glowbugs@piobaire.mines.uidaho.edu Subject: GB>
Re: Scot's Regen Schematic a small mistake Dear amigos
GLOWBUGS There is a little
mistake in the schematic of the Scot Armstrong nice receiver... The input
capacitor must go only to the center of the potentiometer, and not to ground
too... Just erase the
line that sends the signal from the antenna to ground !!! [Editor's comment: done in this Web page] BTW, it would be
nice to learn about amigo Scot's coil, and how he made it( number of turns,
wire diameter and diameter of coil... May want to test
the circuit also with my favorite 6AK5-5654-6ZHE1P tube, using another one
triode connected as the grounded grid RF amplifier stage... ( Got plenty of
the 6ZHE1P Russian tubes here !!! ) 73 and DX Seasons Greetings
to all Arnie CO2KK |
More alternative valves and
comments on design choices
From:
owner-glowbugs@piobaire.mines.uidaho.edu [mailto:owner-glowbugs@piobaire.mines.uidaho.edu]On
Behalf Of Prof.Arnaldo
Coro Antich Sent: vendredi 2 janvier 2004 20:09 To: Scot
Armstrong Cc:
glowbugs@piobaire.mines.uidaho.edu Subject: GB>
Re: Scot's Regen Schematic Dear amigo: Regarding Scot's
Regen Schematic just received here !!! You may want to
try ( for more audio output to headphones and also quite enough for a
loudspeaker ) to use an ECL82 triode-pentode audio amplifier tube, that was
very popular among European radio receiver manufacturers of the late fifties
and early sixties, before transistors took over the stage. Also, you may
want to test the European ECC85 noval 9 pin miniature dual triode for the RF
amplifier and regenerative detector stage instead of the 6SN7. Your values of 40
pf and 10 megs for the grid of the regenerative detector are ABSOLUTELY RIGHT
for best possible results from a regenerative vacuum tube detector !!! I use here 50 pF
and 8,2 megs, as those values are easily found from recycled vacuum tube TV
sets that are plentiful locally . Another fact that
people often forget is to build the regenerative detector stage as if you were
building a battleship !!! Have you seen the ZL2JJ regenerative receiver ??? I have all the
information about it, and can send them to you, including the diagrams and
photos of what I believe is the best ever regenerative receiver ever built ! ~73 and DX Your friend in
Havana Arnie Coro CO2KK |
Comments about the 300 pF capacitor-----Original
Message----- OK amigo ! Understand you keep the
300 pf to ground as a fixed capacitance, and that you change the voltage
provided to the detector very smoothly... Have you ever tried a
HELIPOT tm , helically wound potentiometer ( 10 turns maybe ) for the
regeneration control ??? Will test an exact
replica of your circuit tomorrow and then will comment about the results !!! 73 and DX YOur friend in Havana Arnie Coro CO2KK -----
Original Message -----
Sent: Friday, January 02,
2004 8:19 PM Subject: Re: Amended
Schematic No mistake, in the version I
am running right now the double stack pot takes care of fine regen
control. I did make the suggestion that one cold use a small cap
paralled across the first 300pf for the same purpose. Scot DEAR AMIGO : WELL... WELL, STILL
ANOTHER GLITCH !!! If my eyes are good there
is a little mistake still there... The 300 pF
""throttle"" regeneration control capacitor should be a
variable, not a fixed one !!! It would only take you a
minute to draw the line across the two plates to indicate that this is a
variable and not a fixed capacitor !!! 73 and DX YOur friend in Havana Arnie Coro CO2KK |
Comments about the 30 Hy choke-----Original
Message----- Hello, Well technically speaking I
didn't have one either. I do have about fifty pounds of vertical output
transformers. So I used the one with the most Henries I could find on
the top of the pile. It was higher than my meter could measure, that
made it over 20. It seemed to be quite a bit over 20 so, I guessed at 30.
I don't think you would see such difference between a 10, 20 or 30H
choke. The one good thing about a choke is that you could make it
resonate for CW reception. With a 20H choke put about a .002 cap on the
side of the choke that is away from the HT and ground the other side of the
cap. A simple audio filter. Again try several values
to se what works best. If you don't have a choke, I see no reason a guy
could not fiddle around with a resistor switch box to find a resistor that
worked. For that matter a transformer could also be used. Connect
one side to the next in the way that gives the highest inductance. For
gosh sakes don't let the lack of a 30H choke stand in the way! Scot Armstrong
On Fri, 2
Jan 2004 dzabcik@texas.net wrote: |
