Daily GLOWBUGS
Digest: V1 #129
via AB4EL Web Digests @ SunSITE
Purpose: building and operating vacuum tube-based QRP rigs
Subject: glowbugs V1 #129
glowbugs Monday, October 6 1997 Volume 01 : Number 129
Date: Sun, 5 Oct 1997 14:00:43 +0000
From: janax@mail.li.icl.se
Subject: Regenerative RX article available
... on my web at http://www.algonet.se/~janax/glowbug.htm
It's a scan and retype of an article in the 1950 ARRL handbook and is
a regenerative receiver using a 6SN7 twin triode. It differs a little
from ordinary designs in having a potentiometer varying the detector
plate voltage as regeneration control.
Enjoy!
Jan, SM5GNN
Date: Sun, 5 Oct 1997 16:53:16 +0000
From: Sandy W5TVW <ebjr@worldnet.att.net>
Subject: "BA" gathering on CW...
Hello Fellow CW operators!
Summertime brought about a shift to 40 meters to 7050 khz., then
some of us
wandered around and used 7060 khz. Operations were plagued with Mexican SSB
QRM and also lots of "digitalis" working their way down the band, closer and
closer
to the 7025 "Extra" barrier. Anyway, 40 has become a nightmare at night for the
casual operator and ragchewer.
80 meters has again become quiet enough to use again. Soon we will be
going off Daylight time, which will allow more darkness earlier, enhancing
80 meters! Drop by evenings at 0100, 0200, 0300Z on 3579.5 and blast forth
with a "CQ BA".
I hope we will be able to get the group together again this
winter.....soon.
Dust off those old rigs and get them emitting some RF!
73,
E. V. Sandy Blaize, W5TVW
"Boat Anchors collected, restored, repaired, traded and used!"
417 Ridgewood Drive
Metairie, LA., 70001
Date: Sun, 5 Oct 1997 13:58:38 -0600 (MDT)
From: Terry Dobler KJ7F <kj7f@micron.net>
Subject: More October Regen project
Gang,
In my regen I am currently using a grid leak resistor from
the grid to ground. In other circuits the resistor is in series
with the tank to grid circuit. I know that the both work but
was wondering what the advantages of each type, if any, would
be? Any one have any input?
Terry KJ7F
kj7f@micron.net (Boise, Idaho) http://netnow.micron.net/~kj7f
Date: Sun, 5 Oct 1997 22:00:42 +0000
From: Sandy W5TVW <ebjr@worldnet.att.net>
Subject: FS: Pull-out 4CX1500B
I have a 4CX1500B "pull out" that I'm fairly certain still has some
life in
it. I can not guarantee it but if someone wants to take a chance on it,
I'll sell if for $30 shipped or maybe we can trade something.
I'm presently looking for a resistor cabinet or two, like the old
IRC metal resistor
cabinet or a couple of the smaller Ohmite "Little Devils" cabinets.
What say ye, collectors of BA junque?
73,
E. V. Sandy Blaize, W5TVW
"Boat Anchors collected, restored, repaired, traded and used!"
417 Ridgewood Drive
Metairie, LA., 70001
Date: Mon, 6 Oct 1997 00:43:21 -0400 (EDT)
From: EricNess@aol.com
Subject: The Ferrite Bead Regen
In the spirit of Regen Month, I would like to describe a neat little brocast
band regen I built using a very modern ferrite bead and some good old
techniques.
For many years I have worked in the computer industry (for a place described
by Forrest Gump as "Some Fruit Company") and occationally have had access to
discarded prototypes and parts. You don't find much good for RF work in that
stuff but I did collect a number of ferrite beads from old monitor and SCSI
cables.
This kind of ferrite bead is designed to create enough inductance on the
shield of a cable to eliminate the high frequency component from the currents
flowing on the shield. Since there is only one turn in this kind of
inductor, the mu of the ferrite has be be large, typically 950. In other
words, the inductance per turn is extremely large.
I decided to see if one of these ferrites could be used in a regen style
receiver and had some very pleasing results. I chose to build a BCB receiver
since they are very easy to test. I found that it only took SIX turns to
achieve the correct inductance to tune the broadcast band with a 365 pF cap.
The feed back loop was a single wire through the core as was the antenna
connection.
I must confess that I used a FET in the receiver I built. Feedback control
was by varing the drain Voltage and a single 9 Volt battery was the power
source. I found that I could seperate the half Megawatt stations from the
weaker ones just fine. In general, the little ferrite regen was an excellent
replacement for a standard superhet receiver, at least as local reception
goes. As a matter of fact, I used this simple receiver as my emergency
receiver during the power outages last season as my other BCB receivers
require AC power.
In the spirit of the glowbugs list, I would like to build a version of my
ferrite receiver using one of those hearing aid tubes. I have one or two of
them in the junk box, if I could only find them. I could probably fit it
into one of those metal mint boxes if I could find one of those mica tuning
condensers.
If anyone would like more details about the ferrite receiver, Please let me
know and I will elaborate.
73, Eric WD6DGX
Date: Mon, 6 Oct 1997 00:20:37 -0500 (EST)
From: "Roberta J. Barmore" <rbarmore@indy.net>
Subject: On the air!
Hi!
Restrung part of the G5RV (pretzel installation) and finally worked up
nerve to put the ol' "Jones" 6L6 job back on the air--worked up to it with
a little SS British kit on 80 (reported chirpy but it's just my old
low-current power supply--not bad for a QSL-size xcvr and at least it's
got no BJTs).
Warmed up the Drake 2-B and checked out 7050-7060 and parts nearby from
10-12p EST but didn't hear any familiar calls. Worked NZ5M in Lubbock,
TX (977 miles, 599 both ways, the DXers will *pse* stop snickering) around
11pm EST and am pleased to report he was using a "big old Navy rcvr," had
a 2-C on the desk, and knew what a 6L6 was! :)
If I don't get too sleepy, I'll try to be on 40 or 80 this week. 80's
iffy, it sort of gets into my neighbor's TV and he's a ham.... ;)
73,
--Bobbi
Date: Mon, 6 Oct 1997 09:27:24 -0400 (EDT)
From: rdkeys@csemail.cropsci.ncsu.edu
Subject: Re: Hartley Weirdness --- trying to get more feedback.
>
> Bob,
> Just a thought..............what about the old makeshift neutralizing cap
> type trick? An insulated wire or small plate off the grid spaced up along the
> side of the tube?
>
> Eric
>
Gee, never tried that. If you could get enough capacity out of it to
cause oscillation, there is no logical reason why it would not work.
Some rigs used strips of aluminum. That might have enough capacity.
The wire would only have a couple of pf capacity, if memory serve me
correctly.
Bob
End of glowbugs V1 #129
***********************
Created by Steve Modena, AB4EL
Comments and suggestions to modena@SunSITE.unc.edu