My Ozark 17 SMT transceiver kit from 4SQRP arrived. It is tiny.
8P6JD Rod in Barbados
I worked 8P6JD Rod in Barbados on 20M CW with my HFPacker Amp.
I worked ES1QD
Vello in Tallinn, Estonia on 14.02691 at
Thu Apr 22 0422z and got a 579 RST with 50W CW on my new HFpacker Amp!
I joined the Flying Pigs QRp club and I am FP#844 and I got a score of 3
in their monthly contest, though I did hear N3ESE but didn't make
contact. I used my HFPacker amp for the first time since I got it
working - last week I used it on 20M PSK31 but blew the mosfets with
From: Jim Sheldon <email@example.com>
Subject: [QRP-L] Run For The Bacon - 2 hour sprint, sponsored by the
Flying Pigs QRP Club International
Date: Sun, 18 Apr 2004 19:09:25 -0500
The Monthly FPQRP "Run For The Bacon" sprint starts in less than an
hour. The issuing of FPQRP numbers is closed for the night,
with Leigh, WA5ZNU being the last one to squeak in under the wire. We
have 19 new piggies since yesterday morning, and if they all
enter the sprint, the magic "50" bonus may just become a reality for
some. GL and see all of you that participate in the RFTB, I
hope - (The propagation gods willing)!
Jim Sheldon, W0EB
FPQRP Membership Chairman
HFPacker Amplifier (QRO?)
50-55W out from 2.5-3W in on 40m on my HFPacker amp...I fixed a place
where a hex standoff had shorted to the MOSFET board top with a nylon
washer and replaced both MOSFETs (43 cents each in qty 10 at Jameco will
call), and it works! Probably I need to do some filter board work on
20M and higher...
gave me a 579 on my PSK-20 at 40W or so on 14.070.
NEED TO QSL.
My HFPack QRP amp is fully assembled, and the power supply generates
24.0 volts but when I provide the power to the MOSFET amp board it
squeals and the regulator gets hot. Sounds like it is shorted
Exploratorium Argon discharge plasma
At the Exploratorium, this Argon discharge plasma tube is driven by a
three stage tube exciter and amplifier. The SWR was 3:1 on 13MHz, it
looks like from the meters...
Here are the output waveforms of Rich KD6WYK's amplifier with my filter board.
Both are with the 40M filter with 7.0 MHz input and 50v/cm on a 20MHz digital scope.
The first picture is with ~1W drive and the second with ~3W drive.
The measured output power was about 12W and about 29W.
Homebrew your own crystal frequency
Homebrew your own crystal frequency
QRA (Maidenhead Grid) in EMACS Lisp
(defun qra (latitude longitude)
(setq longitude (+ longitude 180.0))
(setq latitude (+ latitude 90.0))
(+ 65 (floor longitude 20.0))
(+ 65 (floor latitude 10.0))
(+ 48 (floor (* 10 (- (/ longitude 20.0) (floor longitude 20.0)))))
(+ 48 (floor (* 10 (- (/ latitude 10.0) (floor latitude 10.0)))))
(+ 32 65 (floor (* 24 (- (/ longitude 2.0) (floor longitude 2.0)))))
(+ 32 65 (floor (* 24 (- latitude (floor latitude)))))))
(qra 37.428833 -122.114667)
QRPProject.de End-Fed 1/2 wave end-fed tuner
This is my new multiband tuner for end-fed wire from QRPProject.de
, for use with the
AMQrp end-fed L on 40m.
Here is my GlowBug 40
kit and a
piece of Aluminum I bought to make the top of the chassis. For the
bottom Dwight KG4HSY recommends wood, and Lucite for the sides:
The dimensions of the piece of metal before I had it bent was 13" X 4 3/8". The metal is bent 90 degrees, 4 1/2" from each end. This forms two sides 4 1/2" high. The cabinet is 4" wide across the top and of course 4 3/8" from front to back. The metal sides over a 4" X 4" X 3/4" block of wood which forms the base of the transmitter. The metal is 3/8" deeper than the wood base so this forms an overhang over the front piece of Lucite. I used 1/4" Lucite. If you use 1/4" Lucite you will have to countersink the plastic nut on the key jack. You could leave the nut off and you wouldn't have to do any countersinking.
LM1458 vs LM833 op amp in PSK-20
I tried upgrading the LM1458 op amp used as the audio amplifier in my PSK-20 to an LM833, as recommended by N4WFS in his eHam.net review. Here are the before and after specrum images. Of course, time passed, QSB happens, and stations change. But I didn't note a big difference. Maybe it will help with improving the blocking dynamic range when strong signals are present.
Roller inductor for FM diplexer.
On the way out, I saw that they had used the burned-out roller inductor as a doorstop.
Tonight's PAARa meeting's speakers
are the Bay Area chief engineers for ClearChannel, Chuck Waltman N0CW
and David Williams KD6QPR. Here is
the talk overview.
This is an AM broadcast final transistor that produces about 400
Watts. Modern AM broadcast transmitters are digitally driven with 96,
128, or 256 finals, all run at eith 0 or 100% except 6 that are run at
1/2, 1/4, 1/8 etc. To round out the sine wave. This one has 8
A transmitter with these finals runs at 92% efficiency.