WA5ZNU: 04/01/2004 - 05/01/2004

Ozark 17

My Ozark 17 SMT transceiver kit from 4SQRP arrived. It is tiny.
- posted by Leigh @ 05:28 z 0 comments

8P6JD Rod in Barbados
I worked 8P6JD Rod in Barbados on 20M CW with my HFPacker Amp.
- posted by Leigh @ 22:15 z 1 comments

ES1QD
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!
- posted by Leigh @ 04:42 z 0 comments

FPQRP
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 feedback.

From: Jim Sheldon <w0eb@cox.net>

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)!

73/72/OO,

Jim Sheldon, W0EB

FPQRP Membership Chairman

- posted by Leigh @ 18:48 z 0 comments

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...
- posted by Leigh @ 00:17 z 0 comments

KQ6QB
KQ6QB gave me a 579 on my PSK-20 at 40W or so on 14.070. QSO 0457z NEED TO QSL.
- posted by Leigh @ 16:50 z

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 somewhere.
- posted by Leigh @ 01:12 z 0 comments

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...
- posted by Leigh @ 21:30 z 0 comments

- posted by Leigh @ 21:28 z 0 comments

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.
- posted by Leigh @ 20:34 z 0 comments

Homebrew your own crystal frequency
Homebrew your own crystal frequency
- posted by Leigh @ 05:01 z 0 comments

QRA (Maidenhead Grid) in EMACS Lisp
QRA

(defun qra (latitude longitude) 
  (setq longitude (+ longitude 180.0))
  (setq latitude (+ latitude 90.0))
  (format
   "%c%c%c%c%c%c"
   (+ 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) 

; CM87wk

- posted by Leigh @ 01:50 z 0 comments

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.
- posted by Leigh @ 01:17 z 0 comments

GlowBug 40

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.

- posted by Leigh @ 01:09 z 1 comments

LM1458 vs LM833 op amp in PSK-20

Before
After

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.

- posted by Leigh @ 04:18 z 0 comments

Roller inductor for FM diplexer.

On the way out, I saw that they had used the burned-out roller inductor as a doorstop.

- posted by Leigh @ 05:26 z 0 comments

More tubes and transmission line. The tube is for an FM transmitter.
- posted by Leigh @ 05:24 z 0 comments

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 transistors.

A transmitter with these finals runs at 92% efficiency.

- posted by Leigh @ 04:58 z 0 comments

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