Italian Experimental Station in the Good Old Days... And Today!

Today (he tells me it is 50 years later!) my friend Gianfranco is on the air as I0ZY.
Transmitter back then was homebrew except for a Geloso VFO purchased for 7000 lira (11 dollars at the time). Tubes were 6J5's and 6V6's. It ran AM. Two 807's in the final with 600 volts on the plates. Two 6L6's running AB2 as the modulator. His mic was salvaged from an old wire recorder. Except for the VFO, everything was from WWII surplus.
On the receive side, he had an HRO 5 by National that he picked pretty much in the same flea market area that we visit today. It was in such bad shape that they gave it to him for free! With a lot of patience and persistence, he was able to get it to work on 20 meters. Gianfranco clearly had The Knack!

And he still does! He now has a wonderful company (SPE) that manufactures in Italy some very advanced linear amplifiers. He is the designer and creator of the Expert 1K-FA. Check out this video on his company and his product:



Here is the link to the site for the Expert 1K-FA:
http://www.radio-ham.eu/Expert1K-FA.htm

SSSSSSolder SSSSSSSmoke's SSSSSSS problem

In SolderSmoke 109, I did a little experiment. Normally I do some audio processing using Audacity's Equalization option. In all of the recent episodes, I have been using an equalization curve similar to the one shown above. I drop off the low frequencies (to get rid of the Popping P sounds) and I put a notch at around 3500 Hz in an effort to get rid of the problematic SSS sounds. I had my doubts about the effectiveness of all this. Partly in an effort to save time, SolderSmoke 109 I dispensed with the processing. I immediately got a couple of e-mailed signal reports saying that the nasty SSSS sound was back.
I really can't hear it on my computer. This may be related to different sound cards. And some high frequency hearing loss that I picked up on the rifle range may be involved.
If you can, please compare the sound quality in SS108 with that of SS109, and let me know what you think.
Dean, WA6P, and Bill W7AAZ, going to send me a passive audio filter that we hope will help.
On a similar note (!), I am looking for a circuit for a simple audio signal processor for use with my DSB rigs. I need something simple that will provide both clipping (probably via the standard two diode arrangement) AND audio frequency selection. The ability to put upper and lower limits on the audio frequencies is important in DSB rigs, because they lack the crystal filters that do most of this work in SSB transmitters.

SolderSmoke -- The Book. Table of Contents

As promised in SolderSmoke 109, here is the Table of Contents for the new SolderSmoke book.

CONTENTS

Preface

Chapter 1 Electrically Inclined – Tales of an Electromagnetic Youth
Electrons and Electricity
Radio Waves
Some Basic Equations
Einstein in the Transformer
Semiconductors

Chapter 2 Off-the-Air—Amateur Radio Goes Into Hibernation
Junctions and Diodes

Chapter 3 Tropical Rebirth—Ham Radio in the Dominican Republic
The Lowly Capacitor
Resonance and Oscillation
Series and Parallel Tuned Circuits

Chapter 4 Boatanchors in Virginia—Back in the U.S.A.
Transistor Amplifiers
Mixers
Modulation: AM, DSB, SSB

Chapter 5 Mid-Atlantic Outpost—Amateur Radio from the Azores
Balanced Modulators

Chapter 6 Urban Radio—Solder Smoke in Central London
Amplifier Loads

Chapter 7 Rome—Secret Radio in the Eternal City
Feedback in Amplifiers

Chapter 8 Conclusions—A Brotherhood Without Borders

Acknowledgements

Index

To order: http://www.lulu.com/content/paperback-book/soldersmoke/6743576

SolderSmoke Podcast #109

http://www.soldersmoke.com

June 7, 2009

Violin gig in Rotterdam
June 2 Parade in Rome
Why do we use Rl=Vcc^2/2Po for Class C amps?
     NA5N article, EMRFD, SSDRA, LTSpice
Radio Signals from Jupiter and Io (on 17 meters)
VK2ZAY's X-Rays
Jeff Damm, WA7MLH:  Homebrew Hero
Tim Walford's Constructor's Club:
     Floor Polish as PCB Laquer
     Numbers Stations (very timely!)
SolderSmoke -- The Book: Very rapid delivery, even to UK
MAILBAG

The Look of a True Radio Homebrewer

Jeff Damm, WA7MLH, is one of our gurus, a high priest of The Knack. I visit his excellent site from time to time, just on the off chance that he will have posted something new. This morning I was rewarded with this picture from 1988 -- I think it somehow captures the spirit of the true radio homebrewer. Check out all the homebrew gear. Note the copy of SSDRA on the operating table. Jeff assisted with the construction of many of the projects in that book. He helped free us from the tyranny of excessive neatness and right angles, and let us know that ugly circuit construction works just as well.
Here's Jeff's FB site: http://www.neoanderthal.com/wa7mlh1.html