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Saturday, February 7, 2009

AA1TJ and AA1MY MAKE QRP HISTORY

I was feeling smug about my version of the ET-1/FETer single FET transceiver. I built the transmit portion of the rig this morning, and it fired right up, producing a nice clean CW signal. But then news came in of the historic 100 mile QSO between Michael, AA1TJ, and Seab, AA1MY. Michael was using his new Mikums rig, an 80 meter transceiver built around one tunnel diode. My FET rig seems like a QRO appliance in comparison to the Mikums. Michael's diode rig was putting out 160 micro watts. Yes, 160 uW. Congratulations to Mike and Seab. I'm sure Mike would not mind my sharing his e-mail on this subject (see below). Reading it, you can just feel the excitement that came from this historic contact. I'm sure tunnel diode inventor Leo Esaki (pictured above) would be pleased.
Be sure to check out Michael's description of the rig:
http://mjrainey.googlepages.com/mikums
Also, don't miss the pages on Reginald Fessenden:
http://www.newsm.org/Wireless/Fessenden/Fessenden.html

Friends,
Seab, AA1MY sent me a message just over an hour ago saying that he suddenly began hearing my Mikums transceiver running as a beacon! Seab lives in Bethel, Maine, an air distance of exactly 100miles/160km from my QTH. A few hours earlier I'd measured Mikums' output power at 169uW (yes, microWatts!).
I was at the computer when his message appeared so I quickly called him on the telephone. He said that he'd been monitoring while he was busy with some paperwork. He'd just returned from fetching a load of firewood and all of a sudden there I was! He put the phone near his loudspeaker and I just about fell over! I was weak, but perfectly readable.
Then I practically hung-up on the poor fellow in order to race down to my shack in order to try for a QSO. I heard him clear as a bell at a power of 40w (I reported 459, but I ought to have sent 559). He confirmed my report and then dropped down to 4w. Although weak, I easily copied his 429 report to me. I gave him a 219, which he confirmed.
Oh boy...it's done. We made a skywave QSO using a one-tunnel diode transceiver. I'm practically giddy here :o)
Many thanks to Jim, W1PID, who has patiently listened for several days. In fact, Jim has copied my CQ and callsign several times before my signal evaporated on a breeze of QSB. In return, I copied Jim's Small Wonders Labs DSW at 2w on Mikums with no problem the other day. Again, many thanks, OM. The next time we meet, I'm buying, okay?
Again, way to go Seab; that's one small step for man....naw, more like one more exciting and thoughly useless (ain't it great!) milestone in the history of QRP :o)
73/72's all around,
Mike, AA1TJ

Thursday, February 5, 2009

St. Elmo's Fire and Lightning Brushes

I guess I am and AMer at heart. As a kid I used to listen to the AM QSOs on 75 meters in the Northeast. I still occasionally take a look at the AM Window website and follow the chatter from afar. This is another corner of the hobby where guys still melt solder and study schematics.

One of the many interesting things found via the AM Window is an on-line archive of the AM Press/Exchange newsletter. There are some very good articles in there. Issue #114 has a good one by George, W2WLR. It's about lightning and ways to prevent strikes. What I like about the article is the very practical, hands-on approach. George describes how one intrepid enthusiast put an amp meter between a radio tower and ground and watched the currents generated by a nearby storm (don't try this at home!). The article discusses how brushes on the ends of lightning rods help bleed off charge. You can see some charge bleeding off the masts of the ship depicted above.

After reading his article, I went to work. In an idle moment, I looked out the window across Rome's Via Veneto and saw on one of the hotels some lightning rods tipped not quite with brushes, but with multiple spikes. Go St. Elmo!

Wednesday, February 4, 2009

Humber College Homebrew Space Station Contact? Not really

I wasn't going to mention this, but since we were talking about Grote Reber, I sort of feel obliged to raise this subject. The techno-blogosphere is filled this morning with the story of four Humber College (Toronto) seniors who supposedly contacted the International Space Station with homebrew gear. See: http://www.humber.ca/stories/first_contact.htm Wow, pretty good, eh? Well, not so fast SolderSmoke fans. Turns out you have to read the fine print. They did it with a radio system that they "designed and built themselves." I looked at the slide show and their operating table was covered with expensive commercial gear. Sure enough, when I checked their blog, I found this:

Today, Mr. Rector, Paul, and I went out to
Radioworld and purchased a transceiver. After much research, we decided to go with the ICOM Ic-V8000. For the cost, it has exactly what we need. On Friday, we're going to be integrating it into our setup, and doing all the necessary testing.

This contact was no big deal really. When I was talking to Norm Thagard on MIR station back in the 20th century, there was one 13 year-old kid in South Africa who pulled off the same feat.
See: http://www.gadgeteer.us/MIR18.HTM If they had actually built the radios themselves it would have been a bit more noteworthy. Looks like this one had more PR smoke than solder smoke.

Tuesday, February 3, 2009

RADIO PIONEER: GROTE REBER

Grote Reber has always been a hero of mine. Above you can see the dish that he built in his backyard to conduct radio astronomy in the 1930's.
Read more about OM Grote here: http://www.nrao.edu/whatisra/hist_reber.shtml

Sunday, February 1, 2009

SolderSmoke NUMBER 100

http://www.soldersmoke.com

SPECIAL CENTENARY EDITION
A look back to the beginning
Rome Travelogue: Palatine Hill
Fixing my old freq counter: Trials and Tribulations
Empire of the Air:
More great history, but more tech faux pas
"The radio art"
An historical precedent for our GONG
Lake DeForest?
A. Frederick Collins
Understanding Beta Independence
Understanding Feedback and Distortion
SPRAT 137: Minimalist Radio:
The FETer/ET-1: "Haiku from Solder"
Regens: Not for the faint of heart
NEW: THE SolderSmoke STORE: T-shirts, Mugs...!
MAILBAG:
Shawn N3ZHP new to Knack, wants to build ALL his gear
Steve WB6NTL on hippie origins of "Snort Rosin"
Scott AC0GG recommends new mic, equalizer
Jim AL7RV going QRSS mobile. Can we find him?
George K8VU on kid busted by FCC
Craig KC2LFI helps with SS s sounds
David KB1BED says SolderSmoke driving up Drake 2-B prices
Steve G0FUW "Ten DSB rigs built in cloud of aromatic 60/40"
Brian NF0G HBing at -20F Comet Lulin coming
Tony G4LLW Freq standards, IC extraction, Arc transmitters
Kevin AA7YQ listened to SS while on parachute mission
Graeme ZL2GDN building for DSB and QRSS
Stu N6TTO has new FSK QRSS beacon 10140060
Mark K6HX (has great "Brainwagon" blog) lost SSDRA
Robin AF1RE Heard BITx20s on the air, now is building
Gerry EI8DRB has his 2B
Ray M0DHP has a strange aromatic solder experience...

Wednesday, January 28, 2009

My ET-1 / FETer (Transceiver Made with One FET)

Magnificent, don't you think? This is my version of the ET-1 or FETer. It is an HF transceiver using only one active device -- a single MPF-102 Field Effect Transistor. I didn't have a 4 pole Double Throw switch in the junkbox, but I did have a 4PDT relay, so I used the relay. So far I have only built the receiver. It is working nicely. I was listening to German and Polish stations on 80 meter CW this morning.

I had always wanted to build W2UW's ET-1... I've been reading in "Empire of the Air" the inspiring account of Armstrong's invention of the regen receiver... Then, along came SPRAT 137 and G3XBM's FETer. I could no longer resist. Solder was melted.

It is great fun to listen to 80 meters and realize that the only thing between you and the ether is one small FET (you can see mine standing proudly atop the relay!) . Its a lot like using a crystal receiver. That one FET is serving simultaneously as an RF amplifier, mixer and BFO!

On to the transmitter! Thanks to OM Armstrong, to Glen (W2UW), and to Roger (G3XBM).

Monday, January 26, 2009

Minimalist Radio: The ET-1 and the FETer

SPRAT # 137 (Winter 2008-2009) has a number of great articles on minimalist radio -- very simple rigs with low parts counts. Roger G3XBM has a very nice re-make of the ET-1, first introduced by Glen Yingling W2UW in SPRAT 108. I remembered Glen's article -- I always wanted to try it. The ET-1 has just one active device: an MPF-102 FET. And it is a transceiver.
The schematic of the ET-1 appears above. I started building mine yesterday. Got the receiver done and --- WOW! -- heard some 80 meter signals this morning. More to follow...
Designer: Douglas Bowman | Dimodifikasi oleh Abdul Munir Original Posting Rounders 3 Column