Towable Shack Working my rolling shack portable station from air-con comfort We've had a few RV's over the years, but for some reason I've never thought to operate from inside the RV.  I have always tossed a wire over a tree and operated from a picnic table or from my camp chair, as here... But I thought, "Hey, I have a 12v power supply built-into the RV and the built-in ladder makes a nice solid mount for an antenna mast." Early try with a military fiberglass pole mast Now I use a Flagpole Buddy with a 30 foot telescoping mast Here's a link to the f ..read more

Go with a Modern Vibe The DY-88 Power Supply is a marvelous design... for the 1940's.  It could take 3 different DC input voltages (6v, 12v or 24v) and output the 2 different filament voltages (1.5v, 6.3v), plus the low and high B+ voltages (105v, 585v).  It was designed to be as efficient as possible when the radio wasn't in SEND mode (receiver only) by employing a mechanical vibrator and transformer to power the low B+ 105v at about 1 amp current (when running off a 12v input).   Turning low voltage to high voltage Prior to the DY-88, I'd restored a 1960's Heathkit ..read more

High Voltage Electronic Keyer from 1960 I've been interested in getting my hands on a Hallicrafters HA-1 since the first time I saw one online.  A 60 year old (as of this writing) all-tube keyer weighing in at 7.5 lbs.  Everyone needs one, right? The HA-1 uses a mercury wetted relay capable of switching up to 500v circuits.  Wow!  It employs four 12AU7 tubes to perform the mark-space morse timing and uses an OA2 and OB2 tubes for power regulation. They always auctioned for more scratch than I thought was reasonable or were so beat up that I assumed it had been burie ..read more

Silence is Beautiful The space between characters and words is just as important as properly forming the characters. If you're rushing your characters the elements of one character will not be easily discerned from the next and the person your sending to will find it indecipherable and respond with a 73 and spin the dial.  I have a number of comments in my logs about operators who ran their characters and words together.  I tend to avoid those contacts down the log. But, many of us, including myself, are guilty of rushing when we send, especially as a ragchew moves into the 3rd ..read more

Mr. Regula-tor Building a regenerative tube receiver seems to have been a rite of passage for all hams of yesteryear.  Although I built one from a kit (4-States QRP) as my first electronics project a couple years ago I thought I'd go for the real deal and build a vacuum tube regen receiver. I'm building a design based around the 6SN7 tube. While I'm collecting parts and still locating a suitable chassis I decided to build a regulated power supply from the parts I have.  Anyone familiar with electronics could probably whip this together in no time, but being the electronics newbie th ..read more

Heathkit HP-23A and IM-11 I had just buttoned up a HP-23A, after testing its transformer. A fellow ham gave it to me for parts.  This old stuff looks cool, so I took a pic with the phone and thought I'd share.  Feel free to use as a desktop background, but if you use it in on the web or publish provide proper attribution ..read more

? Heathkit VTM model IM-11 ? I recently got a taste for restoring and using vintage vacuum tube radio equipment.  Using equipment that requires 800+ volts for making QRP transmissions is counter-intuitive to the spirit of QRP ham radio, but it's part of my journey as a ham, so I'm writing about it.  Bear with me.  Once I receive a near fatal shock I'm sure I'll move back to 12v powered equipment again. Until then... One of the first issues I ran into while testing the power supplies I restored for my vintage gear was how to measure voltages beyond the range of my digital ..read more

Everyone needs a remote VFO from 1955 Late night eBay surfing, and poor judgement led me to bid on a Knight V-44... and unfortunately won it... Note to self: Never browse eBay just before you go to sleep The 1955 remote VFO was unique because it had a built-in power supply.  It's also interesting that its base oscillation frequency is in the 160m band.  Using harmonics from the base frequency means it doubles for each subsequent band (x2 for 80m, x4 for 40m, etc.)  That doubling means it also multiplies the drift.  Specified drift is 300Hz an hour.  That doesn't sound ..read more

Superstore for Vacuum Tubes When I started restoring my Heathkit HW-101 I thought it might be difficult to find replacement tubes.  I initially only looked on eBay for tubes but then I was directed in a boat anchor forum to the vacuum tube superstore... findatube.com Bob Dubush offers tubes at prices well below what you'll find on eBay.  When you order from findatube you'll receive NOS (new open stock) tubes in their original boxes and may receive them in a nifty original store display box...  Ah I can smell the 1950's  He also carries hard to find tubes like the 6GW ..read more

Tektronix 475 Oscilloscope and Android Signal Generator App When I was debugging problems with my Ten-Tec Century/21, and especially my problematic one-watter kit, I needed to see more than DC voltages.  I carried my problem stuff to my friend Paul to see what his scope and signal generator revealed.  Why would a ham need a scope?  Audio and RF are both AC (alternating current) and a voltmeter alone doesn't offer much insight into that world of voltage across time and phase. I almost bought an inexpensive digital scope last year, then thought better of it.  Then I al ..read more