Boxed-up and Looking Good: An End to "HRO Al Fresco"

The "al fresco" phase has ended for my HRO receiver project.  As has happened with homebrew projects around the world, this rig was literally pushed aside on the workbench to make room for BITX-40 Module Mania.  I began to worry that the circuitry of the HRO receiver might suffer damage from the various kinds of electronic construction mayhem that take place on our workbenches.  Also, I wanted to see what it would look like in the nice big metal box that Tim Sutton had sent me (thanks again Tim.)  And I was hoping that the box would help with the AM broadcast breakthrough that I sometimes hear with this receiver.  So, as you can see, I have good excuses for declaring Basta! on the HRO Al Fresco. 

I think it looks great.  Black on silver is very cool.  It sounds great.  I'm listening to 40 right now. Thanks to Armand WA1UQO  for the very cool HRO dial that got this all started.   

A Package from Hyderabad: Farhan's BITX 40 Module Arrives in Virginia

I am having a really EXCELLENT radio morning here at SolderSmoke East coast HQ.  I made some progress on the Armand HRO receiver -- just squaring away some of the too-long leads and improving the shielding a bit.  Then I was looking out the window as the mailman arrived.  What was that little box he was leaving us?  Wow! A box from Hyderabad!  The BITX 40 module arrived, wrapped in a very interesting piece of Hyderabad newspaper. Very FB. Thanks Farhan.  I will surely be writing and talking about this rig in the weeks to come.

UPDATE:  I just realized that the BITX module fits very nicely into a TenTec TPC-45 cabinet that Armand gave me a while back.  TRGHS.

Cool Jazz from New Zealand as Heard on a Homebrew Superhet Receiver (VIDEO)

I'm making slow but steady progress on this one.  The origin of the project was the beautiful National HRO dial and gearbox that Armand WA1UQO gave me. 

I decided to use a 455 kHz IF because;
1) That was the IF of the old HRO receivers (the ones that won WWII)
2) I had a nice TOYO CM455 crystal mechanical filter that would be good for SSB.
3) I figured it would be easy to add in a wider filter that would be good for AM shortwave listening.
4) I like to keep the IF below the frequency of the VFO.

The wide filter turned out to be harder than I thought, but I think I have finally achieved the selectivity I was looking for.  I'll have a switch on the front panel that will allow me to go from "AM-Wide" to "SSB Narrow." The switch will change the filters and the detectors, and will turn the BFO on and off.

Still to do:  I need a high-pass filter to knock down RFI from nearby AM broadcast transmitter. And an RF gain control would be nice.

I'm really glad Radio New Zealand is there.  It provides welcome relief from the shortwave fire and brimstone.   Radio Romania is also doing a fine job on shortwave.

First Signals from the "Armand HROish" Receiver

I've been kind of busy lately with other things, but I have managed to squeeze in a few minutes most days to work on my latest receiver project.  I call it the Armand HROish receiver.  Armand WA1UQO sent me the big National HRO-style dial and gear box, and he was there at the Manassas hamfest when I bought the dual variable cap that now serves in the front end pre-selector.

I went with a 455 kHz IF.   The idea is to have a receiver that tunes from around 6.5 MHz to around 8 MHz so I can do some shortwave listening AND listen to 40 meters.

So far the filter consists of three IF cans (one small transistor can and two larger tube-type cans).  The small transistor can was given to me by Michael Rainey AA1TJ - thanks Mike. Doug DeMaw suggested this use of IF transformers in his "Design Notebook."

At the front end I have a tunable dual tuned circuit filter followed by a 40673 amp. 

The mixer is an SBL-1.

1st and 2nd IF amps are a 23 db 50 ohm termination insensitive amplifiers.

I have a second SBL-1 that will be the product detector, but I haven't built the BFO yet.  So today I hooked up two 1N34A diodes in voltage double config and -- with a bit of AF amplification, got the receiver inhaling with a diode detector.   I could pick up Radio Canada.  Then I heard SSB sigs on 40.  With no BFO, I decided to put my sig gen on 455 kHz and just wrap the lead around the IF cans.  It worked -- I could listen to SSB and CW sigs.  Very satisfying. 

Still to do:

-- BFO and product detector.

-- Work on AF amp.

-- Get my CM-455 crystal mechanical amp in there with some relays around it so I can switch from narrow to broad via the front panel.

Lots of soul in this receiver:  All parts either 1) came out of the junkbox, 2) were gifts from friends, or 3) were recent hamfest purchases.  The HRO dial from Armand and the IF can from AA1TJ.  The 455 kHz filter idea came from Doug DeMaw, the VFO circuit from SSDRA.  The VFO base is from Whole Foods and the whole thing is built on a kitchen cutting board. It includes a 40673 and germanium diodes. The VFO amps are in Altoid tins.  It will, when finished, go into a big metal box given  to me by Tim KI6BGE and shipped east by Pete Juliano.  And when I was working on the 1st mixer, I accidentally pricked my finger and a drop of N2CQR blood went onto the breadboard.  Of course, I left it there.   SOUL!

The Radio Gods are apparently pleased:  In the first hour or so of listening, I was rewarded for my efforts when I managed to hear Tim WA1HLR on 40 AM describe his troubleshooting of an old piece of gear.  TRGHS.  

Building LC Oscillators

Yesterday I came across this very nice video -- I thought you guys would like it.  2E0VIR obviously has The Knack!

I'm building a very simple LC VFO today. This is for the HRO Dial Receiver that I've been slowly working on. Mine is a Hartley, from Chapter 3 Figure 7 of SSDRA.   Stay tuned!

Building a VFO. A BIG VFO. IF options?

Once again, The Radio Gods have Spoken (TRGHS).  An off-hand comment at the Manassas Hamfest, a bit of encouragement from Pete Juliano, and the next thing you know Armand WA1UQO has sent me this beautiful National HRO dial and reduction drive. This thing is so nice... Well, put it this way: this is the first time I'm building a rig around the dial! 

Further evidence that TRGHS:  I needed something on which to base the HRO dial and a box for the VFO.  Wouldn't you know it:  That Whole Foods "grilling plank" that I bought a few weeks ago was PERFECTLY sized for this task.  Eerie, don't you think?  As for the VFO box, well TRGHS again:  pictured above you see a side view of the box from one of the Heath QF-1 Q multipliers that I cannibalized for the variable caps.    Finally, for the main tuning cap, I took another look at that old brass variable cap that I took out of a 1930's era British regen (pictured above).  It had been hopelessly stuck for a long time.   I twisted it a bit and was amazed to see that it is stuck no more.  TRGHS!  (I just need to find a suitable nut so that I can mount the old cap in the QF-1 box.)

I'm thinking that this VFO will be the heart of a general coverage shortwave superhet receiver.  I want filters for AM and SSB and I'd like it to cover 5 MHz to 10 MHz.  I've been noodling various IF possibilities, but concerns about birdies and spurs keep driving me back to 455 kHz.   I have a crystal-mechanical filter for that freq.  And a big box of 455 kc transformers. What do you guys think of this option?   

HRO (not HOR!) -- The King of Reduction Drives

At the recent Manassas Virginia hamfest Armand WA1UQO and I came across an old HRO receiver. Armand mentioned in passing that he had an HRO dial and drive for me if I wanted one.  When Pete heard this he said I definitely NEEDED one.  Armand heard Pete's comment and very kindly put an HRO dial and reduction drive in the mail for me.

Wow, it is a magnificent thing!  After years of struggling with small Jackson Brother reduction drives and with reduction drives brutally cannibalized out of innocent Heathkit Q multipliers, I now realize that I have been playing in the minor leagues.  This, my friends, is the reduction drive that helped win WWII!  I will have to build something worthy of its inclusion. 

The designation HRO has a wonderful story behind it: 

This is from: http://www.cryptomuseum.com/df/hro/

The new radio was also designed by James Millen at the National Radio Company, but this time with two RF amplifiers and two IF amplifiers at 455 kHz with a 20Hz crystal filter. He kept the pluggable coil packs as part of the design and added the now famous epicyclic dial, which allows the operator to tune the frequency scale in 1/500th units (with the aid of a calibration chart).

The design was finished in 1934 and National pushed hard to get the receiver out by the end of that year. When creating the tools for the first production run, the tool makers had to work overtime and used HOR (Hell Of a Rush) as a job number on their overtime slips. As National's marketing department didn't want their radios to become known as HORs (whores), the name was changed to HRO (Hell of a Rush Order). Despite the best engneering efforts, technical problems delayed the release of the the radio until March 1935. The price at the introduction was US$ 233.

Another site provides tech details and history on the drive itself:
https://www.prismnet.com/~nielw/PW_NPW_Dial/hro_dial.htm

The HRO dial introduced by the National Radio Company in late 1934 was the hallmark of top-of-the-line National receivers from the mid 30s through the 60s. By late 1936 the "HRO dial" was appearing on the NC-100 series of receivers and even the 1-10, National's VHF receiver. Throughout WWII many of the NC-100 variants that National provided to the military used this same dial. By 1950 National had added built-in direct frequency readout to the HRO-50 but still kept the same 0-500 reading dial. Through the mid-50s and into the 60s National mimiced the HRO dial look on their mid-priced receivers such as the NC300, 303 and 270. Even the solid state HRO-500 introduced in the early 60s used a version of this dial. When combined with the required 20 to 1 venier gear drive, the HRO dial provided an effective scale length of 12 feet and was direct reading to 1 part in 500. Ten turns of the dial drives the tuning capacitor stop to stop. Published HRO calibration curves showed each ham band spread over eight turns (or 400 divisions). In addition, dial divisions were about 1/4 inch apart. On all bands below 10 meters the HRO dial is easily resettable to within a KC (or KHz).

"Spine Tingling" Sputnik Recordings From 1957

Doug, W8NFT, sent me this booklet and copies of the recordings that came with it. Below you will find links to the booklet itself and the two mp3 files. Note that the signals were captured using an HRO receiver. Side A is a "re-creation" of the launch ("spine tingling in its realism!!!!") Side B is an actual recording of the sat's iconic beeping.

http://soldersmoke.com/Sputnik Booklet.PDF

http://soldersmoke.com/Sputnik Side A.mp3

http://soldersmoke.com/Sputnik Side B.mp3

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics"http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20

Ham Radio Time Capsule at University of Virginia

Bert, WF7I has been sending us some great info from the University of Virginia's radio club. Listeners will recall his adventures in putting up and taking down the rhombic antenna. This week Bert sent in excerpts from his research on the history of the UVA club. This bit came from Lee, KD4RE. I know there are a number of "anchor-ologists" out there (fans of the Boatanchors i.e. big, old tube radios). I thought you guys would get a kick out of this. Oh, wouldn't you want to find a room like this one?

Back in 1971 a student named Bill Hughes was Ham and knew I was a ham
and he wanted to get the UVA Ham radio club started up again. There
were a couple of other Hams around, Dave Wolfe who was Chief Engineer
at WTJU before me, has a 2-B receiver in the engineering (transmitter
room) at WTJU when in was in the basement of Humphreys.
(Yeah I have a lot of WTJU Stories..).. Anyway Bill told me he heard
that the last active ham radio club had been located over in one of
the ground rooms behind Varsity Hall (which has since been moved to
make room for Rouse Hall expansion) In those days it was the Air Force ROTC building. Anyway, the ground level had a brick floor and sort of an open portico and across the back were a bunch of rooms (all brick of course). well we came to the old door and saw open wire feeder remnants overhead We opened the door and it was like opening a time capsule - There in the room was mostly 1930s and 1940s vintage gear, I guess it had not been used since the mid 1950s (or early 1950s).

There was a rack with an AM transmitter in it, sort of a copper
colored paint on the front and on it was a piece of cardboard with the call sign W3VA. There were a number of old receivers in the
room I recall a National HRO with its plug-in coils there was and RME
receiver with a tunable preamplifier/selector as a separate box, and
several others. I am not sure but the DX 100 we had for a while may
have come out of there so that would have been late 1950s then...

For more UVA Radio Club history go to:
http://www.student.virginia.edu/~w4uva/file-storage/history/index.html

W4HBK's QRSS Grabber: The Amazing Pensacola Snapper

When we were in Italy, ON5EX provided my "go to" grabber. Because we were just one ionospheric hop away, and because Johan had a really excellent receive system, it seemed like my little signals were visible on his screen from dawn to dusk every day.

Now that we are back in the States, W4HBK's grabber is playing a similar role for me. His grabber consistently seems to pull in more sigs than most of the other North American grabbers. The above image is a sample of what you will see when you visit his grabber web page. (I'm also a big fan of the W1BW and VE1VDM grabbers -- thanks guys!)

My signal is the "shark-fin" pattern just a little below the middle of the screen. That's 20 mw to a 50 foot piece of AC line cord about 12 feet off the ground. And it is making the trip from Northern Virginia to Pensacola Florida very consistently. Thanks Bill!

Try taking a look at the Pensacola Snapper and see if you can spot my QRSS signal. My frequency varies from day-to-day (sometimes intentionally!). And lately Bill has occasionally been parking his receiver on 40 meters :-( But most days you will be able to see his 30 meter screen, with my shark fins menacing Pensacola. Please let me know if you see me.

Here is OM HBK and his bio:
Born: 1939, Pensacola, Florida

I was first licensed in 1954 as WN4HBK and upgraded to General in 1955 acquiring the call sign I've used to this day. My dad is responsible for my favorite suffix moniker. the Hot Biscuit Kid. I could really put away my mom's scratch biscuits!

My first station I built myself and consisted of super regenerative RX and a 6L6 TX.from designs in the ARRL Handbook. My dad was a radio mechanic for the Navy and taught me how to read schematics and solder. Later stations consisted of Hallicrafters S-38C, National NC-98, HRO-5 recievers and several Heathkit and Globe Scout transmitters. Boy, those were the days!!

After high school I entered college intending to become an antenna engineer but eventually gravitated towards a degree in Physics. This was pretty cool because it led to a career with NASA where I worked on the Mercury, Gemini, Apollo and Space Shuttle projectsall thanks to my early interest in radio.

Today I'm fully retired and living in Gulf Breeze, FL. just across Pensacola Bay from my hometown. My XYL (Anna) and I enjoy the local beaches in a variety of wayssurf fishing, beachcombing, hiking, painting (her) and photography (me). We are also enjoy gardening and winemaking.

My Amateur Radio interests are CW, DX, contests, antennas and digital modes.

Presently I am experimenting with QRSS and have a 250 milliwatt MEPT station on 10.140 MHzsend me an email if you copy my signal. I now have a grabber to present a spectral display of QRSS activity for other Hams worldwide to watch for their signals http://www.qsl.net/w4hbk/w4hbkgrabber.html

Glowbug Christmas

My "Mate for the Mighty Midget" receiver (with 6U8s)

Some excellent Christmas verse from Brad, AA1IP:

The Glowbugs' Christmas
******************************

T'was the night before Christmas
And all through the shack
Not a heater was glowing
In all of the rack.

Sitting totally silent and quiet that night
The old HRO shed nary a light.
The Johnson exciter and its homebrew final
Felt cold as leftovers, or seat-cover vinyl,

I drowsed at my workbench feeling tired and weary,
The print in the Handbook looked fuzzy and smeary.
I thought, "I'll make coffee", and groaned to my feet
When I heard a loud clatter outside in the street.

What the--? I wondered and turned on the lights
And there I beheld a wondrous sight:
A battered old van heaped high with components
And a grizzled old ham with a bagful of doughnuts.

I noted his callsign-- can't recall it today--
But a patch on the side read "FMLA".
I opened the door and hollered "Come in!
The coffee pot's heating, and we'll sit down and chin!"

He spoke not a word but whistled in Morse
A "GE OM", and "By golly, I'm hoarse.
Too many contacts, and hot rosin smoke."
I nodded and poured him a mug of jamoke.

He emptied the doughnuts in a pile on a plate
And explained in a whistle, "I'm running real late.
I've new 6L6s and fine 211s, 6146s and good 'SN7s.
And 866s and 0B2s, type 45s and mil-spec 807s."

"For the regennie crowd, 201s by the score
And good ol' type 30s and 19s galore.
I haven't neglected the passive-parts run
There's lots of good iron by old Thordarson."

I nodded and smiled, suppressing a chortle
As he reached in his pack and left me a 304TL.
He whistled, "I'm leaving, the coffee was great,
But I'm overdue in the neighboring state."

"Keep everyone building the rigs of their choosing
Or we'll lose the bands that we're lazy in using.
Transistors or tubes-- any project is fine--
Just keep on constructing and sharing on line."

He leaped to his feet and waved a gloved hand
As he sprang for the door and his rusty old van.
I heard him exclaim as he drove away from me,
"Merry Christmas, you Glowbugs, and to all 73!"

****************************

(With apologies to Clement Clarke Moore, who surely would have
been a ham had radio existed in his time. Alas, all he had
to build with was words.)

For new readers: the FMLA (Five Meter Liberation Army) appeared in a
series of short stories written by Michael N. Hopkins, AB5L (sk). If you have never
read these, you're in for a fun evening!

For QRP fans: the numerical references in the poem are for classic
vacuum tubes, several of which operate at QRP levels (whether or not that was the
original builder's intention) and (mostly) within the amateur bands.