Month: May 2020

QCX SSB — But How Much QCX Remains?

Hack-A-Day carried a very nice video describing recent efforts to turn Hans Summers’ amazing QCX CW monoband transceiver into a multi-mode, multi-mode (including SSB) rig (see above). This is project will greatly interest QCX and SDR fans.

But I wondered how much of the old QCX is still there after the modification. Not much, it turns out.

Here is the bloc diagram of the QCX. It is essentially a phasing rig, using the same principles as my venerable HT-37 transmitter and my version of KK7B’s R2 receiver:

Yesterday Paul VK3HN sent me the schematic of the new multi-mode, multi-band version:

Notice how different it is. I thought that perhaps the new rig would keep something of the I-Q circuitry of the QCX, but it does not. This is not a criticism, just an observation.

But here is something that harks back to a topic we’ve been debating on the blog and podcast. Notice that the top diagram is a bloc diagram. There is a lot of circuitry in most of those boxes — lots of resistors, capacitors, inductors, and transistors. There is a schematic diagram under that bloc diagram. But look at the second diagram. While it looks like one, that one is NOT a bloc diagram. That IS the schematic diagram. Most of the circuity has been sucked into the chips.

While many will prefer the rig described by the second diagram, I remain an HDR guy, and don’t really like seeing the circuitry disappear into the ICs. But, to each his own. This is all for fun. Congratulations to the guys working on the new rig.

Tribal Wisdom from KE3IJ

Lots of homebrew wisdom on OM Rick’s web site. Excerpts:

—————-
Why am I not on the air as much as I’m tinkering with toy radio circuits? Well, if some of the hams reading this don’t mind my saying so, the manners of many of the people using the bands these days leaves so much to be desired that I often find more pleasure in futzing around with “minimal” QRP [low-power] ham-band transmitters and receivers, as well as good-old AM broadcast receivers, than in getting on the air anymore.
So I’ve found a certain twisted fascination with trying to build the simplest pieces of junk possible, and seeing what I can pick up with them. I usually start by drawing a rough schematic on paper, then tack-soldering a haywire “spider-web” of components, as a ‘first pass,’ and then I rebuild the circuit more neatly once its design is finalized.

It still amazes me that we can connect some modified “rocks and sticks” together (that’s basically what copper wire, silicon transistors, etc. really are, when you think about it) and hear voices and music magically appear out of nowhere…
————-

 He has many regen circuits. And his Drake 2-B dial skirt looks just like mine.

Visit Rick’s site: http://ke3ij.com/radios.htm


Antennas, Money, and Ham Psychology

During SolderSmoke Podcast #222, Pete lamented the fact that many hams are willing to spend significant amounts of money on “manufactured” dipole antennas that are little more than pieces of wire. Tony Fishpool G4WIF sent a graphic on the wire antenna he uses (see above). He also shared an anecdote about G5RV antennas and G-QRP Club founder George Dobbs:

From Tony:

The aerial that I’ve had so much fun with, an End Fed Half Wave, cost me £8 ($9.80) for the toroid and the rest came from the junk box. The reel of wire was probably a £1 ($1.25) from a radio rally. You never pay big money for wire at a rally. People take it there to get rid of
it!


It covers 80m and all harmonically related bands.
My garden is too small so I cheated by using some linear loading to
make it fit. (on the back fence).

WIth 5 watts CW on 40m I can hit the USA reverse beacons most mornings.

It was about £9 ($11) to make – but if you count the Spiderbeam
12m pole, it was another £98 ($120).

 I have a little George Dobbs story relating to aerials. Probably around

15-20 years ago. He was speaking at a radio club near to me so I went along to support
him and have a beer with afterward.

He gave his usual entertaining (and always funny) talk during which he
paused – and said, as if in confidence to the audience:

“Do you know, I’ve heard, and I don’t know if it is true, that there are
people who actually pay real money for a pre-made G5RV”

I swear that it went very quiet and there may even have been the odd foot
shuffled. Tony
———————————————————

Coincidentally Mike, WU2D put out a VERY ILLUMINATING YouTube video on the psychological aspects of ham radio operators and their antennas. Here it is:

Emilio’s Mirror of JF1OZL’s Site

JF1OZL’s site was for many years a real treasure trove and source of inspiration for homebrewers around the world. It recently disappeared from the internet. And I find no listing for JF1OZL on QRZ.com. I hope Kazuhiro is OK.

Emilio in Mexico has put up a mirror site. Thanks Emilio. We need to protect and preserve JF1OZL’s work.

https://www.emilio.com.mx/jf10zl/

Here is a SolderSmoke blog post on Kazuhiro from 2011:

https://soldersmoke.blogspot.com/2011/12/homebrew-hero-kazuhiro-sunamura-jf1ozl.html

SolderSmoke Podcast #222 Antennas, Phasing, VFOs, 2-Bs, 6 years of N6QW, MAILBAG

After 46 years, finally a dial skirt
SolderSmoke Podcast #222 is available:
http://soldersmoke.com/soldersmoke222.mp3

No travelogue but… SolderSmoke Almanac!
Memorial Day in U.S.

End of Ramadan so Eid Mubarak!
#222 marks SIX YEARS of Julian-ismo. He started on SS 161. Thanks Pete.
Thanks to all who sent good wishes on Billy’s graduation. He heads to Boston and the lab in a week or so. Very proud.
——————————————
Bill was on Ham Radio WorkBench Podcast
—————————————–

PETE’S WORKBENCH
— Antenna Ideas — Don’t Buy that $165 dollar dipole! It is just wire!
— THE PHASING RIG. Does this point to a need for meditation? Or at least some temporary disengagement? Tribal wisdom from Pete.
— DEAN KK4DAS’s rig. The Furlough 40. Troubleshoot. Tribal knowledge.
——————————————-
— SHAMELESS COMMERCE DIVISION: AMAZON BOX — SEARCH FOR ANYTHING OU WANT THERE.
— PLEASE PUT COMMENTS ON THE SOLDERSMOKE BLOG POSTS.
— PLEASE CHECK OUT THE SolderSmoke YOUTUBE VIDEOS.
——————————————

BILL’s WORKBENCH
n Shortwave dials and exotic locations. Java!
n Galaxy V VFO Project. Series-tuned Colpitts.
n DRAKE 2-B. Hayseed Recap. Put the skirt back on the old rig. Reduction drives?
SHOPPING BAG:
I got a replacement for the Xtronics 4000 soldering station. Yaogong worked!
https://www.amazon.com/gp/product/B078WB9Z2R/ref=ppx_yo_dt_b_asin_title_o02_s01?ie=UTF8&psc=1
Ordered screws and stuff from McMaster — Came very fast!
Working on a resistor kit from Mouser.
MAILBAG:
VK2BLQ’s Phasing RX with an HRO dial. Cool Retro.
Adam N0ZIB — Cool station. TFT screen Aluminum welded box. FB.
Karl G7AFT BITX 40 doing USB and LSB by changing the VFO freq. Pete’s trick!
Jerry KI4IO out in nearby Warrenton. Hope to be able to meet up soon.
Keith N6ORS’s Hot Mustard Phasing Board.
Mike N5GTF’d FULLY INDOOR Quarantine Receiver. Need a slogan for the antenna!
Nick M0NTV’s Bread Bin 80 Quarantine rig
Bruce KC1FSZ Quarantine 10 — Brave man in solar minimum. But I hear 10 is opening.
Talking to Grayson Evans KJ7UM TA2ZGE about Collins 9.9 MHz transformers.
Talking to Alan Wolke W2AEW about Drake 2-B stuff Was there a reduction drive?
Paul VK3HN about Ceramic filter spurs.

Peter VK2EMU notes no animals were harmed in the making of my videos. But many electrons were agitated.

N6QW Phase Shift Success — It aint over ’till the fat lady sings




I,Q, and HRO: VK2BLQ’s Phasing Receiver with an HRO Dial

I had occasionally fantasized about connecting Armand’s HRO dial to the rotary encoder of an Si5351, but I think this was more of a nightmare than a fantasy. I don’t think Stephen VK2BLQ went this far — I suspect that his HRO dial was connected to an analog VFO. But still, the combination of HRO with I&Q seems a bit edgy… FB Stephen. Please send us more info on this amazing receiver.
Hi Bill,

Hope you are safe there with the bad weather.

Recently you mentioned HRO dials and the need to build a radio around one and Pete has been discussing phasing SSB; attached photo is a phasing receiver on 80 and 40 m, a combination of both HRO and IQ that I built many years ago, and thanks to Pete I shall get it running again.

And Bill, like you I am from the IGY of 1958 and retired with more free time on my hands.

Best regards to you and your family, especially young Billy.

Stephen,

VK2BLQ

Replacing Electrolytic Caps in my Drake 2-B (Video)

Every dark cloud has a silver lining. Here is a very small silver lining for this terrible COVID-19 situation: I had time to do a proper replacement of the electrolytic capacitors in my Drake 2-B.

Three cheers for Hayseed Hamfest LLC for providing the replacement capacitor.
Go to their website to find capacitors for many other old rigs:
http://hayseedhamfest.com

Homebrew Az-El Satellite Antennas from the Philippines and Australia

https://nightskyinfocus.com/2020/05/18/diy-satellite-tracker/

DU1AU is way ahead of where I was when I was working with Low Earth Orbit satellites. I just aimed the antenna about 45 degrees up from the horizon, and spun it around with a TV rotator with me –not the computer — as the controllers of the rotator. In essence I did the AZ manually and completely ignored the EL. This design moves the antenna in Azimuth and Elevation, and has the computer control the movements via an Arduino. FB.

DU1AU points to the work of VK3FOWL and VK3YSP. Their site has very detailed info on how to build several versions of this kind of Az-El rotator:

https://www.sarcnet.org/rotator-mk1.html

 This Az-El project represents a great opportunity to move beyond hand-held satellite antennas, and beyond my Az-only manual approach. It also give us a way to bring some real homebrewing into a part of ham radio that has come to be dominated by commercial equipment. There are some Arduinos and some lines of code, some motors and some metal work. Great stuff!



Nick M0NTV’s Quarantine Rig: The Bread Bin 80


 Hi Bill,


Hope you are keeping well and staying safe.

Just thought I’d let you know about a homebrew project I’ve just completed. I call it the Bread Bin 80 – you’ll see why!

It is a single band (80m) SSB transceiver that puts out 25-30W of clean RF. It uses the familiar pairing of Arduino Uno + Si5351 (with 16×2 LCD screen and rotary encoder for tuning). Other than this though it is largely an analogue beast – which I thought you might like!

I made my own double balanced mixers which work really well. But the Si5351 can’t generate the 7 dBm of local oscillator signal to drive them so I then had to build a simple one transistor RF amp for each clock of the Si5351. I even went above and beyond the call of duty and home-brewed my own IF crystal ladder filter (although this was actually a kit).

The rig has a three stage IF cascade amplifier with 2 back to back JFETs in each stage + AGC and analogue S meter. There is something very satisfying about seeing the needle bob about as you are listening. I also put in a switchable analogue audio filter in front of the audio pre-amp which cuts out some of the higher frequency noise on the band.

Overall I’m really pleased with the rig. I’ve been working stations all over the UK and into continental Europe and getting some great reports. Except the one guy (who shall remain nameless) who wasn’t the least impressed that I was working him on a homebrew rig: he was only keen to point out that my antenna must be far too low to give me such an attenuated signal!!! I guess you can’t please everyone.

Anyway, I’ve done a bit of a write up and included some photos (outside and in) on my QRZ page if you are interested:

https://www.qrz.com/db/M0NTV

Thanks for sharing your home brewing story about your short wave receiver on YouTube. I’ve enjoyed following that and seeing it progress. Those little ‘Altoid’ tins are great aren’t they.

Thanks again for all your encouragement through the Soldersmoke podcast. I really enjoy it.

Stay In The Shack!

73 from across the Pond.

Nick

M0NTV
Nick Wood
www.nickthevic.co.uk

N5GTF’s FULLY INDOOR Quarantine Receiver and Antenna

Mike N5GTF deserves special recognition for his truly remarkable SITS (Stay In The Shack) quarantine project. It is not hard to build receivers and transmitters that stay in the shack; Mike went the extra mile by keeping even his antenna inside during lockdown. Well done Mike! But that cardboard frame for the antenna seems to be crying out for some sort of inspirational slogan. Can we get a big “SITS!” in there? 73 Bill

Hi Bill,

Thought I would share a few photos of what happens when one randomly selects things from the junk box after being inspired by Pete’s recent posts about phasing SSB. It starts with a 10.7MHz crystal filter because it was large and shiny. This will prove to be somewhat inauspicious, but I’d had a pair of them for longer than I can remember… Then there were several ferrite toroids and a handful of swap meet diodes. Instant mixers, (just add enameled wire). A few 2N3904s and an MC1350P, plus a few more toroids (and wire). I’d picked up some TDA1015s awhile back. They have both a power amp and a preamp, so one of those as well. Also, an Arduino and Si5351, because Charlie Morris, ZL2CTM, has been so generous in sharing his knowledge on how to use them. Finally, about 12 feet of 14/2 w/G and a 365pF variable cap for an indoor mag loop.

Not the best reception though not bad considering the antenna’s in the basement with house wiring and metal duct work in the ceiling. The biggest issue is the IF and my choice of LO frequency. I’ve got the LO below the IF and the LO second harmonic falls inside the 40 meter band. Definitely need to fix that and move on to the transmit side.

Visits to both SolderSmoke and Pete’s blog are on my daily agenda. Thanks to you both for the frequent updates of interesting content and for providing a way to get out without going out.

Mike, N5GTF
www.mikesflightdeck.com

Video on the Galaxy V VFO Project

This is the second version of this video. I had some technical difficulties getting it to upload in High Definition, but I was able to work it out in this version.

In this video I describe the VFO project, talk about how I made use of the e-bay Galaxy V parts, talk about the circuit (series-tuned Colpitts), conduct some stability tests, and discuss many of the ways a VFO like this one can be useful to the radio amateur.

Thanks to Pete Juliano for inspiring this effort.



An Understandable Chip: The LM386

Over the years I have made my distaste for integrated circuits very clear. I’ve presented them as mysterious little black boxes that don’t really belong in our homebrew rigs, rigs that we are building, after all, because we want to avoid the use of MYSTERIOUS BLACK BOXES.


So, I don’t use voltage regulator chips — I use Zener diodes. I prefer analog LC oscillators to AD9850s or Si5351s. And I have repeatedly built discrete component audio amplifiers when most normal people just put an IC AF amplifier in the circuit.

When I built the Q-31 Shortwave AM receiver, I kind of ran out of gas at the end. I wanted to get the receiver going and I didn’t want to build yet another discrete AF amp. So I used an LM386.

I rationalized this deviation from cherished values by noting that the discrete AF amplifier circuitry that I was using was remarkably similar to what exists inside the LM386. So that little chip is just as understandable as my discrete component creations. It wasn’t REALLY a mysterious black box…

Around this time I found a web site that made me feel mush better about all this. It explains very nicely how the little LM386 does such a great job. It really packs a lot of amplification into a very small package. Here is the web site:

https://www.electrosmash.com/lm386-analysis

Shortly after my transgression, Jenny List over at Hack-A-Day posted a nice piece looking at the inner workings of Op-Amps. Who knows, I may seen be using 741 chips too!

Here is the Hack-A-Day piece:

https://hackaday.com/2020/05/09/an-op-amp-from-the-ground-up/

Bill Meara Graduates with Honors from James Madison University

Deep thoughts where Faraday lectured
He has been part of the podcast and blog since the beginning: Camera kites, video rockets and crystal radios. Drones and exploding corn starch. The Trivial Electric Motor. Visits to Faraday’s lab and Marconi’s house. Billy helped me wind toroids at age 2!. He went with me to hamfests in Virginia and in London.

Toroid by Billy (at age 2)

Here are just some of the blog posts in which Billy is a key player: https://soldersmoke.blogspot.com/search?q=Billy

This video demonstrates Billy’s early interest in biotechnology:


And of course, he is the guy who says “Ooo! That’s awesome” in all of the podcasts.
Yesterday was a big day: We are very proud of our son Bill Meara who graduated with honors yesterday from James Madison University. Bill earned his Bachelor of Science degree in Biotechnology. In a few weeks he will be heading to Boston where he will start work at a neuroscience research lab of Harvard University.

2020 Virtual Graduation

Billy’s mom, sister and dad watching the graduation

Graduation: Oooo! That’s Awesome!

QSO Today — Episode 300 — Panel Discussion

Congratulations to Eric Guth, 4Z1UG for reaching episode #300 on his QSO Today podcast. To commemorate the event, Eric organized a panel discussion. It was a real pleasure and honor to participate.

Listen to it here: https://www.qsotoday.com/podcasts/300

Thanks again Eric!