Author: Peter Marks

Of Waterfalls, SDRs, and Homebrew Analog Rigs: Words of Wisdom from W8JI

W8JI


 It happened again today. Conditions were good and I was BOOMING into the NYC area on 40 meters. 40 over. Everyone liked the signal and said it sounded great. Except for one anonymous grump who chimed in to say that I was “9 kc wide.” I imagine he was basing this on a quick look at his super-dooper SDR waterfall, without any consideration of signal strength or the characteristics of his own receiver. Sigh. The Waterfall Police had struck again.

OM W8JI gives a great description of the pitfalls of this kind of “you’re-too-wide-because-my waterfall-says-so” reasoning. Check it out. And keep it handy in preparation for your next encounter with the 40 meter Waterfall Police.

https://www.w8ji.com/checking_bandwidth_with_receiver.htm

Wonderful “QSO Today” Interview with Ian Keyser G3ROO

N2CQR and G3ROO
I knew it was going to be a good Sunday morning in the shack when I saw that Eric 4Z1UG had posted an interview with Ian Keyser G3ROO. This wonderful interview brought back memories of my visit to G3ROO’s amazing facility in Dover. (Thanks to Tony Fishpool who brought me out there.)

In this interview, you will hear Ian state — in a very nonchalant English way — that he built his first receiver at age 8. And I really loved the story of how Ian got his call sign. FB Ian.

Ian is a very prominent member of the G-QRP club. I was oddly relieved to learn that he is working on a LEGAL LIMIT LINEAR AMPLIFIER. I hope he has special dispensation from Rev. George Dobbs. I intend to cite this project if we ever have to defend Pete Juliano from charges of QROism.

Listen to the interview here:

http://www.qsotoday.com/podcasts/g3roo

That is a key designed for use aboard a hydrogen balloon. This is the kind of thing that Ian has in his shack.

This is Ian’s variometer — mentioned in the interview.

That’s me using one of Ian’s spy sets.
Ian’s antenna book:
http://www.lulu.com/shop/ian-keyser/practical-and-tested-aerial-systems/paperback/product-10904725.html
Here are the SolderSmoke Daily News posts about Ian and the Dover Construction Club:
http://soldersmoke.blogspot.com/search?q=Dover


BITX40 to BITX40 In Australia — Both Rigs on the Beach, Video at Both Ends

There is so much great homebrewing going on down-under. It makes me jealous. And so much of it is for phone. FB.

I really like VK3YE’s sand graphic proclaiming to the world (or at least to the beach!) that a BITX40 to BITX40 contact had been made.

Looks like both rigs were using VK3YE’s ceramic resonator mod for the VFO.

Be sure to check out the BITX 40 Mods blog:
http://bitxhacks.blogspot.com

N6ORS’s Franken-SDR Superhet

Of course, I love it. MOSFETS! NE602’s! 10.7 Mc IF cans! Cycles, not hertz! And a Tayloe Quadrature Sampling Detector made from junkbox parts from the Reagan administration. FB Keith. And the frequency display is icing on the cake.

Bill:

I thought the group might find my new Franken-SDR interesting.
It is an SDR with a superhet front end.

I wanted to play with an SDR but I didn’t want to get a kit or buy
parts, so I scrounged through he drawers and found a mux chip
cd-4016 circa-1980 some old 7400 logic that is probably per-1980.
This could make a QSD but only very low frequencies. Well I thought
how about at IF frequencies?

The frontend is a MOSFET mixer (1975) , the 10.7 IF is a dual gate MOSFET
(1975), the second mixer is a NE602, the IF cans are all stagger tuned to
give a bandwidth of 50kcs.
The only thing modern is the DDS but I old-time-ifyed it with BCD switches.

 Keith N6ORS



VK6FTH did something similar: http://www.vk6fh.com/vk6fh/SDRradio.htm

Boatanchors! HT-37 to HT-37 contact with W1ZB

Jerry W1ZB and I met up on 40 a week or so ago. He was running a Hallicrafters HT-37. This spurred me to clear up the T/R problem that had knocked me out of the competition on Straight Key Night (I’m sure I would have won!). One spray of DeOxit D5 on the HT37 relay contacts was all it took. Jerry and I set up a schedule for this morning on 40 minutes. Above you can see a short video of the first part of our HT-37 to HT-37 contact.

Jerry has an amazing collection of beautiful old tube radios. Check out his QRZ.com page:
https://www.qrz.com/lookup/w1zb

BTW: Speaking of old rigs talking to identical old rigs: Last night on 40 I worked TI2NF in San Jose, Costa Rica. He was running a Collins KWM-2 to a Collins 30-L1. It was real nice to talk to somebody who was using an unusual rig. Right after we finished, VE3OCZ called TI2NF. VE3OCZ was ALSO running a KWM-2 to a 30-L1. TRGHS.

Great Interview with Farhan Re BITX 40 and BITX History

W5KUB has a really good interview with Farhan. There are several spots where the Skype connection gets quite choppy, but hang in there — it gets better. Farhan provides a lot of good info on the history of the BITX rigs, his design philosophy, and the importance of the EMRFD book. He also talks about how the BITX 40 Module is produced. And he talks a bit about possible future rigs. Great stuff.

I was very pleased to hear that Farhan is trying to eliminate the need for his FT-817 (he currently needs it for its general coverage receiver) so that he can have a completely homebrew hamshack. FB!

NE602 Si5351 OLED “Whole Foods” Receiver

This is one of those projects that sort of just happened. First I built an Si5351/Arduino synthesizer with a small OLED I2C display (program by Thomas LA3PNA — thanks Thomas). Tom Hall AK2B up in New York helped me get the Si5351 VFO and BFO going — thanks Tom. Then, over the holidays I decided to build a rig of some sort around the Si5351. I started with a superhet receiver using an NE602 as the mixer and another as the product detector. I power the NE602 with an 8 volt regulator from W8NSA — thanks Jim. I made a 4 crystal 11 MHz Cohn filter using crystals left over from a BITX project. The software from AADE helped me design the matching networks to match the filter to the 1500 ohm impedances of the NE602s. I built the circuits on a milled board sent to me by Pete Juliano N6QW — thanks Pete! I put a dual tuned circuit at the front end, going into a MOSFET RF amplifier. For audio amp I have an LM386. The whole thing is screwed down to a barbeque grilling plank from Whole Foods — thanks Whole Foods! (This seems appropriate — the “O” in OLED is for “Organic”!)

 It sounds nice. I may eventually try to put some relays in to switch the NE602s and the filter around to make this a transceiver.

Straight Key Night — Bandscan from WA6ARA (audio)

WA6ARA SKN Station

Mike Herr WA6ARA was on 40 meters with old gear this Straight Key Night. Mike was receiving with a venerable Heath HR10B. One of his favorite QSOs was with Keith W6SIY; Keith was running Conar twins that had the kind of “swing” that stirs up the kind of memories that SKN is all about. FB. Mike made a bandscan recording of what 40 sounded like, and he made another of W6SIY’s beautiful signal.

You can listen by clicking on these links:

http://soldersmoke.com/SKNBANSCAN.mp3

 http://soldersmoke.com/SKNQSO.mp3

 My own SKN effort was cut short this year by technical difficulties. The HT-37’s relays stopped doing their thing. Probably the relay drive tube going soft. But I did manage to make two great contacts on 40:

WA6URY is in Los Angeles. This was a very timely contact — my wife and I went to see the movie “La La Land” on New Year’s eve — the film features a lot of beautiful LA scenery. Dan was running a kilowatt to a 2 element Yagi on 40. He too owns an HT-37 and a Drake 2B. He was on a straight key “with dirty contacts.” FB Dan, thanks.

And then I worked W1PID! Wow! Jim is well known for his operations from field locations and for his intrepid participation in many of the radio adventures of Michael Rainey AA1TJ. Jim was on the Maine sea coast expedition when Michael was attempting to cross the pond with his voice-powered radio. On SKN Jim was in New Hampshire running 35 watts to a Windom off-center fed dipole. His Morse key is a Kent. TRGHS. Thanks Jim.

Happy New Year!

W1PID Maritime Mobile

Homebrew SSB in Germany: DK7IH

Pete WB9FLW alerted us to the work of Peter DK7IH, a very talented homebrewer who recently followed the lead of Pete N6QW in building some really small SSB transceivers. Here is his Micro QRP SSB rig:

You can see more of his fine work here:

https://radiotransmitter.wordpress.com/

 https://www.qrz.com/db/DK7IH

 Have you guys noticed how many Peters there are among homebrewers, especially among SSB homebrewers? Just from recent mentions on this blog:

Pete Juliano N6QW
Pete WB9FLW
Peter Parker VK3YE
Peter DL3PB
Peter W1UO
Peter GW4ZUA
Peter G6GNR
Peter VK2EMU
Peter VK2TPM
Peter HA5RXZ
Peter DL3JIN

Christmas Present! 4Z1UG’s Interview with Han Summers G0UPL

I found myself almost cheering out loud as I listened to this wonderful interview, especially at the point where Hans lets it be known that he has NO COMMERCIAL HAM GEAR in his shack! Yes! That’s the ticket! You can also hear the story of Hans and Farhan meeting up in Mumbai for dinner. The interview includes discussion of WSPR and QRSS and BITX and crystal ovens and, at the end, a special QSO TODAY overtime session in which Hans describes the little WSPR rigs that fly around the world, carried aloft by half-filled birthday party balloons.

Thanks to Eric 4Z1UG and Hans G0UPL for this very nice Christmas present.

Listen here:

http://www.qsotoday.com/podcasts/g0upl

A Nice History of BITX 40 Module: Production and Finance

Some fellow jumped into the BITX20 yahoo group this morning, casting aspersions on our friend Farhan. The fellow alleged that a lot of money was being made on the BITX 40. He seemed deeply unhappy about the shipping materials and found fault with the documentation that came with the boards.

Farhan came back with a very gentlemanly and detailed response. He was a lot more patient and temperate than I would have been. And when I think about how Pete would have responded, well, it would likely have involved — at the very least — a lot of colorful words from Southern Italy.

Anyway, below (unedited) is Farhan’s response. I think it provides a lot of very interesting background info on our beloved BITX 40 Module and on the place that these boards come from.


thanks for writing in, I couldn’t get your handle from the mail, so do excuse me for improper address! I think you have raised from valid points. I think it is important that everybody understands what tried to do, what we did and where we are now.


this is going to be a long and full of personal details that i didn’t consider to be of any interest to the group and hence it was kept out. but i guess, i need to let a few cats out of the bag.

i am retired, early. i had a modestly successful run in a few businesses but i had promised myself to retire from active work, which i did around five years ago. i no longer run any for-profit businesses. most of my investment goes into ‘stuff that matters’. i founded a libera cultural space in hyderabad, i am a partner in a strategic venture fund that promotes technologies that are important rather than profitable. neither ehsan nor i are any longer running anything full time. i do mentor some startups now and then but never as an investor.

i would be only too glad if someone else takes over the entire hfsigs approach. the design has been out in the open for more than a decade. apparently, it doesn’t make economic sense to make them at $45 dollars a pop. so, there is nothing preventing others ‘creaming the market’ if they want to. surely, the turnover is modest but it is not profitable.

it is fallacy that India is cheap. In Hyderabad, a modest apartment will cost you over 250K USD. An independent house in a reasonable area goes for a million USD. A gallon of gas will costs you more than 5 dollars. smart people are hired by facebook, google and microsoft. they have a big a presence here as in the valley and seattle. there is no healthcare, all education is privatized and has to be paid. there is no social welfare. the multinationals they pay top dollar and that drives the living index up, not down. a quick indicator is that only 7% of the population of Hyderabad moves in cars and taxis and they account for 85% of the traffic congestion. our purpose is not provide the women who work low wages, but respectable wages. but i am getting ahead of myself…

Two years ago, our local club conducted India’s annual hamfest. As a part of the delegates kit, Ehsan and I decided to put free BITX PCBs in the kit. These were done without any commercial interest. At this time, the hamfest was still short of money, so we decided to buy the back page ad of the souvenier to help them with the money. I had to put in something in as text, I decided to put a message in the name of HF signals (which was the name of the wiki that is still up at www.hfsignals.org). We distributed a 1000 PCBs for free. Only a few turned up on Air. It was time to do something.

Later, in 2015, I decided to conduct a workshop to help those interested in assembling the PCBs. asked them to get the components off the local shops and we settled down to do it. i discovered that a seemingly simply job of scrapping the enamel off a copper wire would take them hours and often they’d end up doing it the wrong way. the PCBs were badly designed too. we aborted the attempt. i had learnt something : homebrewing cant be taught in a day. first fail.

i also figured that it might be easier to begin with something that is already working and then start modifying it. something that happens in open source all the time. so,i sat down and designed a new single side pcb .. with through-holes, on Express Pcb. we turned up 100 boards, found a group of five young girls who were laid off after the unit where they worked to assemble TVs had closed down. showed them how to assemble the boards. they made quite a few mistakes. the transformer windings got mixed up, resistors got swapped, the transistors were inverted, etc. each board was an adventure. you can probably see some pictures of these boards floating around. they were cheap to produce. the actual component cost of the bitx is ridiculously low. it cost us about 1000 rupees in components, another two hundred for the assembly and testing and a hundred bucks to ship it. we rounded it off to Rs.1500. About 100 of them were sold. it gave me nightmares. each board took an hour or more to fix. i decided not to do it at all. we rolled up the operations after a while. second time, fail.

by now, i had given up on doing anything with bitx boards. but a conversation with convinced me that SMD might be the way to go. we looked around and found a local SMD shop that agreed to do small runs for us. the smd components are much more expensive in india. we decided to keep the more expensive components like crystals, electrolytics in through hole format. i had to learn kicad. the women were now retrained to do the windings, insertion of through hole components and two rounds of testing. the component cost was at Rs.1500, another Rs.200 to the SMD insertion machine, Rs.200 for through hole insertion, testing. add another Rs.100 for packing and Rs.100 for local posting. we were selling these for Rs.2400 inside india and 45 dollars (a few hundred more to cover the additional expense of international postage) outside.

now, we come to the packing and shipping saga. the DHL/Speed Post quoted above Rs.1500 for shipping it internationally. that would be nearly 60% of the board’s sale price. instead, we looked at the ordinary postal service. so, we bought some amazon shipping cartons, assuming that these must be good enough for us as well and shipped some boards to friends around the world. we shipped five of them with the boards in bubble wrap. all fo them arrived in good shape. we rolled with this. WE USED BUBBLE WRAP. When we started actual shipping, we realized that the bubble wrap wouldn’t prevent the carton from collapsing. the coils were getting damaged. we needed some kind of a stiff roof over the board so the box’s sides wouldn’t collapse down. That’s when we started using the foam plate over the board. The foam provides a physical shield for the coils. The foam + the amazon cartons worked for a while. Then, we ran out of cartons.

Diwali is the christmas equivalent in India, the packing materials just disappeared from the market. we looked around and bought some other cardboard gift box. we sent them out as gifts to another set of people, they reported no problems, so we continued with those. after a while, we started getting complains about those boxes as well. then, we started looking around for something else.

we found these plastic boxes to be sturdy. we tossed them around, shipped them to a few volunteers around the globe and finally agreed that these were holding up. so we continued with these boxes. these boxes are costly. they are not ‘cheap’. i am personally averse to using plastic, but we thought that these were the best for the purpose. if anyone has a better idea, do test it out and let us know. we are always glad to accept anything better.
2.) Secondly, components and PCBs in the Indian market are generally available at a lower cost, sometimes much lower, than components purchased from prime US suppliers such as Mouser, Newark, etc. The US is one market, India is another. That’s the way it works. Components even cheaper than these: http://www.ebay.com/itm/Reel-O f-3000-MuRata-0-1uF-Multi-Laye r-Ceramic-Surface-Mount-Capaci tors-25V-X7R-/161765931843

we buy our toroids from w8diz. these are genuine micrometal parts. the pcb is of high quality made to ISO-9000 standards. we import components from mouser. the only thing that we do on the ‘cheap’ is that we use microprocessor grade crystals that we sort out manually.
What’s the current serial numbering up to as of December. Anyone know? It was #465 in early December. 465 units multiplied by $45 USD is about $21,000 USD. That converted to INR has the purchasing power in India of $70,000 USD here in the US. That’s a lot of bread.

we have shipped 1000 boards. we got 45,000 dollars in revenue and we have not yet recovered our expenses. i have provided you with the figures. add them up. as i said above there are far easier ways to follow to make money than bother with these boards. that’s why no one else is doing it. the design is in open source anyway.
What’s my point?

Seems like with that kind of wealth in play:

1.) The product could be double-boxed and well bubble-wrapped so it arrives undamaged after it’s 12,500+ km trip from Hyderabad. Old candy boxes or scraps of waste paper taped together just isn’t doing the job. Broken product means unhappy customers and a bad reputation.

as i said, bubble wrap didn’t work. there will be enough people here to vouch for that. we did try it.
2.) The single schematic that represents the functionality of the product could be up-to-date and error-free.

this is the schematic that was used to produce the PCB. where are the errors?
And for totally optional bonus points: A section by section Theory of Operation write-up that explains exactly how all the sections operate and how to troubleshoot. If a template is needed, look at vintage HP test instrument manuals or Heathkit ham radio transceiver manuals. Hint: Saying that, “It’s all been explained many times before on many forums, Google it.” does not get any points.

surely, it could be done. probably it is already done. bitx happens to be most well documented radio now. it is a community effort. look at http://golddredgervideo.com/kc0wox/ and soldersmoke and arv’s work and the large amount of stuff in the file section of the bitx group and you will realize that more people know, understand and write about bitx than a proprietory manual might contain. if you think it is lacking, go ahead and write some more documentation.

oh, btw, Ehsan is not an Ayn Rand supporter. He is a radically liberal guy who is more at home with the socialists at lamakaan than the suits of the software gang.
– f

Big News! BITX 40 Module Gets Digi Side Car! Raduino!

A very nice Christmas present from Farhan in Hyderabad! An Si5351/Arduino Nano VFO for the ALREADY AWESOME BITX 40 Module. I’m really glad Farhan kept the digital stuff on a separate board — it just seems like the right way to do it.

Details on http://hfsigs.com

SolderSmoke Podcast #192 FPM Rig, BITX Module Madness, HRO Al Fresco, Boatanchor Day, Mailbag


 SolderSmoke Podcast #192 is available:

http://soldersmoke.com/soldersmoke192.mp3

N6QW COMPLETING AN ORBIT TOMORROW!!!! Happy Birthday Pete!
Shortwave Woes: Deception and Disappointment!
Voice of Vietnam! But it is from Cyprus Creek S.C.
Radio Athmeeya Yatra in Punjabi! but it is in Nauen Germany. Yuck!
Sort of like these 9 cents per minute on-line relay ham stations. Yuck I say!
You know you are a hardcore homebrewer when a near empty can of Deoxit makes you nervous, so you order more, just in case.
Bench Reports:
Pete:
FPM FPM FPM!!! Tell us about it!
BITX 40 Module in Juliano Blue
Explaining the BITX 40 to the local club.
CULTURE SHOCK! Plug and play vs. Hardcore Homebrew.
Bill:
An EXTROVERTED BITX 40 Module
QRO with 24 volts on the Drain: 20 watts out. Heatsink upgrade, Chris KB4PBJ Thanks.
Analog Readout — Dymo tape and a Sharpie arrow
REVERSE POLARITY PROTECTION Where the perfect is the enemy of the good enough.
HRO no longer AL FRESCO Boxed up. Thanks Armand. Thanks Tim Sutton. Still working on AM receiver. Not inhaling very well.
Boatanchor Day: Fixed HT37 and hurt my back. Really. Got 160 meter station going. Changed ball bearings on CW key.
Next project. Another BITX 40, but perhaps for 160, 75 and 60 with Si5351 and plug-in filters.
Sideband History: THE SIDEBAND SUZY AWARD. Pete deserves this. I say we revive it.
LEX: Al Fresco. And Tim Walford calls them “Blackbox rigs” not “rice boxes”
HB2HB contacts. Often with guys who built their linear. I say that counts Too!
MAILBAG


The Nauen Transmitter Station (Germany)

There is a lot of radio history in this shortwave transmitting station. I came across it tonight with my BITX DIGI-TIA rig. It was on 7.215 MHz transmitting in Indian (South Asian) languages. But alas, the signals were not from distant India (home of the BITX!). Instead — as often happens these days — the signals were from a relay station. In this case they came from relatively nearby Germany, from the Nauen transmitter site.

Check out the Wikipedia page:

https://en.wikipedia.org/wiki/Nauen_Transmitter_Station

NO3M’s Amazing Homebrew 1934 Single Signal Superhet

Jim AB3CV reminded me this morning about the work of Eric NO3M. Jim was pointing out that breadboard construction need not be ugly and that Eric’s work is the proof of that. Indeed.
Almost one year ago, I worked Eric on 160 meters. He was using one of his beautiful breadboard rigs:
http://soldersmoke.blogspot.com/2016/01/happy-new-year-straignt-key-night-on.html
Jim’s reminder sent me once again to Eric’s site. I see he has been melting a lot of solder, and to very good effect. In just three weeks he built the magnificent 1934 QST “Single Signal Superhet” pictured here.
Eric has a great series of articles on this project, with excellent pictures and videos:
http://no3m.net/category/projects/
Bravo Eric!