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Saturday, April 30, 2016

KC9KEP's Superhet Receiver with HOMEBREW 455 kc IF Transformers



No store-bought 455 kc IF cans for Big Nick!  FB OM.  Great stuff.

We have featured Big Nick's beautiful work twice before:

More of his videos here:
Be sure to check out his coil winder.

Friday, April 29, 2016

Reduction Redux: Searching for Some Smooth Spin

OK, here is yet another picture of my Mighty Midget's Mate receiver, this time with yet another main tuning dial. I gave up on the large reduction drive on the right -- it worked fine but was very stiff.  I cracked open a smaller version of this very common Japanese-made reduction drive, but in this smaller one I was kind of surprised to find  a Jackson Brothers drive in there.   I now had three of these beauties available -- all of them worked fine but with considerable difference in ease of turning.  I picked the one that was easiest to turn.  

I had to cut the main shaft of the beautiful Hammarlund 35 pf variable cap that I am using. This was dangerous, because of the risk of messing up the delicate bearings.   I stayed out of trouble by putting the tip of the shaft in a vise and then cutting the shaft with a small coping saw.  This prevented any force from being transferred to the bearings.  It worked. 

I was careful to try to line up the shaft and the reduction drive as closely as I could. 

I needed something to serve as the tuning indicator.  I used one of those small CDs that often carry the drivers for cheap electronic devices.  It fit nicely.  A standard sized CD was too big. 

The final element was the knob itself.  I had an old Drake 2-B knob in my junk box (who sent me that?).  It was perfect and added a nice touch of soul to this old-new machine.

I built this receiver in 1998 and when I finished it I thought it was pretty good.  But it is much better now.  It has a nice 455 kc Toyo Crystal-Mechanical filter.  The tuning ranges on 40 and 75 now line up perfectly with the phone bands.  It now has a fuse in the power supply. And the tuning is now SMOOTH.

   

Tuesday, April 26, 2016

Always Listen to Pete! Second Thoughts on the S38-E


After working a bit on the Hallicrafters S38-E receiver, I am forced to admit that Pete was probably right about this receiver when he warned me that I'd be putting lipstick on a pig.  For those of you who have a sentimental attachment to this receiver, please don't take offense -- I understand.  But while I had one of these as a kid, I never really BONDED with it. That Drake 2B was stiff competition for my radio affection. So I can be more objective about this thing.  And I now think Pete was right. 

Problems: 

-- It is mechanically rickety.  It jiggles around mechanically and, as a result, electrically.

-- The front end is no match for Northern Virginia RFI.  All it has between the antenna and the converter tube is one puny LC circuit.  Not enough.

-- The LO mixer and the LO are stuffed into one 12BE6 tube.  The IF amp and the BFO cohabitate in another tube. In each case there  just seems to be too much going on between one plate and one cathode. 

-- The whole AC/DC transformer-less thing is kind of nuts. You have to get used to TWO ground symbols on the schematic: one symbolizes B- (and is not attached to the chassis).  The other is to chassis ground.  Turns out that my E model is not really a "widow maker" -- they have a 470K resistor and a cap between B- and chassis ground, so the damage you could do to yourself was quite limited.  Still, it is all kind of goofy.  I have an isolation transformer on the chassis, ready to move this receiver into the 1960s if the spirit ever moves me.  KB2WIG commented:  "At closing time, I don't care if the S38 has lipstick."  

As I worked on this thing, I began to realize that the little homebrew 6U8 receiver I have next to it on the bench is a much better receiver.  So I began to lose enthusiasm for putting lipstick on the S38-E.  At least for the moment.  I do like the cool 1950s place names on the S38-E's front panel:

Java
USSR
Vatican
Singapore
Edmonton (!)
Congo
Milan
Iceland
Angola
And of course, the CD (Civil Defense) frequencies. (For when you wanted to do some shortwave listening while ducking and covering. )

But for  now, me and the S38 are on a break. 

Saturday, April 23, 2016

A Reduction Drive for the Mighty Midget's Mate Receiver

This morning I put a reduction drive onto the main tuning cap of my 6U8 Mate for the Mighty Midget receiver.  Before I had been directly turning the 35 pf variable cap.   The tuning rate was a bit too high for easy tuning of SSB stations.  This drive went in nicely and it does reduce the tuning rate considerably, but it feels a bit tight.   Is there anyway to loosen up one of these drives?


Wednesday, April 20, 2016

Meeting up with ARRL CEO Tom Gallagher, NY2RF

On April 12, Tom Gallagher NY2RF was in DC and was kind enough to make some time in his schedule for us to get together and talk about radio.  As we mentioned on a recent podcast, Tom, who has recently taken over as Chief Executive Officer of the American Radio Relay League, is a true FB ham.  He has a restored Drake station that he keeps on the air, and was recently talking up the Michigan Mighty Mite during his interview with Eric 4Z1UG in the "QSO Today" podcast.  And he is a SolderSmoke listener.  It was great to finally meet Tom.  We are all lucky to have him at the ARRL.

Tuesday, April 19, 2016

Pigs, Lipstick, and my old Hallicrafters S38 "Widow Maker"


I blame Grayson for this.  After getting my old 6U8 superhet running nicely on 80 and 40, my attention turned to an old Hallicrafters S38-E that had been relegated to the car port (Armand saw it out there, looking abandoned.)  I didn't like it because of its "transformer-less" "widow-maker" power supply. I was afraid to even GIVE it away for fear that someone would electrocute themselves.  But Antique Electronics Supply had an isolation transformer, so the order went in.

I have to rewind or replace one of the primaries on the input antenna coil.  This was a victim of the original cheapo power supply.  Apparently the antenna terminal got grounded when the chassis was "hot."  POOF -- smoke was released.    

The bands do seem to sound better through thermatrons... And there is an undeniable 3-D aspect to working on these old rigs.

So yes, in a certain sense  REAL RADIOS GLOW IN THE DARK.

.............

Bill, I think that as long as you don't work on it in the car port in your bare feet you'll be fine!  Good luck with it and don't blame Grayson too much.  I think it was destined to come back in the house eventually.  The radio gods have been whispering in your ear!
 Ciao! & 73, Armand

............

Bill:
I’ll take the blame, no problem!
S38 is nice to work on, plenty of room, no magnifying glass required.  But I have to admit I am not a big fan of working on low cost AC line powered “raft-anchors” (too little for a boat).  Definitely give it a isolation xformer and replace the filter cap(s).  If it doesn’t weight 50+lbs, a bit lightweight for me.
If you need a good thermatron homebrew project (and who doesn’t really), I’ll send you plans for a nice 4-thermatron (including compactron) AM/CW 20/40M 5 watt transmitter I am finishing up (90% of the work is “finishing up”).   Designed from scratch.  Actually works.  Uses a new construction technique I’ve been working on. 
Grayson
..........

Hi Bill,
As I read about your next project – kept thinking –you can put lipstick on a pig BUT it is still a pig. I had one and put an isolation transformer on the front end –but found I was showing signs of carpal tunnel syndrome on my left hand as I kept retuning the radio because it drifted so much. Have fun.
Pete

Pete:
I don't know.  Simplicity is a virtue, and this thing is pretty simple: RF amp, mixer, LC oscillator, detector, audio amps.  Broad as a barn door with just two 455 kc IF transformers for the filter. Lots of room on the chassis. 
As for drift, my little 6u8 RX with LC oscillators in both LO and BFO settles down very nicely. 
Bill
...............

Hi Bill,
 I surely didn’t mean to denigrate your next homebrew project and perhaps it was that the one I had was a  dud in the lot.
 But I then moved up to the SX-99 and was in tall clover. Besides today we have some things we can do to enable “tamer” oscillators. So why not? You need to team that up with the M^3 and make some contacts.
 Pete
.............

Pete: I KNEW  you would try to get a synthesizer of some sort inside the S38-E.  But I say NO!  I had a lot of fun getting the LC oscillators in my 6U8 rig to tune exactly where I wanted them to tune.  You know, play around with the cap in series with the main tuning cap to change the tuning rate (better than removing plates -- they are hard to put back on!).  Then changing the values of the L and C elements to get the thing to oscillate in the desired range.  Then wrap it all up with some Dymo tape on the 1/2 CD "tuning dial."   Sure, I know, that would have been a few keystrokes on the Arduino, but somehow this old way puts you closer to the physics, closer to the electrons. Take a look at the e-mail about Wooden Boats, VFOs and PTOs on yesterday's SS blog. 

The "widow maker" potential of the S38-E was apparently on the minds of the guys who designed the cabinet. The whole box and the front panel are all very carefully insulated from the chassis.  Plastic nuts!

Nice looking pig, by the way.  She may appear on the blog soon. 

73  Bill



Monday, April 18, 2016

Wooden Boats, VFOs and PTOs -- Recovering Lost Arts

Sunday, April 17, 2016

K.P.S. Kang's Pixer Superhet



K.P.S. Kang (VU2KR and VU2OWF) has been contributing ideas and circuits for many years from his QTH in Punjab India.  He is the source of what became known as the VU Transmitter circuit:
http://www.zerobeat.net/g3ycc/week1.htm

Today I spotted a recent blog post by OM K.P.S. on a simple superhet receiver he is working on.  He has a knack for describing the design considerations (needed gain, IF selection, etc.)
Check it out:

http://smallwonderqrp.blogspot.com/2016/04/pixer-empirical-hf-superhet-receiver-i.html

and

https://plus.google.com/111066147552844651495/posts

Friday, April 15, 2016

WSPR Party Balloons Make it Across the Pond


   
Hans Summers
April 15 at 11:25am
 
VE3KCL/QRP Labs S-9 balloon finally reached Europe! What a crazy way to cross the Atlantic. Crossed Portugal, now into Spain. France is next! 16mW 30m WSPR signal was reported in ZL and VK (19,000km DX). Who says you need 5W on HF WSPR? 73 Hans G0UPL http://qrp-labs.com

Wednesday, April 13, 2016

VE3KCL Balloon makes "several loops around Greenland"

Oh, I really want to do this.  We had a bunch of balloons for my daughter's birthday and I found myself trying to guestimate how much they could lift.  There is a balloon store that sells the metalized party balloons used here.  They have a helium tank.   I hate to be a party pooper (!) but wouldn't the antenna represent a bit of a hazard?  If it came down in power lines, that wouldn't be good right?
In any case, three cheers for Dave VE3KCL and for Hans, G0UPL, the wizard who makes the QRSS/WSPR transmitter that is currently flying over Iceland.  

Hi all

Some of you must have seen this already - but the rest of you may find it interesting. Dave VE3KCL launched his S-9 balloon 4 days ago (2 standard party-balloons, hydrogen-filled) with modified QRP Labs Ultimate3S QRSS/WSPR transmitter onboard.

We are using WSPR messages for tracking - one normal WSPR message and one with a special data protocol to provide altitude, speed, Maidenhead 5/6th characters, battery voltage, temperature and GPS/satellite status. The transmitter has about 16mW power output, on 30m band. It is sending CW and JT9 as well. Altitude is a little over 10,000m. So far it has traveled in several loops around Greenland and the North Atlantic. Currently it is near the Faroe islands. See live tracking at QRP Labs website http://qrp-labs.com/ultimate3/ve3kcl-balloons/ve3kcl-s9.html

G-landers, don't get too excited that it appears to be heading your way - the wind prediction shows it likely to head back West almost as far as Newfoundland, before turning back East towards Spain!

73 Hans G0UPL

Tuesday, April 12, 2016

Some Thoughts on Noise and Receiver RF amplifiers from Scotland (and listening to sun noise on 2 meters!)

Bill,

Just listened to the latest SolderSmoke podcast where you asked why is it that an RF amplifier may be required on the higher bands but not on 40m and 80m for example.

At high frequencies the atmospheric and ionospheric noise levels are lower, so if noise figure of the receiver is reduced it will improve the signal to noise ratio you get from the receiver.  Adding gain -after- the mixer will not improve the noise figure of the receiver as it will be limited by the noise figure of the mixer. You need an RF amplifier which will itself have a lower noise figure than a mixer (certainly a passive mixer), to lower the total noise figure of the receiver to take advantage of the lower effective antenna noise temperature at higher frequencies.

This becomes very important at VHF and above, where antenna noise levels are much lower than at HF.

So, it isn't so much the overall gain of the receiver that is important with weak signal work, but the overall receiver noise figure which is determined to the largest degree by the first stage of the receiver.

There are spreadsheets available that will easily calculate the noise figure of cascaded receiver stages knowing the individual stage gains and noise figures.

One also has to be careful with the gain distribution throughout a receiver, if you have too much gain early on in an effort to improve the noise figure overall, you may overload the subsequent stages producing IMD with multiple strong signals. So there is a compromise to be met between noise figure and strong signal performance.

Going back to VHF and above if you have an antenna fed by coax with some appreciable loss then improving the receiver RF stage noise figure is not the best way to go because you are amplifying the signal after the loss the of the coax. What you need to do in those circumstances is to use a low noise masthead RF preamplifier which will give you gain and establish the noise figure of the receiver before the loss of the coax. Again there are spreadsheets to help with these calculations.

At VHF where an antenna is pointed at the horizon, the antenna sees the noise from the ground on the noise from the sky. As we elevate an antenna for EME or satellite working, then the effect of the ground noise should reduce (there will always be some due to side lobes) and then the receiver can benefit from even lower noise figure as the effective antenna noise temperature is now mostly determined by sky noise which at UHF is much lower than ground noise.

These last two days I have been able to see and hear the sun noise on my 2m receiver as the sun  set on my single 10 element yagi pointed at the horizon. Using WSJT's noise level scale I could see it  measure 12dB noise level and then once the sun set it dropped back to about 3dB noise indicated, most of that being local QRN from an antenna  sidelobe from my neighbour's house and his electronic devices which put out quite a bit of wideband noise on the band. (about 8dB above the lowest background level  I can normally detect).

To summarise, at LF where noise is high you don't gain anything by having a low noise figure receiver, and you actually lose out if you have too much gain early on as it will degrade strong signal handling.

At HF as manmade, atmospheric and galactic noise levels are lower, you can benefit from lower receiver noise figure and the way to lower your noise figure is to use lower noise amplifiers in the early stages of the receiver. Adding gain in later stages does not reduce the noise figure overall as the noise figure is largely determined by the first stage or stages.

At VHF using even lower noise figure devices in the RF stage will improve signal to noise.

Here is a practical test you can carry out. Switch between a dummy load and your antenna. If the background noise level increases when you switch to the antenna, then your receiver is sensitive enough, lower noise figure in the receiver isn't going to help.  If it doesn't increase then you have scope for improving the sensitivity of the receiver by reducing the noise figure of the receiver as you are no longer limited by antenna noise. 

Incidentally it is good to have a preamplifier that can be switched in an out of circuit so that you can reduce the noise figure when conditions allow ( low noise atmospheric noise levels for example), but switch it out if noise levels are high and signals are strong so that receiver overload and IMD don't occur. You can do something similar with an input attenuator to reduce strong signals where necessary.

I don't have a link here to the graph of manmade, atmospheric and cosmic noise levels versus frequency, but once you see one it becomes obvious why low noise figure receivers are not required at LF and MF generally.

73 from David GM4JJJ




Bill,

I found the article with graph of noise v frequency at last, in Ham Radio Magazine 1975!
A good read and as valid today as then.
I don't have a link here to the graph of manmade, atmospheric and cosmic noise levels versus frequency, but once you see one it becomes obvious why low noise figure receivers are not required at LF and MF generally.

73 from David GM4JJJ

Saturday, April 9, 2016

Soldersmoke Podcast #186 Is Available -- April 1 Rap Up, Pi Talk from Pete, Collins and Raspberries, Bill's Analog RX, Visits and Hamfests, MAILBAG

SolderSmoke podcast #186 is available:


-- April 1 WireWrapRap Rap-up.  Feedback from participants.

-- Bench Reports:
   - Pete talks about his Raspberry Pi SDR DSP rig.  
   - Bill talks about on his Mate for the Mighty Midget Receiver and his R2 Frankenstein.

-- A story from Pete's youth: Cruising the "Miracle Mile" with a Heathkit "Ten-er."

-- Why do we need more RF amplification (in receivers) on 20 than on 40?

-- Have you ever tuned the BFO freq in a superhet by the "sound of the noise?"  

-- A visit to Washington by Jonathan W0OX and family.

-- Bill goes to Winterfest Hamfest with Armand WA1UQO

-- Pete on the importance of balance (in life).

-- Great interviews on QSO Today: Peter Parker, Grayson Evans, and Ashhar Farhan.

-- MAILBAG:
- Paul Darlington M0XPD has a new book about life, travel, and the Dayton Hamvention.
- Michael AA1TJ QRV with a tuning fork at its 2,000th harmonic.
- Jonathan M0JGH living dangerously with homebrew QRP in Italy.
- Ben KC9DLM JoO with MMM
- Stefan DL1DF needs 3.579 MHz rock "with mojo." We have it for you OM.

The music for SolderSmoke 186 was written and performed (the bass lines) by Pete's son Tim.  Thanks Tim!
Pete also suggested that we have some rap lyrics for this music, so renaissance man that he is,  he composed some words. We are still looking for a performer.  

Yo we solder no more – its wire wrap and cables
The cables connect to the small  black box
hold on to your pants and pull up your socks
A cable goes here and a cable goes there
Turn on the switch and its Shazam all software



 





Friday, April 8, 2016

From Vietnam to Washington DC -- Jonathan-san KC7FYS W0XO 7J1AWL XV2OC Stops By With His AT3b

I first saw that QRP Altoid-tin ATS-3b rig  around 8 years ago in pictures that Jonathan-san sent from a beach in Vietnam.  He and his family were there on vacation from Japan.  (Included was a memorable picture of his young son in an NVA helmet.) During this time period Jonathan also tried (unsuccessfully, I'm afraid) to teach me how to properly pronounce the name of that famous electronics market in Japan.  

Jonathan and his family were in Washington yesterday and we got together for lunch.   It was great to finally meet them.  And to see that well-travelled ATS-3b.




Jonathan is a big fan of the ATS-3b, and for good reason.  A very neat rig.

Plug in filters for the ATS-3b.


Thursday, April 7, 2016

The meaning of "CM" in the Toyo CM-455 Filter

Photo by ZS1KE
A while back I picked up (from e-bay?) a 455 kc crystal filter for use in my Lew McCoy "Mate for the Mighty Midget" receiver.  I did a quick and dirty installation.  It kind of worked, but I had it in the back of my mind that I had to work on the impedance matching to ensure minimum passband ripple.  But when I learned what the P, B, E, and G pinout designations meant (plate, B+, earth and grid), I realized that this device had been designed with tube impedances in mind, so I probably didn't have to mess around with input and output networks (as I've done with the BITX rigs).  Last week I installed it as the manufacturer intended -- it sounds great.

Today I started wondering about the passband characteristics of the device.  What do the skirts look like?  So I started Googling.  There is not much out there, but I did come across a really interesting Epson site that describes the origins of this filter, and what the CM means.  CM is for "Crystal Mechanical."   Wow, this little box combines the characteristics of  a crystal filter AND a Collins Mechanical filter:

An excerpt:  
"While at the Electrical Communication Laboratory of NTTPC, Mr. Nakazawa had had a flash of inspiration: ‘We could develop a crystal unit with a high Q factor by using the wire mount technology I'm studying now. Then, if we can achieve the idea of a mechanical filter that mechanically joins multiple units using quartz material, we should be able to develop a compact filter that achieves both excellent filter characteristics and thermal characteristics.’ Without a pause, he quickly tackled the next development issue, which resulted in the creation of the ‘crystal mechanical filter (‘CM filter’)*5). This CM filter was manufactured by processing the quartz substrate into an ‘H’-shaped filter element and functioned by using the long thin sections on the left and right sides as resonators (Figure 1). The middle portion connecting the two sides fulfilled the role of the coupler. This was precisely the ‘mechanical filter achieved using crystal (quartz)’ that Mr. Nakazawa had envisioned.
This filter was released on the market as a 455kHz intermediate frequency (IF) filter for single-sideband (SSB) modulation in radio communications. The use of quartz material meant that not only were good filter characteristics achieved, but thermal characteristics were also excellent. As this was the first filter to offer properties of this caliber, it sold extremely well throughout the world. Furthermore, this technology received the honor of being granted the Notable Invention Award from the Science and Technology Agency."

Does anyone have the specs on these filters, and perhaps a passband graph?
Three cheers for Mr. Nakazawa!

Wednesday, April 6, 2016

The Wizard of Wimbledon writes of Emperor Hadrian's QTH, HMS Belfast, JFK and QRP

Dear Bill

I write this to you from my shack in Wimbledon, south west London, with the crackle of the bands slowly waking up across Europe, having just devoured the final few pages of your excellent Soldersmoke book; an intriguing and entertaining tale to which many of us can relate, a highly-accessible technical primer which certainly helped me to clarify a few niggling “Yes, but why?” questions, and a compendium of handy tricks to try during future projects – thank you for sharing your story.

I was amused to read that GB2RN, on HMS Belfast in London, where I am now one of the “new boy” volunteers, was an inaugural contact for your Azorean 17m DSB rig. As it turns out, 12000 tonnes of British warship seems to play an crucial role in testing QRP radios:


Enjoying a peaceful hilltop picnic in December 2014 with my girlfriend, gazing out over the idyllic Italian countryside above Frascati, it occurred to me that what the situation really called for was a 40m QRP CW transceiver (I was possibly alone in this thought). Soon after returning home I set about researching small, reliable kits which could slip into my jacket pocket but still tune across the band.

The EGV-40 (in memory of Miguel EA3EGV, EA-QRP co-founder) seemed ideal: a “tutti frutti” architecture of well-proven designs, based around a VXO for high stability.

My construction schedule was leisurely, paced for enjoyment and attention to detail. At all times I looked to maximise reliability, crucial when operating from a hilltop, far from a workbench. To pre-harmonise the radio with an outdoor life, on sunnier occasions I often found myself soldering in the garden. For a personal touch, I made sure to instill plenty of “soul”, reminiscent of my electronics journey so far: my late grandfather's tools and solder were used throughout, alongside my own, together with reclaimed parts from old school projects and my elmer’s junk box; finally, in a shameless attempt at appeasement, my remarkably understanding girlfriend even helped to solder the final capacitor… and may be invited to recommend the paint colour!

In mid-December 2015 we once again flew out to Rome for our pre-Christmas break. Our first day was spent exploring the stunning Villa D'Este (stunning to behold, an ideal high radio QTH but far too beautiful for my wires to pollute the scenery without getting into trouble...) and Villa Adriana, near Tivoli. It was only right at the end of the afternoon, and annoyingly lower down towards the plains, when I stopped for a few minutes for an attempted sked with GB2RN.

Lesson 1: trees with lots of branches and twigs are a real pain for throwing wires through! I had guessed this already, but it truly is an exponential problem. 

After conquering a geometric puzzle, I had my EFHW strung so that the point of maximum radiation was about 4m in the air – not exactly ideal for DX but theoretically reasonable for a nice high angle of radiation, like I needed. The feed point (fortunately a current null) was at roughly half this… time to get on the air!

Lesson 2: when operating outdoors – beware of the locals!

Rather than a comfortable bench I resorted to operating whilst sitting cross-legged on the grass, balancing my ex-German military miniature key on my thigh as I tapped it with my finger and attempted to steady it with my left hand. 

The ambient sound of the 40m band seemed very different in I-land – that was the busiest I'd heard it outside of contests, riddled with deafening Eastern-bloc calls but not a single station from any of the British nations, which I presume must have largely been in the shade of the skip; apart from booming GB2RN beaconing to me high on the band :-)

The Villa closes at 1700 and from past experience the wardens come around at 1630 to chase stragglers out from the far corners. Annoyingly one such woman decided that my guy wire and its supporting tent peg looked highly out of place and must be interfered with. My Italian is woefully incompetent at the best of times, so I resorted to gesticulating at her wildly with my left hand as my right attempted to stay faithful to sending clear CW.

Perhaps it was for the best; had she understood that I was “Making a scheduled contact with a British warship via Morse code using home-built equipment which I had smuggled into the country by air last night", the tale might have taken an entirely different twist...

Cold hands, fading light and a dead leg from sitting in an awkward cross-legged position which is frankly impractical for anybody beyond the age of 8, but I was utterly thrilled to have enjoyed my first QSO from overseas, and particularly so since it was with my Elmer on the ship using a station which I had diligently put together myself over a number of months.

The first wisps of solder smoke have already left my iron this morning as I embark on the next stage of my QRP apprenticeship – to make the jump from a kit operator to a scratch-built home brew. All my life I have yearned to understand from first principles, and our remarkable hobby offers us a unique privilege to do so whilst sharing experience along the way.



Our objectives are decidedly more modest in scale, but I’m often reminded of President Kennedy’s famous quote: "We choose to go to the Moon in this decade and do the other things, not because they are easy, but because they are hard”.

72/3

Jonathan
M0JGH

PS Should you or any of the Soldersmoke brotherhood ever be in London and wish to operate from GB2RN, please don’t hesitate to contact me.



Tuesday, April 5, 2016

My Mate for the Mighty Midget Thermatron Receiver



A few days ago I received an e-mail from Jan PA3GSV -- Jan is working on a receiver similar to my old Mate for the Might Midget and had some questions about how I'd handled the filter portion of the circuit.  Then on Sunday, while listening to Eric's interview with Farhan on the QSO Today podcast, I got so enthused that I felt compelled to work on a homebrew receiver.   So out came the old Mate for the Mighty Midget.  I built this thing in 1997-1998.  It is described here:

In the above  video  I was listening on 75 meters to a very congenial early morning roundtable featuring W4CH, K5KBZ and others.  I know, I know, this is the third or fourth video that I've made of this thing.   This is almost as bad as 2B-mania. Or the Michigan Mighty Mite thing.   I blame Jan.  And Eric.  And Farhan.  And Grayson.  And Lew McCoy!

Here is my e-mail exchange with Jan:

Bill:
I recently build the W1TS two tube xtal controlled transmitter, and am looking for a 80/40m companion for this that has a crystal filter.
At first, I wanted to build the “Simplex Super” and finally got hold of the 1700 kc crystals, but then they got lost in the mail…
Only part of a two box shipment arrived, with 455 kc fundamental frequency FT-241 crystals, so now I am looking for a diagram using a 455 kc IF. Jan

Jan:   In this link you will find the schematic for the receiver I built. 

 I was not able to build the filter with the two 455 kc crystals.  I could not obtain the needed crystals.  I used two 455 kc IF transformers as described in my article.   This resulted in a very broad frequency response but it was OK and quite good for AM. 
 Last year I put in a Toyo 455 kc SSB filter, but I did not match the impedances, so the results were not good.  Your e-mail makes me want to work on this again! 
 Let me know how your receiver turns out. 
 73  Bill  N2CQR

Thanks for your reply.
It is a neat looking little receiver.
And yes, I also have a cardboard box labeled “good junk” which is filled with stuff from ham fests J
Finally it will be put to good use!
I printed the article for some evening reading this week.
It will take me some time building this receiver, as there is some metalwork and mechanics involved.
I will let you know how the receiver turns out, and I am also curious what improvements you make on yours.
 Thanks again, and I will let you know.
 73  Jan PA3GSV

Wow, Jan has the Knack!   Check out his station:



That's the W1TS rig on the left.  More pictures from Jan on his QRZ.com site.  He too uses wood cabinets!  I'm not alone!  Here's Jan, PA3GSV








 


Monday, April 4, 2016

April 1 and WireWrapRap: How to Calculate Your Score

Let's make it official:
APRIL FOOL!

Even though "more involvement in contesting" was just another part of our WireWrapRap hoax, I thought it would be appropriate to offer a scoring scheme for those who participated in our little April 1 special event.  Just answer the following questions and keep track of how many points you earn for each:

When you read the WireWrapRap April 1 blog post, how many paragraphs did you read through before you knew it was an April Fool's Day joke? (Maximum 12 points.  If you knew it was a joke as soon as you read the title, award yourself ZERO points.)

When you read the WireWrapRap April 1 blog post,  were you at any point further convinced of its authenticity by the fact that the title of the blog had been changed?  If so, award yourself 2 points.

If after reading the WireWrapRap April 1 blog post you Googled "Wire Wrap," award yourself 5 points.  Award 15 more points if you even briefly thought that this might be a nice alternative to soldering.

When you read the section about the digital modes, did you at any point question the existence of the "new" SNICKR, Oreo, and Oregano modes?   If not, award yourself 5 points.

After reading the WireWrapRap April 1 blog post, did you  -- in an effort to confirm your suspicions -- go to  the comment section to see if others had declared it an April Fool's joke?  If so, award yourself 10 points.  (Be honest here guys.  We got 41 comments on this post, a new record for the SolderSmoke blog.  For some reason a lot of people were checking the comments section.  I'm just sayin...)  

If, after reading the WireWrapRap April 1 blog post you felt anger toward the author for the way he had so selfishly and greedily abandoned the cause of analog, discrete component, Hardware Defined, axial lead electronics, award yourself 5 points.

If, when you noticed that MANY  of the comments on the April 1 blog post had been "removed by the blog administrator," you assumed they were obscene, irate, or perhaps (justified?)  threats, award yourself 15 points. (In fact they all said "APRIL FOOL!" and were removed so that they wouldn't spoil the fun for late arrivals.)  

If one of your comments was among those "removed by the blog administrator"  award yourself NEGATIVE 5 points. 

If your anger about the changes being announced to the SolderSmoke podcast led you to send a complaining or threatening e-mail (or text or tweet!),  go ahead and award yourself 10 points (and please consider enrolling in an anger management program).

If,  on the other hand, after reading the WireWrapRap April 1 blog post you actually sent us an e-mail, comment, text, or tweet congratulating us or wishing us well on the new WireWrapRap podcast, award yourself a richly deserved 25 points. And thanks for the kind wishes.

If this scoring scheme is making you angry now, award yourself 5 points and seriously consider the anger management thing.

If, after reading the WireWrapRap April 1 blog post you actually tried to find out how to get the new podcast from Soundcloud,  award yourself 25 points.

Please send me your scores.  You can put them in the comments section (and I know you know how to do this).  Or you can e-mail them to soldersmoke@yahoo.com.   Or you can text them or tweet them to us or send them to the Soundcloud (just kidding).  Don't worry, we probably won't be announcing the winner.

Sunday, April 3, 2016

Possibly the Best Ham Radio Interview Ever: Farhan on "QSO Today"



Stop what you are doing.  Run -- don't walk -- to the "QSO Today" website of Eric Guth 4Z1UG.   There you will find his interview with Ashhar Farhan VU2ESE

There is so much great information, inspiration and wisdom in this interview.  I was so captivated by it that -- even with the availability of the pause button -- I was unable stop listening even for the time it would take to walk to the kitchen to refill my coffee cup.  But at the same time, listening to Farhan describe the joy of bringing a new receiver into operation compelled me to go over to the bench -- in mid-podcast -- to tweak a receiver that I am working on.

In this podcast you will hear about how Farhan got started in ham radio, about his Elmers about the origins of the BITX, about the Minima and the new HF-1 rig, about Farhan's spectrum analyzer project and about a new goodwill effort to send BITX circuitry to aspiring hams around the world, especially in developing countries.

Throughout you will hear Farhan speak of the importance of the book, Experimental Methods in RF Design. 

I really do think this is the best ham radio interview I have ever heard.  Congratulations and thanks to Eric and Farhan.

Here is the link:

Friday, April 1, 2016

A Major Change For SolderSmoke: Introducing the WireWrapRap Podcast!


A New Direction for SolderSmoke
Introducing Our New Podcast:  “WireWrapRap”


Attentive listeners have probably noticed that for some time now the podcast has been drifting in a new direction.  Some have been concerned by this change.  I myself, as you know, have shared in many of these misgivings.   But I have become convinced that it is time for a major change in direction.  We've been doing this for more than ten years -- we are one of the oldest ham radio podcasts.  It is time for a change.
A number of people have encouraged me to make to this change.   My co-host Pete Juliano N6QW is clearly the main influence.  Pete has made me see the errors of my Ludite ways.  He taught me that it is time to put away the Dymo tape and get with it with glowing numerals.  Whenever I started getting enthused about VXOs or about Permeability Tuned Oscillators using brass screws moving through hand-wound coils, Pete was there to remind me of the beauty, simplicity, and efficiency of Arduino Microcontrollers and Si5351 chips.   Paul Darlington M0XPD contributed an element of old world legitimacy to this push for modernity. Tom Hall AK2B was another influence -- whenever I was on the verge of quitting, he’d Skype in from the Big Apple and get me back on the digital track.  And we can’t forget Farhan over in India – as soon as he started putting Arduinos and Si570s in his Minima, I knew this was really, as the kids say, “a thing.”
So anyway, it is time for a change.    I know many of you may find this shocking, so it is probably best for me to just go ahead and say it:  We are changing the name of the podcast and we are changing its focus.
n  Instead of SolderSmoke, the new name will be “WireWrapRap.”   Wire wrap is the solder-less wiring technique often used in computer circuitry.  We hope that the “Rap” thing will be especially helpful in attracting young people – especially those Maker Millennials -- to the show.  And, you know, soldering just seems so 20th century.     

n  Instead of traditional homebrew radio, the show will be focused on Mini Computers (especially the Raspberry Pi), Software Defined Radio, Digital Signal Processing, Microcontrollers (especially the Arduino), and the use of smart phones in ham radio
n  Obviously this implies a move away from minimalist radio and QRP.  So yes, we are going maximalist and we are going QRO. And we are getting more involved in contesting (see below).  

Now I know what some of you are thinking – that this must be part of our long-standing quest for sponsorship and that this is all about money.  But that’s only part of it.  Yes, we have secured a lucrative sponsorship arrangement with a company involved in microcontrollers, small computers and smart phones that is focused on the millennial market.  But we’re really doing this for the good of our listeners. 
Don’t worry, you will find many of your favorite parts of SolderSmoke in the new show.  They will be the same, only different.   For example, instead of the “Bandsweep” segments that we used to do, now we are going to have “Codesweep”  (and it’s not about Morse).  Where we used to have SolderSmoke Mailbag, well, don’t worry -- we are going to continue to have a segment that will allow for listener input.  We going to call it “Pi Hole.”  We’ll only be accepting listener input via TEXT messages or Tweets – we are, after all, trying to be modern.  Along the same lines, we will be distributing the podcast exclusively via Soundcloud.  So get with it gentlemen! Get into the cloud!
In the new and improved podcast we want to explore the new and exciting digital modes.  We plan segments on all the new ones: PSK-99, Opera, WSPR, SNICKR, Throb, Thor, Piccolo, Oreo, Oregano,  you know, all those weird sounds you’ve been hearing near what used to be considered the CW portion of the band.  It will be such fun!  I can’t wait to decode some Oregano!
Smart phones, are, of course, the future of ham radio, and we intend to be fully into those little magic boxes.  I don’t know if you guys realize it, but all of that ugly dusty junk in your shack can be replaced by a few lines of code from the App Store.  That room you used to call “the shack” can be converted into the Yoga studio or knitting room that your wife has been longing for!  Now you can carry your station with you wherever you go and autonomously participate in contests from stations around the world.  Imagine the thrill of learning that while you were playing golf or bowling, you were also WINNING a major DX contest from a “station” in Ulan Bator. And that ALL of your reports were 59!   It’s like owning your own ham radio drone!  Congrats old man.  YOU WON! Welcome to the 21st century! That’s the kind of operation we are going to explore on WireWrapRap!
For those of you who are worrying that we might be abandoning our microphones, have no fear my friends, Pete and I remain committed phone operators. Only now, it will be DIGITAL VOICE.   We’ll be squeezing our dulcet tones into a mere 800 Hz of bandwidth.  This way we both sound exactly the same.  Heck with this new technology everybody will sounds the same.  How cool is that!   We’ll all sound like a mix of Stephen Hawking’s synthesizer, Apple’s Siri, and MTV's Max Headroom.   The AM guys and the Enhanced SSB crew may need some time to get used to this, but c’mon fellas, it is time to get with it!  There will be no more need to tweak all those menus for “presence” and “brightness” and “mid-range.”   Heck no, we’ll all sound the same!  Progress my friends, PROGRESS!
As I said, I had my doubts about this.  But over the weekend I walked into the TV room and Elisa happened to be watching one of those “inspirational self-help” speakers on Direct TV, and you know what?  He made a lot of sense. Change IS good!  We have to EMBRACE the future!  Impossible = “I’m possible!”  Yea!  So thank you Deepak Chopra!  Thank you Pete Juliano!  And welcome --  all of you -- to the WireWrapRap!
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