Dave Richards AA7EE

June 29, 2011

Order From Dan’s Small Parts And Kits Arrives

Filed under: Uncategorized — AA7EE @ 9:29 pm
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Of all the orders for electronic parts that I’ve placed in the last couple of weeks, the one that I have been eagerly awaiting the most was the one from Dan’s Small Parts And Kits. It was also the one that I haven’t really been counting the days on because even though I haven’t used Dan before, I figured the turnaround wouldn’t be that swift.  Firstly, you can’t place orders directly from his site – you have to write them down or print them out and mail the piece of paper to him (or print out a form from his site and use that). Secondly, his mailing address is a PO Box so unless he checks it every day, that’s a second factor to delay the whole process.

If your order is over $75 and you pay with a USPS money order, the shipping and insurance are free, so I took that option.

Here’s the timeline – mailed the order Friday June 17th certified mail (the order was for over $200, paid with a money order, and the first time I’d used him)

– it arrived at Dan’s PO Box Wed June 22nd and a notice left in his box

– he signed for it Saturday June 25th

– I received the package from him via USPS Priority Mail today, Wednesday June 29th

I do wish he’d accept orders directly from his site – or at least accept orders via e-mail with Payment via Paypal. That would have cut a week from my wait but it’s OK – I knew this going in. Once he received my order, he was fast turning it around.

Here’s what I got. A well-packed box full of fixed and trimmer caps, pots and trimpots, transistors (bipolar and Jfet), IC’s, voltage regulators, slide and toggle switches, PC board pieces,  magnet and hook-up wire, heatsinks, crystal sockets,  diodes (germanium and silicon, varactors,  ADE-1 DBM packages, inductors, in other words, a veritable cornucopia of goodies for any home-brewer.  My kitty was asleep just a foot or two from this treasure trove and luckily she didn’t wake up, or she would have had a field day with this lot:

I’m particularly fascinated by this 15-365pF Sprague Goodman trimmer, of which I ordered 5.  It’s substantially large:

I’m planning on using it as a bandsetting capacitor for a regenerative receiver, with the main tuning being done by a varicap and pot. That way, I can build a regen for the SW bands, and choose to operate it on any one of several small chunks of spectrum in the HF region. I think I also bought it because I’ve never had a trimmer cap so big – one of the fun things about putting in big orders for parts.

Combined with the toroid cores, other transistors and various other bits I have here (including hundreds of resistors in all the popular values), and a couple hundred circular Manhattan pads I made a few days ago, if I can’t build something from this little collection of beauties, I might as well take up collecting Victorian thimbles – and I’m not about to do that 🙂

The parts from Dan smell mildly of tobacco smoke. While some folk might not be too keen, this was very evocative of my early years getting interested in electronics as a kid.  The Principal and custodian of the elementary school I attended in England were both very interested in building electronic gadgets and were both role models to me.  I remember Mr Fitzgerald’s office (he was the custodian) being packed full of circuits that he’d built and other electronic paraphernalia. Mr Donegan, the principal, was friends with Mr Fitzgerald, based on this common interest, I assumed.  Mr Donegan lived in the same village as me, and I used to go to his house and knock on his door just hoping to see the latest gadget he’d built.  Poor guy, being hounded by his pupils at home. One gadget he’d built that I particularly liked, was a “Burp Box”. It was 3 audio oscillator circuits built with BC109 transistors. The oscillators were linked to each other somehow, so that when you adjusted the pots that controlled the frequency of each oscillator, it somehow modulated the other oscillators.  The result was all kinds of cool sound effects that were hard, if not impossible, to duplicate. I tried to build my own, but it didn’t work very well. One day,  Mr Donegan came to his door, handed me the Burp Box that he had built, with the words “Here you are – one Burp Box for one good boy” and very kindly told me it would be best if I didn’t bother him at home anymore. I don’t remember how he worded it, but I was so excited about being given his Burp Box that I didn’t mind one bit.  I cannot remember whether it was Mr Donegan or Mr Gerald Fitzpatrick that smoked. Maybe neither of them did, but for some reason, the combination of electronic parts and the smell of tobacco smoke is quite evocative of childhood to me.

A few of the parts from Dan’s do look rather old, but many of them don’t, and I suspect that the overwhelming majority of will be perfectly serviceable.

In short – a big vote for Dan’s Small Parts And Kits.

Now where’s my soldering iron……………

June 28, 2011

My Morning – QRS Pse OM and G4ILO News

Filed under: Amateur Radio,Ham Radio,QRP — AA7EE @ 2:12 pm
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My morning began quite well. I woke up at about 3:30am and heard the Russian “K” beacon on 7039.3, tuned lower down the band and worked JS1NDM – Hiro near Tokyo.  Worked him with 4W from my Norcal 2N2/40.  From his QRZ listing, it looks like he has a beam on a tower, and was probably running quite a bit more power than me, so thanks Hiro for doing the heavy lifting in our QSO.

Just now, about 6:30am, 40 is only open for relatively local QSO’s. I called CQ on 7030 at about 15 wpm, sending the characters at 17 wpm, but with the spacing at about 15 wpm – it’s the way I normally send.  A station, who sounded like he was sending at about 5 wpm asked me to QRS, which I did.  We couldn’t complete a QSO, due to QRM, QRN and QSB at his end (what a deadly trio!) I also had great trouble copying him, but it wasn’t due to QRM, QRN or QSB.  It wasn’t even due to the spacing between his words;  it was due to the speed at which he was sending his characters.

I learned Morse code by using some version of the Farnsworth Method, learning the sound of each letter with the characters sent at a speed of somewhere around 15-20 wpm, but with longer spaces between them. Then to speed up my copying, all I had to do was close the gaps between the characters, because I already knew what each of them sounded like.  When you learn the code with the letters sent at a very slow speed, you don’t instinctively learn the sound of each letter. I’m pretty sure that was how the station who asked me to QRS this morning had learned the code.

The thing was, was that even though I was really concentrating hard, I couldn’t copy his sending, because his characters were all sent slowly.  In order to copy that slow, I have to think in terms of the letter “A” being a short one and a long one, and “B” being a long one and three short ones. It’s a whole different code.  If he had sent the characters at 12wpm or greater, with big spaces between them, I could have copied, but the way he was sending, I just couldn’t do it, no matter how hard I tried.

When you are learning code, please, please, learn the letters as complete sounds. It makes it a lot easier for you to eventually increase your speed, and a whole lot easier for other stations to QRS for you.  I am very grateful to the superbly competent higer speed ops who slow down for me.  I really want to be able to do it for others, but I can only do it if you send the letters as complete sounds at a speed of, say 10wpm or up – even if the gaps between letters are long.

I do hope this doesn’t come across as unhelpful of me, but it is genuinely intended to be the reverse.

On a different note, Julian G4ILO has just received some worrying news about his health, which he has related in his most recent blog post. I’ve been following his amateur radio blog for years and had to do a double-take when reading the post; I couldn’t quite believe what I was reading. He has a big following online, and I know that all his readers wish him and his XYL Olga the very warmest of wishes in dealing with his health issues. Of course, we are all eagerly awaiting his return to blogging. Julian has published his address on his blog and I’m sure he’d welcome a QSL card or other communication in the mail. At times like this it’s good to know that others are rooting for you. Let’s fill his mailbox with good wishes!

June 27, 2011

The N3ZI Digital Dial

The last 2 QRP radios I built were the Fort Tuthill 80 and the Norcal 2N2/40, both of which I fitted with KD1JV digital dials. I’d seen Doug Pongrance N3ZI’s Digital Dial and was curious, as it drives an LCD display, as opposed to the LED display in Steve Weber’s kit. I figured that it should draw less current and as such, would work well for QRP rigs operating from battery power. That wasn’t quite what I found, though the N3ZI Digital Dial does have other advantages.

The counter comes as the PCB and a small bag of parts packed in a small box.  Doug does sell a serial LCD display to go with the counter, but there are many cheap displays sold on eBay that will also work with this counter. I chose to go the latter route, as I wanted a display that was the same size as the counter board, and Doug’s display is much longer. When ordering the counter kit, you can also order a hardware kit to fix the display to the counter board, if you’re going to use a display of the same size. There are full details at N3ZI’s site that explain what types of LCD his two boards (the full kit and the super kit) will drive.

I bought a nice display with yellow backlight from a vendor on eBay called electronics_lee for $4.80 including shipping from China. Even better, was that instead of the 3 week timeline that eBay gave me for delivery, the display was in my mailbox in just 6 days (5 business days) from the date of ordering from China – and all for $4.80 including shipping from China. Actually, Doug’s LCD is cheap also, it was just that I wanted a smaller one.

It goes together easily, and here’s what the whole thing looks like. In this first shot, you see more of the display I bought from eBay than the N3ZI board:

Here’s the flip-side, showing the counter board. If you want a lower profile, you can mount some of the components on the other side of the board, and mount the crystal horizontally. I just built it “stock”.  Visible are the 2 micro switches that are used to program the IF offsets into the board (it can accommodate up to 9) and to select them when the dial is in use. On the right at the front is the trimmer pot for varying LCD contrast, on the right-hand side near the back is the (black) power jack, and behind the regulator is the signal input jack (white and partially obscured by the regulator):

In this shot you can clearly see the short wires I used to connect the 2 boards.  You can use header pins and a ribbon cable if you want, but this seemed unnecessary, as I don’t expect to be disconnecting and reconnecting the display.  One thing that did offend my slightly OCD sensibilities was that the insulation on the wires I used melted readily when exposed to heat, and you can see the result.  Aaah well, I have to learn to control my inner desire for perfection, or I’ll never get any experimentation accomplished:

Compared to the KD1JV Digital Dial, which is a favorite for many QRP’ers wanting to add a frequency display to their radios, it is quite large. Here’s a comparison shot of the N3ZI counter on top of my Fort Tuthill 80 fitted with the KD1JV Digital Dial:

The full counter kit from N3ZI can supply current for a backlit LCD as well supplying either a +ve or -ve voltage for the display contrast (some LCD’s require a -ve voltage). It’s pretty much a full-service kit to drive most LCD’s. Add to that the fact that you can program in up to 9 different IF offsets including an offset of zero for use as a straight frequency counter, and you have quite a versatile counter for the shack.Two things that I like about the N3ZI counter are

1)        The IF offsets are programmed in manually using the switches – you don’t have to feed it a squirt of RF. You can do this with up to 9 different IF offsets and,

2)        Instead of a trimmer capacitor to fine-adjust the crystal for optimum accuracy, you can calibrate the counter in software using the micro switches.

Comparing KD1JV’s Dial with the N3ZI one again, I measured a current draw of only 20mA on the dials in both my Norcal 2N2/40 Tut80), and with the LED display switched off, which is achieved by holding the control button down for a little over a second, the consumption was just 7mA for both units.  My N3ZI Dial consumed about 34mA with backlight and 18mA without.  The backlight on the display was quite bright, so I increased the value of R3 (the resistor on the N3ZI board that supplies the backlight current) to 100 ohms whereupon the current consumption decreased a little to 28mA with little noticeable decrease in the the brightness of the backlight. All the preceding current consumption measurements for both units were made at a supply voltage of 13.8V.

So what’s the upshot of all this? Well, current consumption differences (which are minimal) aside, I see these main differences:

Programmability – in order to program an IF offset into the KD1JV Digital Dial, you have to feed it with RF at that particular frequency while the counter is in program mode. To program it with a different offset, you would have to follow this procedure again.  You can program an offset into the N3ZI Digital Dial directly with the micro switches, and can do this for up to 9 different offsets, all of which can be selected by the micro switches during use. If you mount the dial in a case, panel mounted buttons can be employed

Size – if space is at a premium, the KD1JV Dial is the one to go with. N3ZI’s counter does take up more space, though it offers more features (albeit with a little more current consumption if you’re using a backlight)

Anti-jitter – The N3ZI Digital dial contains anti-jitter code so that the last numeral doesn’t constantly flicker between 2 adjacent digits, which the KD1JV dials sometimes does

As for me, I’m leaving the KD1JV Dials in my 2 rigs – they’re small and the current consumption is low, but am pleased as punch with the N3ZI Dial as a general counter and digital dial for the shack.

NB – In it’s standard configuration, the N3ZI Digital dial covers 1 – 45MHz but the coverage can be extended above and below that by changing a jumper on the board.

EDIT – I just received this e-mail from Doug N3ZI with some useful information on his counter:

Thank you for the unbiased review and positive comments.

I do have some comments regarding power consumption.  You reported 18mA,  I would expect a few mA less.  But it depends on exactly what VFO  frequency is input, and exactly what LCD is being used.   But one can get much lower power, ~5mA, by powering it off of a 3.3v battery, rather  than the 5v regulator, and without a prescaler.  It will count up to about 8.5MHz in this configuration so it’s OK for a 80M or 40M DC radio.

The micro just checks the frequency occasionally, and if it’s the same as the last reading, it goes to sleep without updating the LCD.  The micro draws about 40% extra power for a few seconds after power up, and
for a few ms when the frequency changes.  But if the prescaler (divider) chip is used and connected to the radios VFO, it will run all the time,  and thus continuously draw 1-3mA depending on the VFO frequency.

If someone is looking for a low power backlit display, the Blue/White ones being sold on ebay are very readable with backlight currents in the 5-10mA range.  And there are some much smaller LCD available in the 8×2
format.

Again, thanks for your report.

73, Doug, N3ZI
http://www.pongrance.com/

June 19, 2011

No Commercial Rig In The Shack For Now And All Sorts Of Homebrew Plans

Filed under: Ham Radio,QRP — AA7EE @ 3:55 am
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I sold my FT-817 just days after mentioning 2 posts ago that it was up for sale.  After a week on Craigslist, I was planning on putting it up in a few of the online ham forums and then on eBay. It didn’t come to that though. In fact my rig sold not because of Craiglist, but because of the post here on WordPress.  I didn’t know that many folk read this blog!  Shortly after posting here that the 817 was for sale and including a link to the Craiglist ad, I received a call from Frank KA8SYV, saying that he was interested, and courtesy of Paypal and Fedex, the deal was finalized. I’d assumed that he found me on Craigslist but then remembered a remark he’d made during the phone call in which he complimented my large CD collection. The only way he could have known about that was if he’d seen this blog first before following the link to the Craigslist ad to get my phone number.  Hope that’s not against WordPress rules 🙂

The day that Frank received the radio, he called to let me know, and we had a great conversation. Frank’s been getting back into the hobby in the last couple of years, and his enthusiasm is infectious.  He told me about a great little 80M indoor loop that he built (which he forwarded details on) and it turns out that he has the kit to build K8IQY’s SS-40 receiver.  I’m envious, as I have really enjoyed the receiver on Jim’s 2N2 transceiver and the SS-40 is also reported to be low-noise. It was just great to converse with a fellow ham who has similar interests to mine – thanks for the phone QSO Frank.  I knew that Frank would be a trustworthy buyer – not only is he a fellow ham who can build things, but he also has a picture of a kitty in an astronaut suit on his QRZ page.  He just had to be cool!

As a result of that sale, the band coverage here in the shack is a little slim, but that’s fine by me.  I have the Tut80 on 80M, the Norcal 2N2 on 40M, and NT7s’ VRX-1 direct conversion receiver – also on 40M. My 80M activity is sparse, due partially to the fact that my only antenna is a co-ax fed inverted vee for 40, so 99.5% of my activity is on 40M CW.  Most amateurs would consider this a very meager ham-shack situation, but it’s working out well.  I never have to try and figure out which band to operate on, and I spend zero time adjusting the ATU. The 2N2 is always on so when I want to operate, I just turn the volume up on the rig.  Also, the lack of a commercial transceiver is a very good incentive for me to build equipment for the other bands.  I like what not having ready-built gear does for my creative juices.  If I want to go on 20, I have to sit down and figure out what to build for that band, as I’m not about to buy another commercial rig just yet.

The plan here at AA7EE is to spend more time building and experimenting.  I don’t design circuits, but I have enough gumption to build from schematics, and have been wanting to get lots of practice in Manhattan construction for a long time now, so the plan going forward is to build stuff. With that in mind, I spent a day or two putting in a big order with Dan’s Small Parts And Kits, as well as a small order for toroids and some transistors from W8DIZ –  “The Toroid King” (how can you say no to 50 x 2N3904’s or 2N3906’s for $3?)  The goal is to have a big stock of the most commonly used components, as well as enough PCB material to make Manhattan pads and build cases. Once I have a well-stocked junk-box, I can see what I’m using from it and order ahead to keep it stocked up. Hopefully, most projects will only require me to order just a few parts, with the rest coming from the personal stash of parts.  As a kid I had a big junk-box of parts, but it consisted mainly of donations from local and benevolent hams with the contents of a few self-purchased “grab bags” thrown in. I’ve never purposely ordered bulk amounts of all the common resistor and capacitor values and types, along with quantities of commonly-used semiconductor devices. What pleasantly surprised me was that (as long as Dan comes through with this order, and it’s good stuff) if you look for deals and buy from the right places, it needn’t break the bank.

I can’t wait to have my own personal arsenal of resistors, fixed capacitors and trim caps, diodes, transistors, pots, toggle switches, DBM’s (Dan has ADE-1 DBM’s for $4.50 each), ICs and who knows what else. The teenage me would have been so excited to know that I would one day achieve heaven on earth 🙂

Once everything arrives, here’s the plan of action:

 

* Build an active bandpass filter for NT7S’ VRX-1 DC receiver. I’m excited to see what what Jason’s receiver sounds like with audio filtering

* Build a regen receiver for 80M so that I can listen to the weekly West Coast AM net – and maybe mod it for 40M

* Consider building a QRP AM TX for 40, which can later act as an exciter for a linear amp (you think I’m crazy enough to try AM QRP on 80 and 40?)

* Build K8IQY’s 2N2-20 Manhattan-style

* Remove the Tut80’s polyvaricon and modifiy it for tuning with a varicap, so I can use a 10-turn pot, then put the Tut80 in a more stout case made of PCB material

*Lots more things.

 

The above are just ideas and we’ll see which ones come to fruition and which ones remain in my head, but I think I have plenty to keep me occupied, especially considering the fact that I work at a snail’s pace (solder one resistor, take a swig of coffee and look out the window, solder another resistor, take another swig of coffee and play with the kitty etc etc.)

It’s going to be so much fun!

June 14, 2011

Low Solar Activity – The Beginning Of A New Era?

Today an announcement was made at the annual meeting of the Solar Physics Division of the American Astronomical Society, which is being held this week at New Mexico State University in Las Cruces. I’m going to directly quote today’s article on Space.com:

“Some unusual solar readings, including fading sunspots and weakening magnetic activity near the poles, could be indications that our sun is preparing to be less active in the coming years.The results of three separate studies seem to show that even as the current sunspot cycle swells towards the solar maximum, the sun could be heading into a more-dormant period, with activity during the next 11-year sunspot cycle greatly reduced or even eliminated.”

They’re saying that the next solar cycle, cycle 25, may not even happen at all.

Say what? Did I hear that correctly? Can you say that again please?

They’re saying that the next solar cycle, cycle 25, may not even happen at all.

Wow.

As a 14 year-old teenager growing up in a village in England, I remember sitting in front of G4DSE’s beautiful Drake station. He had a cubical quad on a tower in the field behind his house. This would have been in late 1977 or early 1978, during cycle 21.  I don’t remember what band he was on, but I do distinctly recall him putting me on the microphone and letting me chat to a teenager in California.  The west coast. Wow. Amateur radio was truly wonderful! More recently during cycle 23, the FT-817, Buddipole and myself were able to work all over the globe with just 5 watts. Now with this news that we may be heading into a lengthy period of much-diminished solar activity, it means that I may never get to see a really good sunspot peak again.

Now I realize that all is not lost.  I know that things still happen on HF (particularly the lower bands) during periods of low sunspot activity. I know that all the weird and wonderful modes of propagation on the VHF bands are still in effect (a lot of folk have been having a ball on 6M recently) and there are incredible opportunities to do great things such as moonbounce (even more accessible now thanks to Joe Taylor’s JT-65 software).

The thing is that my view of ham radio is heavily HF-oriented. The HF bands are, for me, the mainstay of amateur radio. Those early memories watching local amateurs work the world with ease (and later doing so myself) are a core part of my amateur radio experience.

Now how can I get myself a 3 element beam and 1500W on 80M…..?

June 3, 2011

The End Of A Good Relationship – FT-817 Up For Sale

Filed under: Amateur Radio,Ham Radio,QRP — AA7EE @ 11:24 pm
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I haven’t owned that many rigs in my amateur career which is surprising, as I’ve been licensed since 1978.  There was the 2M FM VFO-controlled transceiver designed and built by a local amateur, who was also a regular contributor of technical articles to the RSGB’s RadCom. He gifted it to me, and it became the first rig I owned. I won’t mention his name though because whenever I transmitted with that rig, I also unknowingly emitted spurii on the input of the local police repeater. Luckily the gentleman from the police department who drove up to our house, putting the fear of God into my 15 year-old heart, was also a licensed amateur. I was given a stiff warning and solemnly promised not to transmit with that radio again. Shame really, as I received reports of beautiful audio (probably because the signal was as wide as a barn door.)

Then came the Icom IC-22A, which my Dad bought for me from a local amateur (thanks Dad!) I later swapped that with Steve G4GXL for his Trio 2200G, used it for a bit and then sold it to buy a Palm II 2M HT. 2M FM was a very active and friendly place in the late 70’s/early 80’s and although my time would probably have been better spent on the HF bands (or testing the limited of VHF propagation on SSB and CW), my teenage self just wanted to pick up a mic and blab away as much as possible. Somewhere along the line an old AM Pye base station full  of vacuum tubes was converted to FM and pushed into service to access the local repeater.  I did spend a glorious few weeks with the Redditch Radio Club’s HW101 in my bedroom.  Not sure how I convinced them to let me borrow it, but lots of fun was had working all over Europe.  Around that time I built a QRP 80M DSB rig, and with the 80m dipole situated just 15 feet above ground, didn’t work very many people with the very few watts of DSB it put out, but was fascinated by the simple concept of it’s direct conversion receiver, which worked very well.

I’ve probably left a few out here and there, but those were the rigs of my early amateur career, after which I left home to attend University, then moved to the US, and except for a few short-lived returns to the world of amateur radio, was largely inactive for around 20 years. (Edit – I just remembered an FT-415 HT in the late 80’s and a TS-520 in the mid 1990’s – funny how these rigs came into and left my life!)

Then came the FT-817. I bought it in 2002 whilst in another phase of getting back into amateur radio and it just so happened that the sunspots were pretty good then. Long story short – I worked all over, on many bands with the 817. I took it to work and operated 10M on my lunch break, worked into Oscar 14 with a set-top whip (and later an Arrow Antenna), and had all kinds of fun on SSB with a Buddipole set up inside my second floor apartment in Hollywood. I’d also take it on regular trips to Canada and check into the 10-10 net from Calgary in Alberta. More recently, when I decided I wanted to try WSPR, the 817 rose to the task, and alongside a couple of kit-built rigs, it helped me when I decided to get serious about the code a couple of years ago. It has been a fun do-it-all rig for me.

But now I want to sell it. The initial trigger was the announcement of the upcoming Elecraft KX3. Indeed, I may well purchase one after it has been out for a few months but for the time being, I like the idea of not having a commercially built rig in the shack at all.  Jason NT7S is making headway with his new kit transceivers and I hope to build one for 40M and another for 20M. Along with the Tut 80 and the Norcal 2N2/40, I’ll then have coverage of 80, 40 and 20. Who knows – if I work enough DX with those rigs, I may not even want a KX3 when it comes out 🙂

The initial plan was to put the 817 on eBay, but those sellers fees are looking a bit excessive, so it went up on Craigslist last night (hey, you never know), and then I’ll try it on QRZ.  Not sure if there are any other forums that are good for selling amateur radio gear, but eBay will probably be the last-resort course of action. The price I’m asking may seem a little up there, but it has both 300Hz and 2300Hz Collins mechanical filters as well the BHI DSP module.

It’s going to be fun living just with gear I soldered together myself!

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