Dave Richards AA7EE

February 15, 2011

A Listener Report and The Magic Of Radio

Filed under: Amateur Radio,Ham Radio,QRP — AA7EE @ 9:45 pm
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I don’t know what happened.  I lay on the bed a couple of hours before bedtime last night for a quick nap and the next thing I knew it was 2:30 am and my nap had turned into half a night’s sleep. This was not a bad thing as it meant I was now awake and could turn the radio on to see what was cooking on 40.  The only antenna I currently have is a co-ax fed 40M inverted vee at 47 feet above ground. In theory, the only 2 bands I can operate with this antenna are 40 and 15, but I received a 599 from W5TTW on 10M yesterday using this antenna (tuned at the transmitter end).  He was 1600 miles from me in Texas. It never hurts to try!

Back to this morning and 5W of CW on 40. I worked K4TE 2000 miles from me in Alabama, and K9KHJ 1800 miles distant in Wisconsin. Although our QSO was brief due to the high band noise at my end, it was a pleasure to work him. His callsign is a tribute to the station KHJ in Los Angeles, which was legendary in the boss jock era. It was that callsign that first caught my attention when Danny left a comment on a previous blog post about powerhouse amateur stations. As a former DJ/voiceover/production person, the letters KHJ just popped out. Great that we got to QSO and it happened without the aid of Twitter, e-mail or Facebook; it happened the old-fashioned way – we were both on 40M at the same time. After that, an exchange with W2ZRA in Long Island confirmed that 40 was in good shape (with the exception of high band noise) and I was a happy camper. I did call CQ one more time but didn’t try too hard; I was becoming sleepy.

About an hour later, just as I was thinking a few more zzzz’s might be a good idea, an e-mail from Steve KC2VBU landed in my inbox. He had heard my final CQ on the direct conversion receiver of his Rock-Mite at his QTH in New Jersey. Given that I was only a 229, on the wrong side of his rockbound frequency of 7028 and his Rock-Mite puts out just 600mW, he didn’t call me, figuring a QSO was unlikely to ensue.  Steve wrote:

GM.  As is my habit most every  morning as I putz around before heading out to work I fired up my SWL Rockmite (have two) and listened in a bit on 40M.

About 12:37z (7:37ET) I thought I heard a “7” call and after listening to a few CQ’s I had your call down AA7EE. This is unusual for early mornings on the Rockmite so I looked you up in QRZ (nice pic ha!) and saw you were most likely operating QRP so I had to let you know ur sig this morning went ~2550 miles (if you were operating in the the Oakland area) at least to the NYC metro area. Maybe this is not unusual for you but it is on this end and I do a lot of listening on 40 & 80M.

I just replied to Steve, thanking him for taking the trouble to send an e-mail report. Part of my reply read as follows:

Even in this age of being able to use the internet and the Reverse Beacon Network to see where I am being heard, the extra personal touch of an e-mail report is very welcome.  To think that as I was sitting in my room on the west coast in the early hours of the morning, someone was straining to hear my signals on the east coast, and successfully decoding them (especially with a Rockmite!) is a thrill.  It’s the magic of radio.

That pretty much sums up a lot of the magic of radio for me. It’s a combination of the technical aspect and the personal aspect that gives radio a mystery and a romance.  Thanks for the report Steve!

February 8, 2011

The USBtinyISP – The First Step In Building Etherkit’s New CC-40 40M QRP Transceiver

Jason NT7S is currently busy building the first beta of his new CC-40 40M QRP transceiver that uses the PCB’s he designed. It hasn’t been completely smooth but then, that’s why beta versions are built before kits go out to the general kit-buying public. The beta builders are beginning to congregate on our private beta builders forum on the etherkit site (I’m sure we all feel very special – I know I do) and we’re all ready and raring to go with our beta builds. Among the beta builders are Brian N1FIY and Mike WB8ICN who are more experienced at building NT7S designs than myself, as they have both built the Willamette Transceiver.  Brian’s Willamette is a little more than half complete. Mike’s is finished and is a real beauty! I did build Jason’s VRX-1 Direct Conversion Receiver as offered by 4SQRP, but it was a simple and straightforward project, so I haven’t truly lost my NT7S virginity yet. Good grief, that didn’t sound right.

In case you’re tuning in for the first time. Here’s a link to the page on Jason’s blog in which he describes the features of this upcoming transceiver. Bear in mind that these are preliminary features; things may change a little by the time the CC-40 reaches the production stage, and also bear in mind the fact that the picture in Jason’s post is a prototype; the kit you receive will have a beautifully produced PCB (oh – and the final version employs surface mounted devices for most of the active and passive devices – in other words, nearly all the components are SMT’s.)

I have to take issue with the name of your blog post though Jason – it’s not exactly lifted out of the pages of the first lesson in the class “Effective Marketing 101”!  Contrary to the title of the post, I think a lot of folk are going to care about this transceiver. The microcontroller, which will control muting, frequency readout, keying, battery status, and possibly other functions in the future can be programmed in-circuit.  By the time the kit is available on the etherkit site, I’m sure that the firmware included on the controller will be very capable, but if you ever need to update the firmware, you’ll be able to do so with the aid of a simple device like the USBtinyISP.

For beta builders like myself, it’s pretty important that we are able to update the firmware ourselves, as Jason is still putting the finishing touches to it, and we won’t have anything like a final version of the firmware with our beta kits.  We could mail the transceiver back to him for re-programming, but it’s probably simpler to do it ourselves, which is where the USBtinyISP kit from Adafruit Industries comes in.  It’s an In-System-Programmer (hence the acronym) for AVR microcontrollers, meaing that to flash new firmware onto the chip, you don’t have to take it out of circuit – you can do it while the chip is still installed on the board in-circuit.

This is hardly worth that much of a description as it’s such a simple kit to build, but I like taking pictures of what goes on here and posting them, so here’s the bag the kit comes in:

You’ll notice that as well as being used as an AVR In-System Programmer (our intended use), it can also be used as a SpokePOV Adapter. What the heck is one of those, I wondered? I thought it was some highly technical buzz-word that had passed me by (as in “Hey Bill, you were coming in 599 when you were using the SpokePOV Adapter wired in parallel with the wim-bim-fertang-fertang-bus-stop-ole-biscuit-barrel.”) Turns out that Adafruit sell a kit for a thing called a SpokePOV which is an array of LED’s that you fix to the back wheel of your bicycle.  POV stands for Persistence Of Vision, and the idea is that as your back wheel spins round, the individual LED’s appear as solid blocks of light.  You can use this USBtinyISP kit to program the patterns that appear on your back wheel, if you also have a SpokePOV kit from Adafruit.

If on the other hand, you’re a boring old fart like me, and just want to use the USBtinyISP to flash new firmware onto the AVR microcontroller in your new CC-40 from etherkit (or any other AVR microcontroller for that matter) just make sure to install wire jumpers in place of R4 and R7 per the instructions.

Look what a simple kit this is:

Here’s the completed board:

and fitted inside the case:

Hey, if I can build this, I can build an Elecraft K2 right? (Well, joking aside, I’m sure that there is nothing hard about the K2 other than an awful lot more parts to be stuffed and soldered.)

Now to find me some small tweezers and some .02″ diameter solder for all those SMT devices in the CC-40 and I’ll be all set.

There’s only one other thing for me to do to in order to get ready for this cool new QRP transceiver, and that is to keep plugging away at the CW, but that’s a subject for another post.

February 1, 2011

KD7KAR’s 40M Regenerative Receiver

Filed under: Amateur Radio,Ham Radio,QRP — AA7EE @ 4:31 am
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For the second time since I’ve been active on CW (about 18 months) I had a QSO today with a station who revealed that he was receiving me on a regenerative receiver. This was a first in a way, because the last time was with W7QQQ whose regen receiver uses a tube.  KD7KAR’s receiver uses an MPF102, so this represented the first time I’ve been in QSO with a station that was using a solid state regen receiver to receive my CW sigs.

As a teenager in England, and eager reader of RadCom (the RSGB publication) and Practical Wireless, I remember seeing circuits of simple regenerative receivers employing FET’s and wondering how they performed on the ham bands. I did own a one tube shortwave regen receiver when I was about 16 or 17 called the HAC (short for “Heard All Continents”). I used it a few times to listen to amateurs but didn’t think of it as a serious receiver for amateur work. The tuning was a bit coarse, so that didn’t help.  I know that regens were very popular with hams before the onset of the superhet but find it interesting that they can still be used effectively today.

They certainly are effective.  Rob KD7KAR gave my 5 watt signal a 579. My 5 watts traveled 400 miles and were detected by his MPF102 regen receiver.  It was a design by Doug De Maw W1FB.  Pretty impressive.  He was also using a 10 watt (also homebrew) crystal controlled transmitter, which was crystalled up for 7030KHz. He did comment that being rockbound was a bit limiting, but if you’re going to be rockbound on 40M, 7030 is a good place to be.  I have full VFO control and still spend much of my time on 7030 anyway. One thing about regens – Rob said that he has to tune it with a broomstick handle! For anyone who has not used a regen receiver, they can be very sensitive to hand-capacitance effects.

Wish I had a picture of Rob’s set-up to post here.  Perhaps if Rob sees this post he’ll be able to help out.

Every QSO is different. Some are memorable because of the distance, or the rarity of the location contacted, others are memorable for the quality of the conversation or some other type of human interest.  This QSO fell into the latter category. Also, every QSO I’ve been having recently makes me think of how much more fun it will be when I’m beta testing the new CC-40 transceiver from etherkit and can report to the other station that I’m running a yet-to-be-released brand new QRP TX/RX for 40M.  It’s going to be fun having the CC-40 PCB sitting on the bench in QSO:

“Rig hr is CC40 BT Pwr 2W 2W to inverted vee at 47ft”.

Brilliant. Can’t wait.

Thanks for the QSO KD7KAR – and loved hearing about your home-brew station!

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