Lesser Chirpy - a VERY simple 10m transceiver

This design is a couple of years old and evolved from Chirpy. Unlike the original design, chirp on 10m is negligible. This design really works and gives credible results on 10m with just a handful of parts. Sensitivity could be better  with a few more parts, but not this simple!

See https://sites.google.com/site/g3xbmqrp3/hf/chirpy .

QRP rigs

See http://www.vanyi.net/homemade/homebrew-hf-ssb-transceivers/ .

This page has a nice collection of links to a range of (mainly) homebrew QRP transceivers for various bands. Well worth a visit and good browse.

Bug keys

Kent twin paddle key

Although not a frequent or very good CW operator, I do like to try QRP CW from time to time, usually with a straight key I've had for over 40 years. With rubber stamp QSOs on HF I can usually manage OK. The problem comes when people ragchew and I lose concentration!

Some years ago I bought a beautifully made Kent paddle key but I've hardly ever used it because I kept making mistakes. So, today I dug it out and decided to persevere with it on 40m CW. I managed a nice (unexpected) 2-way QRP QSO with Rick DK4QK who, despite my sending, managed to copy everything. Later I worked DM0E on 2-way QRP as well, using the bug. Like all things, good CW comes with practice and use. Using a paddle key should allow me to send better and faster CW with a little bit more practice on my part.

So, if you hear me calling CQ on 40, 20 or 10m in the coming days on CW, and there are plenty of mistakes and extra dots, then you'll know who it is.

A PSK31 QSO

Well, the little grandchildren have gone back home to mum and dad so the house is very quiet (and tidy!) again. This afternoon I decided to do a bit of QRP on 20m as a change. First a nice 2-way QRP QSO with Emi IZ4RDX who was running 5W (me 2.5W) and then a PSK31 QSO with Luis EA3UV. Neither contacts were great DX, but fun.  For the PSK31 QSO I decided NOT to use those pre-prepared messages and instead just keyed in what I wanted to say as the QSO went along. It felt like a real QSO, which was nice.

Tomorrow I hope to get back to the optical beacon work, but after 4 days of (lovely) little grandchildren this afternoon I just needed to "chill" as they say.  The plan is to build a beacon TX that will allow a range of subcarriers and also continuous subcarrier transmission as well as CW and QRSS beacon messages. I hope to get out "over the horizon" looking for the signal later in the week. Watch this space - literally if you are nearby, HI.

ARRL DX CW contest

Until I read about it on G4ILO's blog, I'd quite forgotten about this big contest. Rather late on Sunday afternoon and evening I decided to have a go and see what could be worked on 40 and 20m. Although I managed a few US contacts with the 2.5W QRP I do find CW contests hard work: people send SO fast and by the time I've called with my straight key they've usually already had another QSO.  I suspect many these days use keyboards and auto keyers most of the time in contests. Actually I quite enjoy the odd SSB contest as I can talk (nearly) as fast as anyone else. Even with 2.5W SSB it is surprisingly easy to make contacts in a big contest, especially late in contests when the big guns are looking for new stations to work.  Overall, I prefer experimentation, but a contest just for fun can be quite cathartic.

Back on 137kHz TX

QRSS and CW beacon TX for 137.685 kHz

Today I went into the shack with the intention of making a new transverter for 137kHz based on my recent design for 472kHz.

Instead, I ended up building a new CW, QRSS3 and QRSS30 8W beacon transmitter using an IRF640 PA device. This evening and overnight the beacon will run QRSS3 on approximately 137.685kHz and I have requested reports and screenshots.

The antenna being used is my 20m spaced earth-electrode pair set-up used very successfully on 472kHz last weekend. On 137kHz signals are much weaker than on 472kHz, so I await reports with interest.

The whole unit runs quite cool when housed in a plastic box. Switches on the front of the boxed unit allow up to 7 pre-programmed messages to be beaconed at varying speeds. As normal, I use the K1EL beacon chip for the beacon message generation. The signal source is a 3.579MHz crystal in a divide by 26 circuit implemented in a PIC like device and kindly supplied to me by a French amateur Francis F6HSI a few years ago.

First CW QSO on 472kHz

Although my local noise level is a little lower on 472kHz than on 500kHz it is still not low, so working stations with the current TX antenna (using it on RX and TX) is not the best of set-ups. Nonetheless, this evening I had my first 2-way QSO (on any band) of 2013 and this was on 472.5kHz CW with G3XIZ in Biggleswade. We exchanged 579 reports, although I was rather generous with my report really because of the local SMPSU noise. Also heard was G3YXM who was rather weaker than Chris.

I am now continuing with WSPR beaconing and will run the beacon (TX and RX) through the night for the first time on the new MF band. So far my best DX report is from Germany, but I would dearly love to be copied, if just once, by TF3HZ in Iceland. Haldor is monitoring and it is just about at (or just beyond) the limit of range with my 10-20mW ERP.  With QRP I have learned that nothing seems to be impossible with a bit of perseverance and good luck.

CW QSO with M0FMT on 500kHz this evening

After the usual reports from all over the place on my 50mW ERP 500kHz WSPR I took a listen around for some CW stations this evening. G3XIZ was calling CQ and listening on 80m crossband, but then I heard Pete M0FMT not too far away in Hitchin calling CQ. He heard my reply and gave me 529 report. He was about 549 with me deep in the noise that remains on the band. A few days ago this QSO would have been impossible because of the local noise here. The offending noise source (central heating controller SMPSU) is switched off!

Barbados on 10m QRP

8P6BX in Barbados

Whilst looking for QSOs with Lesser Chirpy on 28.060MHz this afternoon I heard Ron 8P6BX in Barbados calling CQ. No go with 70mW so I turned on the FT817 and worked him with 5W getting a 569 report. He was running 3W and was peaking 589 with me. It was a nice, solid 2-way QRP QSO on CW.

Weak signalling comparisons

Over the last few days I've been trying out my Lesser Chirpy 10m 80mW CW rig putting out CQ calls on 28.060 periodically and listening for replies and RBN reports. In three days I've only managed 2 RBN reports at around 3000km with it. So, this morning I fired up the hombrew WISPY WSPR beacon on 10m to see what happened. This runs about 6dB more power at around 200-250mW pep effective on the WSPR band. On the first transmission I got 3 reports immediately at 2200-3500km. With WSPR it is SO much easier.

Conclusions? Well if you just want to know what propagation is like then a small homebrew WSPR beacon is all you need. If you want the fun of the chase and the chance of a few QRP CW contacts with a human then the Lesser Chirpy rig is up for the challenge.

Life is too short to sit there endlessly calling CQ with the key though. So, I think Lesser Chirpy will be brought out when  conditions and activity are good. Otherwise WISPY will whisper away quietly in the shack whilst I get on with designing interesting new little projects, HI.

UPDATE: After a few hours of 10m WSPR at 200mW I had a page of reports out to around 6500km. Back on 10m CW I tried a brief call with the FT817 at 5W and got a couple of USA spots on the RBN. A further 30 minutes of calling CQ with the 80mW transceiver and no reports or QSOs. Think I'll have to come back to 10m QRPp another day!

Lesser Chirpy reaches Cyprus

No QSOs this morning yet but a RBN report from 5B4AGN in Cyprus with the 80mW lesser Chirpy 10m CW transceiver to the Homebase-10 halo. This is the first time I've looked for RBN reports with this tiny transceiver.

Reverse Beacon Network report for 80mW Lesser Chirpy

When I got back from my grandson's birthday party in London in the late afternoon I put out about 10 CQs on 28.060MHz with the rig, but no QSOs or RBN reports. I shall try again during the week.

CW from Mars

The latest NASA rover "Curiosity" apparently imprints JPL in CW on the Martian surface as a result of its tyre pattern. See http://www.tyrepress.com/News/OFFBEAT/25967.html . If I recall correctly my callsign is on a microchip on "Curiosity" (see post last autumn).

On-line CW training at LCWO

Typical LWCO log-on page

If you are like me then your CW skills are not the world's best. Even though I am a G3 and licensed since 1967 my CW really is pretty pathetic. On an HF QSO when exchanging callsigns, reports, and serial numbers I'm usually OK, but when ragchewing with seriously good CW operators I'm embarrassed by the amount I miss. Some operators are very good and slow down, but not everyone.

However, for we CW duffers, help is at hand: http://lcwo.net/ is a rather superb on-line CW training facility that I believe could really help improve CW skills with a few minutes' effort each night. I have been to the site before and managed to improve my speed a bit but need to return there and try some more. All sorts of CW training is available at all sorts of speeds. If you want to use CW, which is an excellent mode especially for QRP, then this is worth a visit.

2m/70cm DXing

See http://www.f9ft.com/ antennas

On a few occasions in the last year I've operated /P in the RSGB's UK Activity Contests (UKAC) on Tuesday evenings and thoroughly enjoyed them. Even with just a small halo on 2m and a 4 el yagi on 70cms I was surprised how much could be worked and the high levels of activity.

It is some years since I've used 2m and 70cms from home with a horizontal yagi and I am tempted to erect something to give it a go. I know that outside of contests activity these days is low, but it still seems like worth doing. Whether I erect a rotatable yagi or a stacked turnstyle remains to be seen. It is a long time since 2m was filled with G8 stations using FT290s, 30W linears and Tonna 9el yagis!

Right now I have other antennas erected on the 2 small masts attached to the house and it may be some months before I make changes, but maybe I will get something in the air and see what happens. As well as SSB/CW DX there is so much more to explore these days with digital modes.

Gmail Tap

OK it is April 1st but this is actually not such a daft idea http://mail.google.com/mail/help/promos/tap/index.html

10m good despite the flare

Today all the propagation forecasts were showing poor conditions on HF. Despite this, 10m was well open this afternoon to the Middle East, Africa and South America with good signals received. My only QSO so far has been with JY5HX when running 5W CW here.

The lower part of 10m had several Russian (?) CB stations including one operating almost on 28.060MHz, the CW QRP frequency. Use it or lose it folks.

A Czech Chirpy from OK1CDJ

Ondra OK1CDJ kindly sent me some photos of his version of my 10m chirpy transceiver. Currently he is getting around 50mW out, a little lower than on samples made here. I have suggested some things to check and possibly change. I really must find a way of making it chirp less, HI.

See http://translate.google.com/translate?client=tmpg&hl=en&u=http%3A%2F%2Fblog.ok1cdj.com%2F&langpair=cs|en for an English translation of Ondra's blog.

You Kits SSB transceivers

For some reason I have missed the news that YouKits are producing (or about to) 2 band and 4 band HF SSB/CW transceiver kits at very reasonable prices. See http://www.youkits.com/ . One is a backpack and one a handheld. Quite interesting. See TJ2A and TJ4A code numbers on their website.

10m Chirpy Measurements

Last week G6ALB made a copy of my Chirpy 14 component transceiver for 28MHz CW. Andrew had access to some better calibrated test equipment and carried out some RF power and sensitivity measurements both on his version and on my second original unit - the first was just a rat's nest on the bench.

Both on my version and G6ALB's version the measured RF power out was in excess of 200mW, which is around 2-3dB more than I had crudely measured. The RX sensitivity on both was such that below -100dBm (around 2uV) was audible in our earpieces in a quiet room. Backwave carrier on TX was rather too high at around -10dBm. Second harmonic was also only around -6dB, so a low pass filter is really a necessity apart from casual short tests.

It does seem that the simple design is reproducible and its performance not at all bad for something this simple. The only major shortcoming is the chirp.

CW training on the internet

If, like me, your morse code could be improved then you may like to go to http://lcwo.net/main and see the array of training material available there. It is probably the best place on the internet where you can brush up your skills.