10m 134km GDX tests this evening

This evening G3WKW and I are trying to span 134km on 28MHz WSPR. I run 2W to a vertical and Bob runs a little more.  Despite Doppler and rig drift problems we managed the path (just) on 144MHz this week.  28MHz may be much weaker but with far less Doppler and rig drift. We shall see. With WSPR about 12-14dB better than CW we have the best chance.

UPDATE 2200z: Nothing at all seen since 1816 (USA) and 1824z (Es).  Will keep looking but not hopeful. No GDX seen at all.

10m still wide open

My first 10m WSPR transmission with 2W to a small antenna after lunch was copied in the  middle of the USA, in Canada, Israel and South Africa. Sunspot count today is 196. Conditions appear to be very good  still.

10m WSPR - excellent results

As my building skills are still poor because of my stroke, I have been sticking mainly to WSPR mode, today on 10m. Results on 10m have been excellent copying stations from S.Africa, USA, Finland, Israel and central Asia,with my own 2W getting reports from all over the place including  Israel, Canada  and the USA. A sunspot count of 245 no doubt helps! It will be fascinating to  see what 10m spots are possible when the sun is very quiet again. 4X1RF manages to spot me most days when I am on. For me, 10m DX propagation closed at around 1640z.

Unique WSPR reports on 10m (2W) up to 3pm

Back on 10m WSPR with WSPY TX

Unique 10m WSPR spots using WIPSY TX today

Having given up on 20m CW this morning, I fired up the 10m WISPY beacon TX running around 250mW to see what spots I got. During the day I caught a couple of Es openings. 4X1RF seems to spot me whatever I do/run and on most days!

I have still to put the TX and RX parts of this project together (both parts have been separately tested) as a full WSPR/PSK31 transceiver for 10m.

10m WSPR

My 10m WSPR system has been running most of the day with powers between 500mW and 2W. The only reports were from 4X1RF at 3519km. Best DX station copied here was DU1MGA at 10710km.

One of the reasons I like WSPR is that you can do other things at the same time whilst checking on how propagation is changing.  I am really looking forward to running WSPR in the quiet sunspot years on 10m and expect far more openings that might be found by calling CQ on CW or SSB with 5W.

Going loopy on 10m

Prototype 10m TX loop using 6mm copper pipe

Today I've made a small TX loop for 28MHz CW/WSPR using an odd piece of 6mm copper pipe I had around the place. As I don't want to move the frequency much and the maximum power out will be 5W (usually far less) I have used a small length of twin core mains cable, trimmed to resonance, as the capacitor to resonate the antenna. The loop is matched to 50 ohms with a small coupling loop made out of RG58 coax. Bandwidth is quite sharp suggesting the loop is working as expected.  At the time of writing (early evening)  I've only copied one signal EK6RSC at 3586km earlier in the day and am still awaiting some reports on TX. The loop is mounted on a PVC pipe taped to the back of a chair in the shack.

If successful, the idea will be to put this up in the loft at the new bungalow and use it with WISPY and a small dedicated netbook PC to run 10m WSPR.

V5/DK1CE Namibia

Whilst in the shack this morning I turned on the FT817 to hear an unidentified (for nearly 10 minutes) CW station working people and giving 599 reports in the main. I called a few times and eventually got a 599 report, still not sure who the station was. Then, finally, he gave his callsign V5/DK1CE in Namibia. All the more pleased now I know that "3 blobs" on the FT817 is just 2.5W out to the halo antenna. And another DXCC entity this year.

10m WSPR today

Today my 200mW from WISPY beacon was not enough on 10m to get any reports. So, I went up to 5W with the FT817 and managed a few reports this afternoon. Conditions were not good. Nonetheless reports came in from North and South America and from Germany.

10m WSPR reports today with 5W and halo

More WISPYs on 10m

The G4SFS version of WISPY

Yesterday I received a nice email from Peter G4SFS who told me that he and Dave G6WZA had made a couple of WISPY 10m WSPR beacon TX units using the schematic on my website. A few values changes were needed - not unexpected - but that they are now working well and receiving spots from distant monitors. This is a photo of one of them. WISPY is a simple QRP WSPR beacon for 28MHz using a low cost 14.060MHz crystal and inexpensive 2N3904 transistors throughout.

Conditions on 10m have not been too great of late, although I did exchange reports with PY2SDR at 9616km and 4X1RF. Interestingly, there have been a few early evening WSPR reports from DL which I assume are probably a result of wintertime Es propagation.  At this time of year there is a mini-peak in sporadic-E propagation, so it is worth keeping an eye on 50MHz and 70MHz too.

First on-air testing of the Tenbox TX

This evening, with little sign of F2 propagation, I ventured out to test the range of the 10m Tenbox TX as it is currently. For the TX antenna I used the coax up to my 10m halo as a vertical tuned with the Elecraft T1 ATU. At the RX end, in the car, I used the FT817 with a small base loaded mag-mount.

Tenbox AM TXing with MP3 callsign message on the PC

What I should have thought about was the noise on AM from street lights! When the signal is strong in the village this is no issue at all, but traveling to the next village 3km away there were several spots where the buzz from sodium street lights just killed the little signal. Both antennas are compromised, so another 3-6dB of signal level should be possible with a proper 1/2 wave antenna at each end or with a better car antenna.

Maybe this project, although great simple fun, isn't going to quite meet my needs, whereas a DSB transceiver would?  Receiving the DSB signal as SSB and the improvement over AM will be around 9dB with better noise immunity. However a simple direct conversion RX would not be suitable to use (easily) with a DSB TX, whereas the AM Tenbox would be fully 2-way compatible with another identical AM unit.

Conclusions so far
(a) 6-10dB more may be needed to meet the design objectives with AM.
(b) It is worth repeating the very same test now using a DSB TX with the same power to compare.

More 10m (28MHz) Projects

With the Tenbox coming along just fine - I should have a completed breadboard version on-air this week - I am beginning to think that I could spend nearly all my free time designing different ideas for this, my favourite, band!

Here is just a brief list of some of my 10m ideas (all do-able with some time):

• 10m QRP AM transceiver (Tenbox)
• 10m QRP DSB transceiver
• 10m pocket SSB/CW "holiday" receiver
• 10m mixer-VFO controlled CW transceiver
• 10m compact portable antennas for mobile and hand-portable
• 10m VXO controlled QRP TX
• 10m phasing SSB transceiver (10W)
• 10m beacon RX
• 10m test box (power meter, ATU, SWR bridge, FS/mod meter)
• Modules for 10m rigs (VXO, mixer-VFO, LPF, TX strip, DC RX, AM modulator, audio power amp etc)

Now, as I like to do so many different things in this exciting hobby - including on-air operating some times! - it is unlikely all these will get done anytime soon.

What occurs to me, if I had the time, is that a mini-series in a magazine like PW or RadCom entitled "Ten Projects for Ten Metres" would be a nice idea. 10m is one of the best bands for homebrewing as layout is not too critical, as long as sensible RF rules are followed, antennas are small, superb DX is possible in the better years and Es DX possible for 4-5 months every year, local ranges are useful for nattering across town. All in all, this band has SO much to offer.

10m local range?

With the 10m AM Tenbox design coming along nicely I'm reminded of the fun we had in the early 1980s with 10m FM using converted CB rigs here in the UK. Using a converted CB radio with 4W FM into a vertical half wave antenna I was usually able to make contact with similarly equipped stations up to around 25-30 miles away pretty regularly. Certainly within a 5 mile radius signals were fully quietened, even to mobiles.

So, I am wondering how I'll get on with 0.5W of 29MHz AM? My expectation is that with a similar antenna (1/2 wave vertical - I currently use a horizontal halo) I should be able to cover 3-5 miles without too much problem. I'm wondering what sort of ranges people achieve with AM CB radios (WITHOUT add-on PAs!) where this mode is legal?  Running a few dB more power is no problem if required of the Tenbox design.

When 10m is wide open it is possible to work thousands of miles on FM but I always found that the competition was too great and therefore the mode is not well suited to DXing. The aim of the 29MHz AM Tenbox is just for very local communications and definitely not for DX working. In my mind I see the Tenbox being a modern version of the old Heath HW19 (the Tener) rig - see the image and data on the Rigpix page

WISPY 10m WSPR beacon video

A few people have requested a video of WISPY, my QRP WSPR beacon for 28.1246MHz. This video shows the TX beacon only. I have a companion RX breadboard that works well and at some point these will be combined into a small 10m WSPR transceiver.

Tenbox 10m AM RX video

It is hard to contain my enthusiasm for simple transceivers and super-regen receivers! This video shows just how well the RX breadboard for the little Tenbox 10m AM transceiver works. 1uV (-107dBm) is a very good signal and it will still detect a well modulated AM signal at -120dBm. Selectivity is not good with this type of receiver, which is the main drawback. However for its intended application - a simple transceiver for local nattering across town - it should be fine. Some people use super-regens as the IF stage of AM receivers. If a filter is added ahead of the super-regen IF this overcomes the selectivity issue but makes the RX design more complicated.

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.

Lesser Chirpy spans the Atlantic (10m QRP)

My 28.060MHz ultra-simple QRP transceiver was copied in the USA this afternoon. K3MM (Maryland) reported me on the Reverse Beacon Network as 7dB S/N at 15wpm on 28.060MHz. K3MM is in FM19JH which is 5886km away.

Initially I was unable to hear any stateside stations to call for a QSO. Still, the rig has now been copied across that big ocean! Power out into the halo is around 70mW.

VE2TH was coming through OK with 5W and might have been workable but the band faded out.

Testing the Tenbox on 10m AM today

Today I wanted check how good the Tenbox 10m AM receiver (part of the intended transceiver) was in real use as opposed to measuring it on a signal generator.

So, I set up my FT817 on 10m AM TX on the lowest power setting, which is around 150mW carrier, and fed this into a makeshift vertical tuned with the T1 ATU. Using my PC, I made a short message "G3XBM testing on 10m AM" that I played in auto-repeat.

I then went for a drive locally with the little super-regen RX in the car being fed from a vertical mag-mount antenna on the car roof. The only antenna I had was an ATX15 base loaded whip for 15m, so I pushed a few sections in to make it resonate on 29MHz.

Results were encouraging. Out in the car my 150mW AM TX beacon message could be copied out to about 2 miles away, although this was limited by QRM from W2VW (!) and VE3OWV (!) who were coming through with 59 signals on the RX on 29MHz AM. When they dropped carriers copy was fine. It's fascinating to think my 150mW AM signal was having QRM from 5000km away!

A super-regen is not really suitable for use when 10m is wide open, like it was this afternoon. Nonetheless I was able to copy stateside stations on 10m AM on a short base loaded mag-mount pretty well. For its intended purpose as a local across town natter box, I think the Tenbox is going to be fun. With 6dB more power out (my aim for it) it should be certainly possible to work G6ALB 3km away in the next village.

The next stage is now to build the TX part and test this.

More DX on Lesser Chirpy

Another report via the Reverse Beacon Network from 5B4AGN in Cyprus this morning, but no QSOs and no further RBN spots. A brief outing this afternoon in which I'd hoped to get across the Atlantic proved to be a disappointment. There is always tomorrow....

Rotatable dipole or HF halo?

DES Rotating Dipole

A new antenna is being advertised by InnovAntennas: a compact rotatable 15, 10 and 6m dipole with droopy ends so that the overall length is no greater than a single 10m dipole. It is called the DES-Rotating Dipole. The image on the right (from the InnovAntenna website)  shows the neat arrangement which can be fed directly from 50ohms. Without lossy traps the power rating is at least 5kW, rather more than I would ever need.

Now, neat though this is, I question whether it is really worth the expense. At this stage I have no idea of price but I would expect somewhere between £50-100? My simple Homebase-10 wire halo is MUCH smaller because the 10m dipole is arranged in a square. A 6m halo can be nested inside very easily and fed with the same coax. To add a 15m halo would only increase the size by 50%. Unlike the Cobweb antenna, my simple design could be assembled as a 3 band version for less than £15 with all new parts.

Homebase-10 10m halo

How much down is the halo compared with the nested dipole?  In most directions, apart from a tiny segment in the direction where the ends of the halo meet, less than 2dB. What is that in S-points? Hardly noticeable at all at about 1/3 of 1 S-point.

A dipole, if rotated, does have the advantage of being able to null out interference but I am not sure this is such a benefit. For me, it is either something like a horizontal halo which tends to be a "quiet" antenna picking up little local (vertically polarised) man-made interference or a small beam which would have some gain and directivity. However, the latter will only add about 0.5-1 S-point in signal level and, time you buy a decent rotator and the beam, you will have paid 10-15 times more for the privilege. A beam does add directivity and interference rejection, but is much larger. For me it is a "no brainer".  My simple little halo has allowed me to get QRP reports on SSB, CW and WSPR from all over the world. It is simple and works well.

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.