How simple can you make a transceiver?

 When I was fit (before my stroke!) I liked the challenge of "something for nothing".  This is how this little 80m CW transceiver came about. It is hard to get much simpler.  

My main issue was netting the TX to the RX frequency. I am sure this is a solvable issue. This has been on before, I know.

I think it was in GQRP SPRAT many years ago, but I honestly cannot remember.

See https://sites.google.com/view/g3xbm4/home/hf-mf-and-lf/homebrew/80m-feter-transceiver

Back on QRP 80m FT8 (Friday)

At the moment I am back on 80m QRP FT8 with my QMX+ and the coax up to my 2m big-wheel as the antenna, tuned via an ATU.

Lots of spots already from across Europe. See map to see where I am being spotted.

I am surprised how effective this "Heath Robinson" antenna is on 80m.

UPDATE 2218z:  176 stations have spotted me on QRP 80m FT8. 404 stations spotted here on 80m FT8 RX.

80m QRP FT8 (Friday)

So far today, with my "ad hoc" 80m antenna (coax outer tuned via an ATU and the QMX+) 27 stations have spotted me. See map.

80m the easy way

In the last day my QRP 80m FT8  has been spotted by 58 stations across Europe using just the outer of the coax up to my 2m big-wheel tuned with my ATU. 355 stations have been spotted on RX from across the world on 80m FT8 RX.

80m QRP FT8 (Thursday)

Currently I am on 80m QRP FT8 using my QMX+ into an ATU and the outer of the co-ax up to my 2m big-wheel antenna. Lots of spots on RX and on TX spots by 19 stations around Europe.

How few parts?

One of the aspects that I enjoyed was seeing how few parts were needed to make QSOs. This is one of the simplest circuits.

See https://sites.google.com/view/g3xbm4/home/hf-mf-and-lf/homebrew/80m-xbm80-2 .

80m FETer transceiver

Years ago I was inspired by a circuit for a 40m transceiver by W2UW who is now a SK. My challenge was to see if I could make an 80m version with even fewer parts. 

This is a complete transceiver using just a single FET and very few components. It is detailed on my website.

FETer transceiver (2008)

This was another of my attempts to get something for nothing! 

It worked remarkably well, but I struggled with netting the RX onto the TX frequency so I was afraid of clobbering someone else. It was an adaption of a circuit for 40m by W2UW but made even simpler. It appeared in SPRAT some years ago. 

Some have duplicated it and achieved some remarkable DX.

See https://sites.google.com/view/g3xbm4/home/hf-mf-and-lf/homebrew/80m-feter-transceiver .

Crickey - 2008! I must be old  HI 😀

Someone else trying my designs

 It is always good to see others trying their hand at my designs. DX Explorer has a video of him breadboarding my 2 transistor 80m transceiver. My designs are always a starting point. Pretty sure you will be able to improve them!

See https://sites.google.com/view/g3xbm4/home/hf-mf-and-lf/homebrew/80m-xbm80-2 .

What next?

 As I mentioned in an earlier post today, 630m WSPR seems to have "gone off the boil" and I may try something new over the spring and summer. 

I want to try 8m QRPP WSPR using 10mW and ISM rules (open to anyone in the UK without a licence, possibly in your area of the world too?).  This is mainly a daylight challenge.

Is there a new nighttime challenge? A band that remains good at night. Possibly 160m or 80m using the earth-electrode "antenna" in the ground? I could try FT8 on these bands perhaps.

80m QRP FT8 (Tuesday)

My 80m QRP (2.5W) has been on for the last few hours. My "antenna" is the (almost invisible) earth-electrodes in the ground on which the match is very good. I do not know the ERP on 80m.  2 QSOs have been made with one being PE4BAS, Bas, (450km). Results on TX and RX are far exceeding what I expected. My furthermost spot on TX is UN7MAU (3446km) - quite amazing.

UPDATE 2015z:   QSYed to 630m QRP WSPR.

How simple can you go?

This has been on before, but I make no excuses for posting it again. One of the challenges in amateur radio is to see how simple a complete transceiver can be made that really works. This is just one possibility. There must be many others. My main issue was adjusting the RX to be precisely on the TX frequency. Maybe you have some ideas?

XBM80-2 80m ultra-simple rig

This has been on before, I know.

Some years ago, I wanted to see how simple one could make a rig that actually worked. There is no doubt at all that the rig can be made better with more experimentation with values and other things, but I was quite surprised that something this simple worked.

Please do not (ever) be afraid to use my designs as starting points. If you can make something better, great. If it totally fails, just start again! 

See https://sites.google.com/view/g3xbm4/home/hf-mf-and-lf/homebrew/80m-xbm80-2 .

80m QRP FT8 using the earth-electrode "antenna" in the ground

80m FT8 spots of my QRP using the
earth-electrode "antenna" in the ground

As I managed to match the FT-710 to the earth-electrode "antenna" in the ground, I was on 80m QRP FT8 early last evening and again now. So far, 60 stations have spotted me. It certainly works! 

Later, I may try calling into the CDARC (Cambridge) 80m net.

UPDATE 1000z: I tried to go on the CDARC 80m net, but heard nobody. Noise level was S9, so I QSYed to 10m FT8 instead on the FT-710 at QRP level. Plenty of spots on TX and RX.

80m FT8 tonight?

Just might try 80m FT8 TX this evening after dark when 10m is no good. It means matching the FT-710 to the earth-electrode "antenna" in the ground and setting WSJT-X for use with the FT-710. For the last few days I have been using the QDX.

UPDATE 1606z:  As 10m does not exactly look great, I might swap to 80m FT8 quite soon.

80m FT8 (Tuesday)

As 6m was so poor, I QSYed to 80m FT8 using the earth-electrode "antenna" in the ground. Although I am receiving spots of my signal from right across Europe, it says I am receiving none. This is rubbish as I can see loads of stations locally. Either there is a delay with uploads from me or, more probably, my spots are not getting to PSKreporter. Shortly I shall do reset to see if this cures it.

UPDATE 1922z:  The reset did the trick with lots of spots on RX. On TX 36 unique station spots of me so far.

UPDATE 2119z:  112 stations have spotted my 10W 80m FT8 TX this evening. Now QRT on all bands.

80m FT8 (Monday)

 At 1255z, I moved from 160m FT8 (no spots) to 80m FT8 using the earth-electrode "antenna" in the ground. The FT8 frequency on 80m seems to be 3.573 MHz.

80m FETer transceiver

One of the challenges in amateur radio is how simple can you make a rig that really communicates? Some years ago I designed and built this unit for 80m CW that appeared in GQRP SPRAT. It is one of the simplest transceivers you can make. It really works!

See https://sites.google.com/view/g3xbm4/home/hf-mf-and-lf/homebrew/80m-feter-transceiver .

How simple can a rig be?

This was a challenge I wanted to have a go at. This is probably one of the simplest transceivers one can make. My inspiration came from a 40m rig by W2UW who is now sadly a silent key. My wish was to make it even simpler. My main issue was netting. The RX worked well. This appeared in GQRP SPRAT, although I cannot remember when.

There is a video on the website.

See https://sites.google.com/view/g3xbm4/home/hf-mf-and-lf/homebrew/80m-feter-transceiver .

How simple can you make a transceiver?

Many years ago, I built the XBM80-2 80m CW transceiver. It never got cased, but shows how simple a transceiver can be! Somewhere recently I was told that it is a good idea to keep DC from hitting the crystal earpiece. If this is the case, it is probably worth adding a DC blocking capacitor between the audio transistor and earpiece. I have no idea if this is an old wive's tale or fact.

See https://sites.google.com/view/g3xbm4/home/hf-mf-and-lf/homebrew/80m-xbm80-2 .