10m FT8 RX with the tiny loop and simple 10FT8R RX

It is now 0825z. I have been on 10m FT8 RX since before breakfast. So far, 21 stations spotted. Mostly Es from across Europe. 

UPDATE 1735z:  183 stations spotted on 10m FT8 RX so far today.  See map.

10m FT8 RX with the 10FT8R RX and the tiny indoor loop antenna

 For the last few hours I have been on 10m FT8 with the tiny indoor loop antenna and the 10FT8R RX. It is now 1143z and so far today just 4 stations have been spotted on RX. 

UPDATE 1251z:  7 stations spotted on 10m FT8 RX so far.

UPDATE 2105z:   37 stations only spotted today with the tiny loop. QRT shortly.

10m FT8 (Tuesday) - late start!

At 1457z, I turned on the 10FT8R 4 transistor RX with the tiny indoor loop antenna. After under 10 minutes, 20 stations already spotted!

UPDATE 1711z:  191 stations spotted so far today on 10m FT8 RX with the 10FT8R RX and the indoor tiny loop (see map).

UPDATE 1840z:  235 spots so far today on 10m FT8 RX.

UPDATE 2110z: 240 stations spotted on RX today.  QRT soon.

Yesterday on 10m FT8

I was again on 10m FT8 yesterday with the tiny indoor loop and my 10FT8R RX.  In all, 314 stations spotted.

10FT8R - improved schematic

A few people have wanted a clearer schematic. I have now uploaded it to my website. It was produced by Jay W5OLF. 

See https://sites.google.com/view/g3xbm4/home/hf-mf-and-lf/homebrew/10ft8r-rx .

10m FT8 RX with the 10FT8R

Just before breakfast I turned on the 10FT8R RX (4 transistors) with the tiny indoor loop antenna. It is now 0818z and 29 stations already spotted via Es.

UPDATE 0835z:  34 stations spotted so far.

UPDATE 0915z: 50 stations so far spotted today.

UPDATE 1131z: 101 stations spotted so far on 10m FT8 RX with the little 10FT8R receiver and the tiny indoor loop.

UPDATE 1426z: 164 stations spotted on 10m FT8 RX so far today.

UPDATE 1740z: 222 stations so far spotted on 10m FT8 RX with the furthermost W1JR (5267km) in New Hampshire, USA, I think this was Es (see map). No South Americans logged today on the tiny indoor loop.

10FT8R - continued experiments

This morning, I am again on 10m FT8 RX with the tiny indoor loop. Late yesterday, I removed the last AF stage, but spotted no stations. There were lots of spikes and I am not sure what they were. Later, I shall stick the last audio stage back again to see if this was important.

UPDATE 1010z: Something is wrong. On the 10FT8R RX no spots, yet when I went back to the FT817ND spots right away. Some spots were strong. I must be doing something stupid. More investigation needed.

UPDATE 1206z:  9 spots so far.

UPDATE 1411z: I have put back the final audio stage on the 10FT8R RX and the spikes have gone (no idea why) and I am spotting lots of stations again with this little RX connected to my indoor loop. At the moment this is the RX being used on 10m FT8 RX. So far, since reconnecting it, 20 stations spotted.

10FT8R RX - even simpler?

At present, I am experimenting to see if I can omit the last audio stage. There seems to be plenty of spare audio. Being a DSB design, it is inherently 3dB down in sensitivity, but that has not been an issue hitherto.

See https://sites.google.com/view/g3xbm4/home/hf-mf-and-lf/homebrew/10ft8r-rx.

10m FT8 RX with the 10FT8R and tiny loop

At 0930z, I turned on the homebrew 10FT8R receiver and the tiny indoor loop. Just M0NKR (27km) spotted so far.

UPDATE 1208z: 7 stations spotted so far today.

10m FT8 RX again

Once again, I am monitoring 10m FT8 RX with the 10FT8R and the tiny indoor loop antenna. No spots yet at 0759z.

UPDATE 1119z: Just one LA spotted so far today. An EA7 did not get uploaded to PSKreporter for some reason.

UPDATE 1230z:  Just 3 spots so far today. 

More on the 10FT8R RX

This afternoon, using the very slightly revised circuit (thanks for the circuit simulation Jay) I have been receiving yet more Es signals on the 10FT8R receiver with the tiny indoor loop. 22 stations just copied in southern Europe.

UPDATE 1604z:  67 stations spotted this afternoon.

UPDATE 1835z: 135 stations spotted today. 

Stations spotted today

UPDATE 2020z: 145 stations spotted today on the 10FT8R and tiny indoor loop.

Revised 10FT8R circuit - rev c

Attached is a revised circuit. Just 1 part has changed value (470n on the input to the first audio stage). For clarification, the caps feeding the PC mic input are 100n. Just for clarity I have made it clear this is my design G3XBM  R.Lapthorn following the comment below by John Desmond EI7GL.

A proper CAD schematic will follow shortly.

10m FT8 RX with the 10FT8R

It is now 0948z. I have been on RX for about 25 minutes using the 10m 10FT8R receiver with the tiny indoor loop antenna.  So far, just OM0ALE (1431km) spotted.

UPDATE 1014z:  Now more stations being received by Es.

UPDATE 1129z:  10 stations received today so far using the 10FT8R RX and the tiny indoor loop antenna.

UPDATE 1547z:  20 stations spotted so far today. The 10FT8R seems to work well, even with the tiny indoor loop.

UPDATE 2128z: 47 stations spotted today on 10m FT8 RX with the 10FT8R and the tiny indoor loop.

10m FT8 receive (Sunday)

This morning I turned on my 10FT8R 10m FT8 RX with the tiny indoor loop.

UPDATE 1258z:  So far just  G3YMW (19km) spotted. I can't wait to get my "proper" antenna up.

UPDATE 2007z:  Now 93 stations spotted with furthermost PU4JLV (9202km). If you saw this antenna you would laugh.

UPDATE 2122z: 105 stations spotted today on 10m FT8 with the 10FT8R 4 transistor RX. and the tiny indoor loop. Imagine what another 6dB could do!

10m FT8 RX yesterday

Yesterday I was again on 10m FT8 RX with the 10FT8R and the tiny indoor loop. Some Es evident to Italy and the Balearic Isles.

Someone in the USA has suggested a small improvement to the audio stages of the 10FT8R following CAD analysis. I shall try this later.

Early start on 10m FT8 RX

At 0555z I turned on my 10m FT8 RX with the tiny indoor loop antenna. The 10FT8R RX is again being used. No spots yet. 

UPDATE 0906z:  3 spots so far today with the best OZ (Denmark).

UPDATE 1520z:  42 stations spotted so far today with the 10FT8R 10m FT8 RX on the tiny indoor loop. See https://sites.google.com/site/g3xbmqrp3/10grab .

10FT8R Schematic

I am sorry this is hand drawn for now. With my addled brain it is much harder to learn new schematic drawing packages. I thought it better to put up a hand drawn sketch than nothing.  Even doing the schematic by hand was hard.

The inductor next to the crystal was added to pull low cost 14.040MHz crystals down to 14.037MHz. In my case I used a T37-6 core with about 6uH inductance. I DC isolated the connections to the PC mic input.

I use the shack 13.8V PSU, but it will probably work with batteries with lower voltage although I have not tried this. Some resistors may have to change in value.

The Polyakov mixer diodes could probably be replaced with matched germanium ones.

If you can improve it please let me know!

10m FT8 RX again

Once again, I have my 10FT8R RX turned on connected to my (poor) indoor loop antenna. I am monitoring 10m FT8. It was turned on at 0833z.

UPDATE 1258z: Just one European spotted so far today 9A6R (1542km).

UPDATE 1420z: So far today, 5 stations spotted. I really need that outside antenna!

UPDATE 1725z: 8 stations spotted so far.

UPDATE 2110z: 17 stations spotted me today. QRT shortly.

10m FT8 RX

My 10FT8R RX (homemade) for 10m FT8 RX was turned on at 0739z with the indoor loop. Later today I hope to create a schematic for this 4 transistor RX, which works well.

UPDATE 1540z: No spots.

UPDATE 1700z: Just 1 spot so far - G4NBS (22km). I notice David G0LRD has spotted 67 stations today on 10m FT8.

The right antenna helps!

My 10FT8R 10m FT8 RX has just been turned on.

Only now do I realise that all yesterday I had my V2000 vertical for VHF and UHF connected to it and not my 10m loop!! It could account for why I drew a blank yesterday. Doh!  😊

So far (with the correct antenna), no spots at 0929z.

UPDATE 1420z:  4 stations spotted with the 10FT8R RX including 3 in Norway with the furthermost LB5SH (1366km). I think this is Es. 

UPDATE 2110z:  26 stations spotted today with the 10FT8R connected to the tiny indoor loop. I am sure with a half decent external antenna far more would be spotted.