DSB transceiver circuits - 10m and 6m

Michele IZ8JJI has just sent me a link to a neat, very simple, DSB transceiver suitable for either 10m or 6m. It is from a Japanese magazine (CQ?). See http://www.cqpub.co.jp/hanbai/books/15/15061/15061_p.180-181.pdf

I am not sure of the power (milliwatts I think) but WHAT a neat circuit!

Working REAL 10m DX at last!!

After calling for 15 mins I eventually worked LU1HF on 28.010MHz CW this evening by F2 or TEP. He had been calling CQ for over 15 minutes without getting a reply and then he heard my 10W to the wire halo and gave me 599. OK it was a contest exchange, so probably much weaker. I think my antenna must have quite a low angle take-off as working this station, against the rest of the world's competition, shows.This is my best 10m DX for some time at 11077kms. So who needs sunspots (the count was zero today).

A few minutes later I worked ZW5B in Brazil who got my callsign but he then lost me.

At 2138z I worked UU7J in the WPX contest.

6m Lunchbox - further thoughts

Further thoughts on the G3XBM answer to the Benton Harbor Lunchbox for 6m. Maybe it would be better to make the rig DSB instead of AM? The design is almost as easy and a VXO crystal at 25.08 or close would give some 50kHz VXO range (50.15-50.20) in a useful part of the band. Also, it would be more efficient than AM. In sporadic-E openings it would produce some DX contacts too if the power out was around 0.5 to 1W pep.

Cyprus on 10m

WPX CW contest and 10m CW quite lively. Just worked C4I (Cyprus) at 599 with QRP no problem.

6m DX to the Congo

I overheard G4DEZ telling another station that he had worked the Congo on 6m CW today. This is some distance on 6m Es! G4DEZ does have an impressive station and antenna farm but this was with 100W, so no super QRO.

6m Fredbox ideas

Looking at project ideas, I am beginning to think about a simple 6m AM transceiver design. The starting point would be my Fredbox design for 2m AM from many years ago. An outline spec would be: 500mW AM crystal controlled TX, simple superregen RX, built as a small modern day "Heathkit Lunchbox" style rig with an RX tuning knob and LS. Such a simple radio would be an ideal local ragchewing radio and would give coverage up to 10-15 miles with a simple vertical colinear antenna, dipole or halo.

A very good example of a 6m superregen (also regen) RX by N1TEV can be found at http://www.arrl.org/tis/info/pdf/9712039.pdf although this is more complex than I would plan to use.

6m QRPP

Worked M0BXT tonight on 6m AM when Andrew was using a single transistor TX using a carbon mic to produce AM! His signal was RS58 with me at 2 miles range but modulation depth only about 5-10%. Still, it was a QSO.

Good Es tonight

Worked ZB2FK this evening at 2126z on 50.090MHz CW. I think this is a new country for me on the band. 10m was also in good shape with lots of very strong Es DX coming through from Europe and N.Africa.

Microvert antenna

Many people are looking for that magic antenna that takes very little space and performs very well on HF bands. Some examples of this claim include the cross-field antenna, the EH antenna and the Miracle Whip. Now all of these have their place. I have used a Miracle Whip and it behaves as one would expect i.e. several S points down on a full sized antenna, but it communicates. Even decent DX has been worked with one (11000kms on 5W SSB) during the high sunspot years.

This week my attention has been drawn to the Microvert Antenna (see picture of an example). Is this a more realistic attempt at an efficient, small sized HF antenna? This antenna was developed by DL7PE. The radiator for 7MHz is only 1.33 metres long and the counterpoise is 8.2 metres. the 28MHz version is very small indeed. Perhaps this is worth a try? See also the Microvert Yahoo Group.

Multi-hop Es or Es+F2?

Last night, around 2100z, 10m was open to South America by what I assume was multi-hop sporadic-E or possibly Es linked to F2 at lower latitudes. There was strong Es to Spain/Portugal at the time so the latter may be more probable. Stations heard but not worked included YP4DYP, YV5EAH and YV4DYJ all on SSB. Distance is around 8000kms - which is some distance for Es alone.