10m Neophyte RX

Today I breadboarded a 10m version of the Neophyte direct conversion RX from a 1988 QST. The Neophyte uses an NE602 as the RF amp, LO and mixer and with the output fed differentially into an LM386 audio amp. In my version I used a single toroid 10m tuned circuit and a free running LC oscillator using the oscillator onboard the NE602. As it was a lash-up, frequency stability was a bit average, but it had good sensitivity and allowed plenty of Europeans to be copied on 10m CW and SSB. I used an 8 ohm LS and there was plenty of audio. Overall I was impressed that something this simple worked so well.

Tomorrow I want to try the same circuit but using an external VFO using a VXOed 14.3MHz ceramic resonator in an oscillator/doubler. I am hoping that the resonator will pull well over 100kHz so that it covers a useful part of the 10m SSB band. The same LO will be used for the DSB transmitter assuming it pulls OK and is sufficiently frequency stable.

Ceramic resonator VFOs

David W Searle ZL3DWS sent me a very useful link about the use of ceramic resonators in VFOs. These can be pulled more than crystals but the pulled stability is still better than a VFO. I am trying to use these in a mixer-VFO for my 10m DSB rig. See the webpage by Jack Ponton GM0RWU at the address below. I think taking the output differentially from a tuned circuit across the output pins of the NE602 would be better with a simple link winding down to 50 ohms. http://eweb.chemeng.ed.ac.uk/jack/radio/projects/resnote3.html .

A crystal set transceiver?

JF1OZL has some fascinating ideas on his inspiring website. Typical of his wacky ideas is his 20uW TX for 7MHz powered only by the human voice bellowing into a mic. I wonder if a crystal set transceiver is possible using either the rectified human voice (as per JF1OZL) or rectified received RF to power a micropower TX working alongside the crystal set RX? Even a 0.5uW TX could cover miles on VHF line of sight with a beam and generating this sort of power should be possible through rectification of MW and lower HF broadcast stations.

Japan worked from Europe on 6m

Right on schedule the path across the pole from Europe to Japan has opened up on 6m again this late spring, at least for well equipped high powered 6m operators. The distances are amazing (around 10,000kms) yet this path opens up most (every?) year at this time. Whether or not this is really multi-hop Es is very debatable. Once again it proves there is still much we do not understand about HF/VHF propagation. Amateur radio is continuing to add to scientific knowledge.

Now, wouldn't I like to work JA on 6m with my vertical and a few watts!

10m (and 15m) DSB rig ideas

The GQRP club sell xtals for 24.906MHz for £2 each. They also sell 3.58 and 3.68MHz ceramic resonators at 50p each. Now, mix 24.906 with either 3.58 o 3.68 with an NE/SE602 and you end up with a stable and simple mixer-VFO (when the ceramic resonator is pulled in a VXO) covering two very useful parts of the 10m SSB band or the 15m SSB band. All it needs is a filter on the output to select 10m or 15m injection. I have ordered the xtals and ceramic resonators and will start on the mixer-VFO when the parts come.

My idea is to use the VFO with a simple DSB TX and DC receiver. Such an arrangement will give a simple 10m (or 15m) DSB transceiver covering very useful parts of either band, but with few parts.

Antennas for 6m DXing?

Dave ON8WW sent me an email asking me about what antenna to use for 6m DXing. I replied saying that all I had on the band was a triband vertical colinear (the Diamond V2000) but this has allowed me to work over 50 countries on the band with QRP SSB/CW (best DX >5000kms). It is mounted just above the guttering at about 7m above ground level.

6m is an odd band in that there is not a lot of local SSB traffic (I think) and when the band does open up for either Es or F2 propagation the polarisation probably doesn't matter. Certainly I am able to work (at least) as much DX with the vertical on 6m as I used to work with a rotatable horizontal dipole. The antenna works very well for local (and DX) QSOs on 6m, 2m and 70cms FM of course.

OK, if you want to work marginal propagation modes (e.g. MS using JT6m) or tropo DX then a beam would help. But, if you are prepared to go DX hunting when the band is open, then I think a simple vertical is all you need.

10m/6m Sporadic-E update

It usually happens about now: after the first few weeks of frantic Es activity on 10m and 6m working around Europe (after months of silence), activity starts to drop off. The band is open to somewhere but people are less interested in working you unless you are a new country.

The next excitement is looking for more distant Es openings - into the Middle East, North & South America and the Caribbean. So far this year I've yet to hear a transatlantic opening on either 10m or 6m, but it is still quite early, so I remain hopeful.

Monitoring Monthly - gone

Monitoring Monthly, the UK magazine catering for SWLs and scanner enthusiasts, ceased publication last month with May 09 being the last edition. Their website is still in place for electronic copies to be retrieved.

One wonders, in current market conditions, how well (or not) some of the other ham radio and SWL magazines and ham equipment traders are managing. Anyone know?

LA1TPA - a fellow QRPer

Just got this nice email from a fellow QRPer, Mads LA1TPA, from Norway. Mads, I hope to work you soon on HF or 6m QRP. In this part of the UK there are no mountains to climb with the highest being less than 150m! There are a lot more in the rest of the UK though and I think SOTA is a great idea.

Hello Roger
My name is Mads and I'm a Norwegian QRPer. I'm writing you to tell you that I really enjoy reading your Ham Radio Blog. I got my licence in 2005 and my main interests are Summits On The Air activations and QRP DXCC hunting. I also write a QRP Blog myself: http://la1tpa-qrp.blogspot.com/. I'm a G-QRP member and attended the Rishworth convention last year and also intend to go there this year. Hope to work you 2-way QRP one day.

72
Mads LA1TPA

6m PSK31

Just heard CT1ESJ working an ON station on 6m PSK31. Not thought of using this mode on 6m, but it could be pretty useful for working DX on the band. Certainly the PSK31 area around 50.250 was quite quiet.

Incidentally, I was using Pocket-Digi on my Dell Axim PDA to do the decoding just picking up the signal from the loudspeaker.