Fredbox derivatives

Since my original Fredbox 2m AM design, a number of derivatives have been designed and built around the world. This is what our hobby is all about. Although the original Fredbox worked well and its results surprised me, it was always ripe for further developments, which is healthy. My Sixbox was a 6m version and at some point, when fitter, I'd like to make a simple 10m AM version for local natters.

See https://sites.google.com/site/g3xbmqrp3/vuhf/fredbox for the original Fredbox. Click on the schematic to enlarge. Other derivative ideas are on my website www.g3xbm.co.uk.   By the way, it got its name from Fred G8BWI who was a disabled local in the Cambridge area back in the 1970s. Fred was a regular contact and he could talk for hours and hours and hours and hours zzzzzzzzzzz. RIP Fred.

Stroke update

Last year I was expecting to be fully back to my old self well before now. As it is, I am still some way from that position.

Overall, I think I am still improving, but the big leaps I was expecting don't seem to be happening. Perhaps I should be satisfied with slow, small, moderate steps?  

I still feel as if I am living in a bit of a dream world, I still feel drunk when walking (feel giddy), still tire easily, and drinking thin liquids is still not easy.

Overall, I am getting slowly better, but perhaps I should expect to be left with a level of disability and will be pleasantly surprised when I get fully fit again. Perhaps my expectations were unrealistic? Whatever, I am not giving up: I want my "old self" back again this year.

At the moment I still feel unable to do field work, climb ladders (for antenna work)  or use a soldering iron. With time, this will improve.

Sunspots up again

Sunspot number today has risen yet again. It is 140 today. 10m is expected to be "good".

4X1RF (3519km) was copying my 10m 500mW WSPR beacon at 0924z. I remain hopeful of greater DX this morning. 10m should certainly open to North America after lunch. This happens on most days.

433MHz AM modules - G6ALB progress

G6ALB has reported some progress in his tests using 433MHz AM modules, although it looks like an external linear audio transistor stage may be necessary to get best AM (voice) sensitivity from the super-regen detector. On TX he is getting 10dBm from the TX module at 5V (more with higher supply voltages) although the mod seems to be a mix of AM and FM. Our first "DX" test will probably be from G6ALB to me using the voice modulated TX module. I'll receive Andrew on my FT817ND initially. When the super-regen RX is sensitive with speech I'll try to receive him with that. Super-regens should be sensitive on AM, but are usually poor NBFM detectors.  We are about 3km apart and both have V2000 verticals externally mounted. At 70cms these have gain.

Andrew has ordered 5  pairs of 433MHz AM modules (TX as well as RX) for not much more than £2 total from China. This makes each TX/RX pair very inexpensive. It amazes me that they can make these so inexpensively. I hope G6ALB succeeds in this venture. It would be good to be able to communicate with him using a really low cost 70cm transceiver. I expect Andrew will write up his results in an article for a UK magazine later.

It seems entirely possible that a complete 70cm AM transceiver can be made for just a few pounds based on these low cost 433MHz AM modules.

10m USA WSPR spots

The first USA spot of my 10m 500mW WSPR was K9AN (6505km) at 1352z. The last USA spot was W3CSW (5886km) at 1804z. It is still possible later USA spots may happen, but it is now over an hour, so unlikely.

UPDATE 2056z:   Only local spots since W3CSW at 1804z on 10m WSPR.  Now going QRT on 10m WSPR.

29MHz AM

The 29-29.1MHz sub-band continues to be the best place to find HF AM. This is the HF band with most space, although there are AM enthusiasts on 160m and other bands. When these bands are not busy AM has its place.

When 10m goes "off the boil" 29MHz AM will be ideal for local nets with very simple gear. Ranges are fine for local nets. Also there is a ready supply of ex-CB kit around, although making a wholly homebrew QRP rig for 29MHz AM is a nice group project. There are some ideas for starters on my main website.

As an example of how effective 10m AM can be see http://www.macnaughtonart.com/10metlog-ss24.htm .

Sunspots and 10m - Jan 28th 2015

Sunspot number continues to climb and is 119 at present. For the first time in some while, 10m propagation is forecast to be "good". LZ1OI (2153km) has spotted my 10m 500mW WSPR beacon 10 times this morning already. As I write this it is 1046z.

Today could be a good 10m day.

UPDATE 2215z:   Now QRT on 10m WSPR  Although the band did open to the USA after lunch, it was a rather disappointing day on 10m WSPR for me.

50MHz UKAC session this evening

Tuesday nights are the nights for the RSGB's UKAC sessions. Tonight it is the 50MHz (6m) leg. As I only have a vertical omni-directional antenna (a V2000) it is very unlikely I'll work very much.  Add to that my poor voice and it is not a great recipe for too much success! I'll give it a brief try. The contest starts at 2000z and officially ends at 2230z. If I last 1 hour I shall be doing well.

UPDATE 2135z:   3 QSOs managed before I had to go QRT because of my poor voice - all locals. Best DX heard was G3MEH (IO91QS). Of course my antenna was the wrong polarisation.

6m QRP rigs

In many ways, 6m (50MHz) is an ideal band for experiments. Short RF leads are always good, but 6m is a forgiving band and you can get away with HF constructional techniques. It is 2MHz wide here in the UK and this means all speech modes can be fitted and used. The page below shows a number of links to 50MHz projects.

See http://www.pg1n.nl/articles.php?lng=en&pg=145 .

See also my Sixbox 6m AM transceiver .

10m WSPR - USA spots today

Although the band did not open to the USA until very late (1454z), plenty of different USA stations have been copying my 500mW WSPR beacon all afternoon. This is much better than yesterday.

The first spot of me was KZ8C (6290km). At the moment (it is 1805z) I am still being spotted by several stations in the USA.

UPDATE 1945z: The last USA spot of my 10m 500mW WSPR beacon was by K9AN (6505km) at 1902z.