50W red LEDs cheap on eBay

Bernie G4HJW recently posted to the UK Nanowave Yahoo about some powerful red LEDs that he bought from China for just £2.80. A couple of these are more powerful than the 10mm LEDs that I used in non line of night tests (when I was fitter) but even without any lenses!  It would seem these would be ideal for optical tests. 50W is a lot of power. This was Bernie's post. I trust he won't mind me sharing it with you all:

"Morning all - This might be of general interest:

I recently bought a couple of 50W red LEDs from China, which I thought I might use in a wide-angle initial set-up lantern for portable use. They were very cheap (£2.80), so I also expected there would be dead segments, which there were, but there was a bigger surprise waiting to show itself.

During this weeks UK uwave group net, Martyn G3UKV asked me how wide the spectrum was, so out came my trusty secondary school Spectroscope. Instead of the expected relatively narrow response, there was noticeable output right through to yellow plus a weakish narrow line at the violet end. This should have been an obvious clue, of course, but it was only later when I was telling Stuart G8CYW (sorry about all the name dropping..) that he suggested  that the LEDs might be fluorescent driven devices, just like the white lighting LEDs all seem to be these days. He was correct, as the following picture shows:

http://www.earf.co.uk/uvred.JPG

Note that in pealing back some of the fluorescent gell, all but one of the individual 1W UV leds have been destroyed. Not obvious from the picture is that these LEDs are embedded in an initial clear silicon rubber prior to the red fluorescent layer being applied. From supplier ebay pictures, it is now clear that the same UV driven devices are available in all colours, leading to the question - does this produce an overall increase in efficiency, or is there simply a significant cost saving in just fabricting UV LEDs?.

I've yet to measure the response time of the fluorescent material.

Bernie
G4HJW"

Working with simple optical gear was one of my great pleasures, so I very much hope I can do this again. Optical gear is easier than microwaves. All my kit was home designed and built and the test gear simplicity itself.  For details of my optical work see http://www.g3xbm.co.uk  . G4HJW and others know far more than me in this area. I consider myself very much a novice in this area.

IC7300 video

This video is available on YouTube. It is an in depth look at this new ICOM IC7300 transceiver.

Sunspots and 10m - Mon April 4th 2016

Solar flux is 82 today and sunspot number higher at 38 (K=3).  The forecast for 10m propagation is still "poor" but 10m looks a little more promising than yesterday, which was dire here.

I am about to switch on 10m WSPR.

UPDATE 1735z:  No 10m WSPR spots all day.

Redgrave and Lopham Fen, Suffolk - NOT amateur radio

River Waveney

A few weeks ago a friend very kindly gave us a pack of "Easy Going Trails" in Suffolk. She thought I might like them. So far, we have done 3 of these.

Marsh Margolds

Today we went to Redgrave and Lopham Fen which is located about 3 miles west of Diss. I have yet to work out how far I managed but we saw or heard lots of birds including snipe as well as seeing several Konig ponies and marsh marigolds. It was a round trip of 73 miles in the
car. Although I enjoy the walks, I get very tired by the end.

QRP

More from Oleg:

Dear Club 72 members and friends,
See  full  QRP  Rendez-Vous weekly report (March 28 to April 3, 2016)
including   comments  and  picture  at  the  Club  72  blog  page  - http://qrp-club72.blogspot.ru/
Visitors  of  week:  HB9DAX,  UR7VT, EA5IGL, DL6YAU, HA5AZC/p, RV3GM, UA1CEG/p,  UR0ET,  ON6KZ,  RU3NJC,  EW1CY,  R6TQ, F8DGY, OH5LP, R1OA, GM3OXX,  RD7K,  OM6TC,  OK1KW,  UA1ADF, R4NX/p, UA4NU, UA1CEX, SM6NT, UA1ASB,  DL4HG,  RA1M, OH6NPV, UA0SBQ, UR4MME, LY2H, MM0CYR, EA2AO/m, R4AAR, RW3AA, EA8YV, G6HUI, OH7QR
See full Visitors and Frequenters lists at - www.club72.su
Schedule of QRPRendez-Vous "round tables" on the Club 72 page.
QRP   Marathon  "Look  In  the  Horizon"  is  continue now. To become
Marathon'ers  visit  Club  72 page and create account on the Marathon
page.  You  can do it during all April. Enjoy QRP and have a Marathon
certificate in May.
72! Oleg RV3GM / KH6OB "Mr. 72"

Fair well - NOT amateur radio

Our best man 45 years ago (we married in 1971) has left after a few days with us. He is a good friend and guest and we always pick up as if we saw each other just yesterday. He live 200 miles away and it is often 6 months or more since we last met.

Here he is packing his car outside our home standing next to my wife.

G3XBM Projects

Yesterday, Steve G1KQH mentioned in a comment how he missed my projects. I do too!

As many will be aware I suffered a stroke 2.5 years ago. I expected to make a full recovery, but it has not worked out that way. Even now, although people tell me how well I look, I still feel giddy most of my waking hours and I tire easily.  My voice is poor and I have trouble with drinks. My fine motor skills are not good. Basically, I have struggled with things that were easy in the past. I really miss just fiddling and building. Life is much harder.

Sunspots and 10m - Sun April 3rd 2016

Solar flux is 81 today and sunspot number 11 (K=3). Conditions look a little worse than yesterday. The forecast for 10m propagation remains "poor". Although  I am expecting little, this band has a habit of throwing surprises.

10m WSPR

For the last 30 minutes I have been back on 10m WSPR.  I hope 10m is as good as yesterday, which was very good on WSPR despite the low sunspot count and declining solar conditions.

WSPR is excellent in the declining 10m conditions. If there is a brief opening it will be found on 10m as long as people continue to use the band and mode. 10m is often open when the band seems dead. My strong recommendation is use WSPR. It only needs low power and can be run in the background. Using 10m WSPR really helps radio science.

UPDATE 1035z:  No 10m spots as yet.

UPDATE 1220z:  Still no 10m WSPR spots.

UPDATE 1900z:  Just G8VDQ (93km) spotted lunchtime aided by aircraft reflection. No DX at all today here on 10m. After yesterday, a really disappointing day.

A brilliant day on 10m WSPR

Despite the low solar activity, today turned out to be a good day on 10m with spots of stations in North and South America as well as European short skip. I was spotted in the USA. And I was expecting to copy nothing today!