My 10m WSPR system has been running most of the day with powers between 500mW and 2W. The only reports were from 4X1RF at 3519km. Best DX station copied here was DU1MGA at 10710km.
One of the reasons I like WSPR is that you can do other things at the same time whilst checking on how propagation is changing. I am really looking forward to running WSPR in the quiet sunspot years on 10m and expect far more openings that might be found by calling CQ on CW or SSB with 5W.
6 May 2013
New QTH work
New QTH rear garden - with the "roof tile feature"! |
I am still thinking about ideas for antennas. At least in the new QTH I will have a dedicated shack where I can both build and operate: in 37 years at the current QTH this has not been possible. Currently I have called off the plans for VHF/UHF SSB/CW/data operation as I don't think there will be enough activity. So, an effective, neighbour friendly stealth antenna for the higher HF bands and 6m will be the immediate priority.
ISWL
Back in the 1960s, when in its heyday, I was a keen member of the International Shortwave League (ISWL). In those days its membership was measured in thousands from all over the world.
A few years ago I rejoined and enjoyed the monthly magazine called Monitor. I contributed a few articles too. Sadly, membership has been declining steadily and now, I believe, the membership numbers fewer than 300 people. The club keeps going as a result of the dedicated hard work by its voluntary staff who put together the magazine each month.
This last year I have started to take the magazine as a .pdf copy. It really isn't the same as a paper magazine you can take to bed and flick through. I find the pdf version much less satisfying.
After some thought, I've decided not to renew my subs this time as it is surely now only a matter of time before the ISWL folds. It served its purpose in its day, but those days have passed. This last month a final coffin nail was the closure of the ISWL QSL bureau, one of the last to process broadcast QSLs as well as amateur ones.
A few years ago I rejoined and enjoyed the monthly magazine called Monitor. I contributed a few articles too. Sadly, membership has been declining steadily and now, I believe, the membership numbers fewer than 300 people. The club keeps going as a result of the dedicated hard work by its voluntary staff who put together the magazine each month.
This last year I have started to take the magazine as a .pdf copy. It really isn't the same as a paper magazine you can take to bed and flick through. I find the pdf version much less satisfying.
After some thought, I've decided not to renew my subs this time as it is surely now only a matter of time before the ISWL folds. It served its purpose in its day, but those days have passed. This last month a final coffin nail was the closure of the ISWL QSL bureau, one of the last to process broadcast QSLs as well as amateur ones.
Labels:
iswl
4 May 2013
The £20 DECENT HF transceiver challenge
Ideas for the £20 (or less) new HF transceiver so far, based on past experiences:
GQRP club sales offer some very good prices for components if you are a GQRP Club member. If you are not a member then you are missing out on the very best magazine (SPRAT) available. I cannot recommend SPRAT and the GQRP club highly enough.
- VXO controlled, single band- GQRP crystals are inexpensive, but will allow around 10-15kHz easy pulling on 14MHz, more on 21 or 28MHz.
- Single balanced diode RX mixer - homebrew with low cost diode and toroid matching
- 2N3904s everywhere - these low cost (5p or less), ubiquitous transistors work well as oscillators, PAs (if several paralleled up) and are OK in audio stages. Maybe an IRF510 PA if a lower HF band chosen,
- Deadbug build - on a small piece of copper laminate and low cost using a few MeSquares to help ease construction
- Low cost metal box - e.g. Maplin Aluminium box or a diecast enclosure. A mint box would be less expensive but too small.
- Few controls - a 1k pot for RF gain is all that's needed on RX
- Capable of running from a PP3 9V supply or external 12v - rechargeable 9V packs are low cost from 7dayshop. 69p each non rechargeable and £2.60 for a rechargeable one.
- Low-Z stereo headphones will be less expensive than a crystal earpiece these days - may need an extra audio stage but at around 10p for this, this is a price worth paying.
- Probably CW, although DSB not out of the question.
- No ICs at all - these are too expensive (maybe an NE602 might be cost effective and I'm not sure about a low cost IC for the RX audio).
- TX-RX offset essential - so that listening on the actual TX frequency is possible
- Does not have to be pretty - the aim is a transceiver that can be thrown in a rucksack and survive reasonable abuse levels.
- Wire antenna - a simple dipole or end fed half wave.
- At least 2W RF out, ideally 5W - so that the rig has a reasonably good chance of being heard on a busy band
GQRP club sales offer some very good prices for components if you are a GQRP Club member. If you are not a member then you are missing out on the very best magazine (SPRAT) available. I cannot recommend SPRAT and the GQRP club highly enough.
Labels:
low cost,
qrp,
transsceiver
Back home again
In all, not that many hours of actual operation in between just relaxing and enjoying the very best part of England. I say this as this is my "promised land", where I was born and brought up. Out of season, when there are few tourists around and in weather like we had last week - perfect wall-to-wall sunshine - there is honestly no better place on this planet, but then I am biased.
My video, taken yesterday, shows the town of Salcombe in South Devon where I lived until I was 10 years old. In those far off days I took all this for granted: I knew nowhere else really. The view from my junior school window was up the beautiful estuary and the sunlight playing on the water would reflect on the classroom wall. Sunny days indeed, long before ham radio and the worries of adulthood.
Now I'm back home my challenge is that £20 (all new) portable backpack transceiver with decent performance that I've been challenged to design. In between cutting grass, weeding and paying the bills!
2 May 2013
Farmyard DXing
A carpet of bluebells on a Devon woodland walk today |
Labels:
qrp portable
1 May 2013
More seaside DXing today
Location today at Rock House beach at Thurlestone, Devon |
One thing is amazing when operating from electrically quiet spots: signals just appear out of a silent band, quite unlike the situation at home where the noise floor is always many dB higher. I had no idea how good the noise floor on my FT817 could be!
Another observation is that most DX stations would be workable 2-way (with 2W) but it is the competition in pile-ups that causes the problems most times. On WSPR, all stations have an equal chance of being copied or copying DX stations, so this gives a much better idea of real propagation with low power.
QRP DXing from clifftop and coastal sites is great fun, but it is more of a masochistic rat race in the last analysis. A few days is fun, especially in the lovely sunshine. More than that I'm not so sure. When I told my wife that I wasn't getting too many contacts as other people were using much more power and got heard first she said, "why don't you use more power then?". Hmmm.
Labels:
clifftop,
devon,
dxing,
pedestrian portable,
qrp
30 Apr 2013
Moorland DXing
Base loaded whip and battery operated FT817 on Dartmoor |
Labels:
devon dartmoor qrp
29 Apr 2013
DXing on the Devon coast
Thurlestone, Devon |
Labels:
devon,
mobile,
pedestrian portable
26 Apr 2013
TJ2B 4 band HF SSB/CW handheld
Reading Julian G4ILO's excellent blog I noticed he mentioned the Youkits TJ2B 4 band HF SSB/CW transceiver from China. The spec of this little handheld looks most interesting with 2 versions covering a choice of 4 HF bands in each option. Available ready built for just $329 with first shipments due around now. A kit version is also available for $269.
Now, at THAT price, this is a much more interesting little commercial unit to climb up that SOTA mountain or clifftop with!
For many months I've been predicting downturns in the Yaesu/Icom/Kenwood sales as a result of the increase in activity from Chinese suppliers. This is surely just the start.
Now, at THAT price, this is a much more interesting little commercial unit to climb up that SOTA mountain or clifftop with!
For many months I've been predicting downturns in the Yaesu/Icom/Kenwood sales as a result of the increase in activity from Chinese suppliers. This is surely just the start.
Labels:
handheld,
hf transceiver,
qrp,
youkits
Using the KX3 portable?
As I prepare for my West Country holiday with my brother next week, I'm amused to see the QST advert for the Elecraft KX3 in use in very rocky terrain. Why am I amused? Well, there is no way that I'd take a "fully loaded" KX3 costing close to £1200 (in UK prices) up a mountain as shown in the photo!
It is OK taking a 12 year old FT817 or a 6 year old VX2 handheld: if these get damaged it's not be a disaster as I've already had huge value from them. But an investment of close on £1200 is another matter.
Perhaps I am not typical, but if I was to spend this sort of money I would not want to throw it in a backpack, risk dropping it on rocks or in a bog and getting battered and scratched. Also, being a very SMD intensive unit, repair is far from easy or low cost.
A better bet for a really portable transceiver to use in SOTA or other portable operations would be a rugged little direct conversion CW or DSB transceiver built into a strong die-cast case, probably for just a single band. It need not look pretty, just functional. Such a unit could be built to give good performance for under £20 buying EVERYTHING new. If dropped, one could easily fix it when back home. If it even got dropped in a bog and irrevocably damaged it wouldn't matter: just build another one!
No, something is wrong if anyone thinks they have to spend £1200 to climb a hill and enjoy amateur radio. I have no doubt the KX3 is a very excellent radio, but it is too expensive (for me) to use in backpack mode.
It is OK taking a 12 year old FT817 or a 6 year old VX2 handheld: if these get damaged it's not be a disaster as I've already had huge value from them. But an investment of close on £1200 is another matter.
Perhaps I am not typical, but if I was to spend this sort of money I would not want to throw it in a backpack, risk dropping it on rocks or in a bog and getting battered and scratched. Also, being a very SMD intensive unit, repair is far from easy or low cost.
A better bet for a really portable transceiver to use in SOTA or other portable operations would be a rugged little direct conversion CW or DSB transceiver built into a strong die-cast case, probably for just a single band. It need not look pretty, just functional. Such a unit could be built to give good performance for under £20 buying EVERYTHING new. If dropped, one could easily fix it when back home. If it even got dropped in a bog and irrevocably damaged it wouldn't matter: just build another one!
No, something is wrong if anyone thinks they have to spend £1200 to climb a hill and enjoy amateur radio. I have no doubt the KX3 is a very excellent radio, but it is too expensive (for me) to use in backpack mode.
Packing for clifftop operation next week
Operating pedestrian portable in South Devon |
For once the weather forecast is cold and reasonably sunny. Usually when I go back to Devon (where I was born and brought up) and it is raining all week my brother says, "you should have come last week - it was lovely".
Labels:
devon,
es,
ft817,
pedestrian portable
More eBay items for sale
http://myworld.ebay.co.uk/rlapthorn |
The Galapagos book cost £18.99 and is in MINT condition.
The Cinema of Isolation book is a very interesting study about how physical disability has been portrayed in the cinema over the last 100 years showing how attitudes have changed.
22 Apr 2013
23cms omni-directional horizontal antennas?
At the moment I'm still pondering the bands to try at my new QTH in a few months from now. One possibility is 23cms, a band I have never used on TX.
One consideration at the new QTH is antenna (non) visibility and I am anxious to go for "neighbour acceptable" solutions on all bands. For 2m SSB/CW/data I am still minded to use a couple of stacked big-wheel antennas giving around 5dBd horizontal gain. Up above the apex of the roof, this should soon be lost being not that much bigger than a TV yagi. The partly vertical feeder to this will load up on the HF bands as a nice stealth antenna: I have used the coax to my 10m halo as a very effective HF antenna, even on 472kHz despite being only a few metres long.
But what about 23cms? Maybe to just get on the band simply and with an unobtrusive antenna the Alford slot is worth a try? If I understand correctly, these give an omnidirectional horizontally polarized signal with around 10dBd gain. Placed at the top of the mast, maybe above the big-wheel and inside a PVC pipe as a radome, and fed with low loss coax (or with the transverter up near the antenna) this might be enough to work the locals during UKAC contests. Alford slots are popular for 23cm beacons and ATV, so why not for local 23cm SSB/CW activity or for weak signal data modes?
Another possibility would be a big-wheel (or should it be tiny wheel?) on 23cms. This would be about 12cms across only!
The photo above was from an eBay item which sold for around £130 back in April. Is anyone aware of commercially available 23cms horizontal omni-directional antenna?
One consideration at the new QTH is antenna (non) visibility and I am anxious to go for "neighbour acceptable" solutions on all bands. For 2m SSB/CW/data I am still minded to use a couple of stacked big-wheel antennas giving around 5dBd horizontal gain. Up above the apex of the roof, this should soon be lost being not that much bigger than a TV yagi. The partly vertical feeder to this will load up on the HF bands as a nice stealth antenna: I have used the coax to my 10m halo as a very effective HF antenna, even on 472kHz despite being only a few metres long.
But what about 23cms? Maybe to just get on the band simply and with an unobtrusive antenna the Alford slot is worth a try? If I understand correctly, these give an omnidirectional horizontally polarized signal with around 10dBd gain. Placed at the top of the mast, maybe above the big-wheel and inside a PVC pipe as a radome, and fed with low loss coax (or with the transverter up near the antenna) this might be enough to work the locals during UKAC contests. Alford slots are popular for 23cm beacons and ATV, so why not for local 23cm SSB/CW activity or for weak signal data modes?
Another possibility would be a big-wheel (or should it be tiny wheel?) on 23cms. This would be about 12cms across only!
The photo above was from an eBay item which sold for around £130 back in April. Is anyone aware of commercially available 23cms horizontal omni-directional antenna?
Labels:
23cm,
alford slot
Virtual amateur radio systems
http://www.hamsphere.com |
www.qsonet.com |
Huge leap in rechargeable battery technology?
The ExtremeTech website has reported a possible major major (i.e. game changing) breakthrough in Li-Ion battery technology with the headlines: New lithium-ion battery design that’s 2,000 times more powerful, recharges 1,000 times faster
If this turns out to be technology that can indeed be commercialised, then just imagine the possibilities: (1) electric cars with far lighter batteries, or electric car batteries with much greater range, (2) mobile phones with tiny batteries that can be charged in a minute or so, (3) portable HF transceivers that are half the weight of the FT817 but with batteries that last for days between charges.
It all sounds just a bit too good to be true, but I am sure this was no April Fool's joke.
http://www.extremetech.com/wp-content/uploads/2013/04/ncomms2747-f3.jpg |
It all sounds just a bit too good to be true, but I am sure this was no April Fool's joke.
Labels:
battery,
extremetech,
lithium battery,
lithium ion
20 Apr 2013
Optical communications in the 19th century
With the recent upsurge in interest in long range optical communications it is easy to forget that optical data communications over long distances predates radio communications by many years. In those far-off days the data was morse code and the light came from the sun in the form of a heliograph mirror that reflected the sun's rays over long distances in daylight. Keying was usually by tilting the mirror or by keying a grill placed in front of the mirror. See http://www.modulatedlight.org/Modulated_Light_DX/Heliograph.html . Best DX achieved in the 19th century was well over 200km using these methods!
Labels:
helio
Infra-red "over the horizon" tests?
Reading Stuart G8CYW's article on the history of optical communications in the latest RadCom, I am considering repeating my recent NLOS optical test using infra-red (IR) rather than visible light as there may be some advantages with clear air forward scatter propagation by going to lower near optical frequencies. At least IR beams are not visible to the casual viewer, so are less likely to create problems. However, IR can be more dangerous than visible light because the blink reaction that occurs with visible light does not happen. When using high power IR LEDs it is therefore even more important not to look into the beam and to take care where the beam is aimed, especially at close range. Never ever look into the beam at close range.
A suitable IR PIN diode is the SRH203-FA from Osram, widely available on eBay. As you can see from the image, the PIN diode detector has IR filtering (black colour) , so may be usable in daylight with less degradation than would be the case with red LEDs. I already use the SRH213 PIN diode for visible red optical comms.
I am looking for a suitable 1W-3W IR LED and they are available, but I have yet to find one in the 10mm "fat" standard LED package that I use currently on 481THz.
There are 3W IR LEDs available from China that should be suitable. See eBay item 370784927290 for example in the star package. This would be some 10dB more output than I currently use, although I am not sure of the beam divergence which may be greater than with the 10mm package.
Nanowave over-the-horizon experiments are very much like microwaves, except that the test equipment is a GREAT deal simpler!
A suitable IR PIN diode is the SRH203-FA from Osram, widely available on eBay. As you can see from the image, the PIN diode detector has IR filtering (black colour) , so may be usable in daylight with less degradation than would be the case with red LEDs. I already use the SRH213 PIN diode for visible red optical comms.
I am looking for a suitable 1W-3W IR LED and they are available, but I have yet to find one in the 10mm "fat" standard LED package that I use currently on 481THz.
There are 3W IR LEDs available from China that should be suitable. See eBay item 370784927290 for example in the star package. This would be some 10dB more output than I currently use, although I am not sure of the beam divergence which may be greater than with the 10mm package.
Nanowave over-the-horizon experiments are very much like microwaves, except that the test equipment is a GREAT deal simpler!
13.8V distribution board
http://www.hamradio.co.uk/sysimages/origimages/PW-100-1_pr5198_1.jpg |
I see that Martin Lynch sell a Mydel PW-100 4-way distribution board with fuses on each output. Although a similar unit could easily be built, this is not a bad price for a ready-made unit complete with spare connectors at around 30 pounds.
When arranging my new shack I shall have to either buy one of these or make up something similar.
Labels:
martin lynch,
mydel,
pw-100
A walk in the sunshine with the Ventus GPS tracker
As the weather was so beautiful this afternoon (full sun and around 13 deg C) I decided to do a country walk and track my progress using the Ventus GPS data logger bought from Martin Lynch and Sons. The walk was 10.7km and took about 2hrs 34 minutes with a couple of relaxing breaks for a drink and a snack. No ham radio gear was taken this time, because I forgot to charge up my VX2 handheld. Next time, HI. Incidentally Quy was where my optical beacon reached (over the horizon) a few weeks ago. When you walk that far it seems a VERY long way away!
This is a plot of the walk taken with the low cost GPS tracker then plotted with Google Earth.
This is a plot of the walk taken with the low cost GPS tracker then plotted with Google Earth.
Today's walk in the Cambridgeshire countryside |
Labels:
martin lynch,
ventus g730,
walk
My wife's choral concert next weekend in Cambridge
Concert Poster |
19 Apr 2013
Loopy on 10m - first results
This afternoon I managed to catch 10m open and got some excellent spots from 4X1RF with reports as good as -5dB S/N using 2.5W to the small magnetic loop taped to the chair in the bedroom shack. Without doing too scientific a test, the impression I get is the loop is every bit as good as the external longwire end-fed antenna in the garden.
I may move the magnetic loop up into the loft in the coming days to see how it performs there, pre-tuned to the WSPR frequency. Based on results in the bedroom, I would expect it to work well.
Labels:
loop loopy 10m wspr
VHF/UHF take-off at new QTH
This evening I went up to our new, well being newly renovated, bungalow on top of our local "hill" immediately next to the Burwell windmill.
Currently the roof is being re-tiled and there was scaffolding everywhere, so I took the opportunity to climb up a ladder to the roof level to judge the VHF/UHF take-off.
Well, the good news is that even at just above the gutter level there is an excellent virtually unbroken (clear of houses) take-off from the north west all the way around to the south. With an antenna a few metres above the roof apex height, it should have a pretty good take-off in most directions. It just begs me to get some better gear for the 2m, 70cm and possibly 23cm and 3cm bands. We'll see.
I was also checking out optical communications possibilities. At lower heights, the horizon view is obstructed, but I should be able to arrange my optical beacon for cloud-bounce and clear air forward scatter, non line-of-sight, tests with the beacon firing up at around 20 degrees up from horizontal in many directions out towards Cambridge and beyond.
Currently the roof is being re-tiled and there was scaffolding everywhere, so I took the opportunity to climb up a ladder to the roof level to judge the VHF/UHF take-off.
Well, the good news is that even at just above the gutter level there is an excellent virtually unbroken (clear of houses) take-off from the north west all the way around to the south. With an antenna a few metres above the roof apex height, it should have a pretty good take-off in most directions. It just begs me to get some better gear for the 2m, 70cm and possibly 23cm and 3cm bands. We'll see.
I was also checking out optical communications possibilities. At lower heights, the horizon view is obstructed, but I should be able to arrange my optical beacon for cloud-bounce and clear air forward scatter, non line-of-sight, tests with the beacon firing up at around 20 degrees up from horizontal in many directions out towards Cambridge and beyond.
18 Apr 2013
Loopy results on 15m
WSPR results today with 2.5W to 80cm loop in the bedroom on 15m |
Loop antenna in the bedroom (notice the grandchildren's toys!) |
I should have tried magnetic HF loops long ago.
UPDATE 1600: Just QSYed to 14MHz with the loop in the bedroom and power reduced to 500mW and still getting plenty of WSPR reports out to 2600km or so so far.
16 Apr 2013
Going loopy on 10m
Prototype 10m TX loop using 6mm copper pipe |
If successful, the idea will be to put this up in the loft at the new bungalow and use it with WISPY and a small dedicated netbook PC to run 10m WSPR.
Labels:
10m,
28mhz,
loop,
transmit loop
12 Apr 2013
Simple, fool proof 1296MHz transverter?
Thinking about my new QTH on top of our East Anglia "hill" (aka 20m bump) I am wondering if I should consider 1296MHz operation for the first time, if only to monitor/try the band in UKAC contests with relatively local stations. Although I have listened (briefly) on 23cm years ago with a borrowed RX converter, I've never transmitted on the band with any mode.
What I am looking for is a SIMPLE transverter for the band, either a no-tune kit or a simple ready built unit. I have no test gear for this band, which is why I've not really considered the band before. The driver would be the FT817, so any suitable band could be used for the IF.
The Down East Microwave 1296MHz transverter may be a possibility. See http://croatia-microwave.blogspot.co.uk/2010/12/w1ghz-rover-transverter-for-1296-mhz.html for a report of one built.
Incidentally I remember the 23cm antenna I used back in the 1970s with the borrowed converter: it was a 4 element yagi made with 2.5mm silver plated wire. The whole antenna sat in the palm of the hand, but worked well, even indoors mounted on a piece of bamboo cane as the mast! If I remember correctly, the design was in an early edition of VHF Communications, a magazine I subscribed to back in the 1970s.
What I am looking for is a SIMPLE transverter for the band, either a no-tune kit or a simple ready built unit. I have no test gear for this band, which is why I've not really considered the band before. The driver would be the FT817, so any suitable band could be used for the IF.
The Down East Microwave 1296MHz transverter may be a possibility. See http://croatia-microwave.blogspot.co.uk/2010/12/w1ghz-rover-transverter-for-1296-mhz.html for a report of one built.
Incidentally I remember the 23cm antenna I used back in the 1970s with the borrowed converter: it was a 4 element yagi made with 2.5mm silver plated wire. The whole antenna sat in the palm of the hand, but worked well, even indoors mounted on a piece of bamboo cane as the mast! If I remember correctly, the design was in an early edition of VHF Communications, a magazine I subscribed to back in the 1970s.
10 Apr 2013
My first QSL card for a JT9 QSO
eQSL card for JT9-1 QSO |
Labels:
eqsl
Sporadic-E season
We are now approaching the summer sporadic-E season in the northern hemisphere with excellent 10m, 6m and 4m (plus 2m on a few occasions) propagation across Europe, the Middle East and North Africa and sometimes far beyond.
On 6m and 10m it is possible to work out to around 2000 miles quite easily with very simple omni-directional antennas and a few watts by single or multi-hop Es.
With some luck much further is possible: a few summers back I recall the thrill of working the USA on 6m with 2.5W out from the FT817 (via a coax cable with around 3dB loss) to a V2000 vertical. ERP was just over 1W. Of course CW was used for this QSO.
Keep an eye out on these bands in the next few months as you may be surprised what can be copied. Better equipped QRO stations will be working South America, deep into Africa and Japan on 6m. Even when the sunspots don't play ball, we'll still have summertime Es. Half the fun is the surprise openings to distant places that appear and sometimes disappear within a few minutes. At other times the lower VHF bands can be wide open with S9 DX signals for hours and hours.
On 6m and 10m it is possible to work out to around 2000 miles quite easily with very simple omni-directional antennas and a few watts by single or multi-hop Es.
With some luck much further is possible: a few summers back I recall the thrill of working the USA on 6m with 2.5W out from the FT817 (via a coax cable with around 3dB loss) to a V2000 vertical. ERP was just over 1W. Of course CW was used for this QSO.
Keep an eye out on these bands in the next few months as you may be surprised what can be copied. Better equipped QRO stations will be working South America, deep into Africa and Japan on 6m. Even when the sunspots don't play ball, we'll still have summertime Es. Half the fun is the surprise openings to distant places that appear and sometimes disappear within a few minutes. At other times the lower VHF bands can be wide open with S9 DX signals for hours and hours.
Labels:
es,
sporadic-e
RSGB UK VHF/UHF Activity Contests - Tuesday nights
This year I keep forgetting to have a go in the regular UKAC contests every Tuesday evening. Activity in these is usually very good and they are great fun. Last year I went out in the field to a local high spot on both 70cm and 2m and achieved some good results with just 2.5W - remember I only found out the FT817 "3 blobs" setting was not 5W in December! Before moving in to my new East Anglian "hilltop" QTH - well it is 20m ASL :-) - I think I'll have to do some of these contests /P from the new back garden to see how the new location will be on VHF and UHF.
Labels:
ukac
Trying to fix an HP8640B sig gen ....and failing
The disconnected shaft is just to the RHS of the YIG oscillator |
You forget how USELESS 1960s and 1970s designs were in terms of ease of manufacture and repair. To get at the part, it looks like you have to take apart about 1 zillion screws and plastic cog wheels, and all because the designer didn't put the control about 5mm to the left, in which case none of these complicated mechanical arrangements would have been needed! These days, where competition, manufacturing and repair costs matter, the design would not be so unnecessarily complicated. After trying to join the 2 pieces together for nearly an hour, I gave up. In the coming days I'll return the 8640B to its owner and I expect he'll have the manual and the patience to fix it. My eyesight is also not as good as it was and that didn't help.
The tiny Elecraft XG3 signal generator (about the size of a pack of cards) would do all I need (and a lot more) and I think will be a good investment. It also weighs about 1/100th the weight of the 8640B. I am not after a signal generator with professional calibration and noise floor performance, just a simple way of checking the performance of simple receivers.
Unless absolutely necessary KISS - keep it simple stupid. This applies as much to professional gear as to amateur gear. Don't make life harder than it need be.
9 Apr 2013
The KD1JV Survivor 75/80m SSB transceiver
http://www.qrpkits.com/images/survivor04a.jpg |
The specs are:
- ~10W pep @ 13.8V
- 0.2uV receiver sensitivity
- 5 pole crystal ladder filter for selectivity
- 325 or 175 kHz tuning range, selectable at build
- Coarse and Fine tuning controls
- 8 ohm - 500 mW speaker output
- SSB, CW, and, "TUNE" mode
- 50mA Rx current (with optional Digital Dial)
- Inexpensive electret microphone input
- All through hole construction
- Professional silk screened and solder masked pcb
- Full aluminum chassis w/bail, cutout for optional digital dial
- Small size, 6" x 4" x 1.5"
- Assembled weight, w/dd: 330g./11.6 oz.
- 13.8 @ 2A, min. recommended power supply
Labels:
hendricks kits,
kd1jv,
survivor
Waters and Stanton respond on the FT817ND price increase
Today I received an email from Mark Francis, the sales director at Waters & Stanton PLC regarding the price of the FT817ND. You may recall I was suspicious that the price had risen when the Yen was weakening.
Mark explained that they are working to the tightest of margins these days and the price is basically set by Yaesu. He also pointed out that compared with 25 years ago we are getting a lot more for our money reminding me that back then the same money would have bought just a 2m FT290, whereas now we get a multi-band HF/VHF/UHF, multi-mode transceiver.
So, I stand corrected and accept what Mark has said.
I'm still looking around for the best deal on a new FT817ND to compliment my 12 year old FT817 that has been used just about every day since I bought it, but may well buy from W&S if they can match the best UK price.
Mark explained that they are working to the tightest of margins these days and the price is basically set by Yaesu. He also pointed out that compared with 25 years ago we are getting a lot more for our money reminding me that back then the same money would have bought just a 2m FT290, whereas now we get a multi-band HF/VHF/UHF, multi-mode transceiver.
So, I stand corrected and accept what Mark has said.
I'm still looking around for the best deal on a new FT817ND to compliment my 12 year old FT817 that has been used just about every day since I bought it, but may well buy from W&S if they can match the best UK price.
Labels:
waters and stanton,
yaesu
8 Apr 2013
Windows PC bargain
After some deliberation because of adverse reviews I ordered an Asus X101ch netbook from Amazon last week. When it arrived I added a 4GB class 10 SD card running Readyboost, deleted the junk software that was not needed, added MS Essentials virus protection and got going.
Well, for under £170 new I am blown away! This little machine is great: I have already used it for WSPR and had my first JT9-1 QSO with it on 20m just a few minutes ago. Spectran seems to work too. For web browsing it is just fine. The screen resolution and clarity are good. I have not had it slow down once and it has, touch wood, not crashed yet.
In fact my view is this is an excellent little 10.1 inch Win7 netbook for the things I need. Although intended as a second PC for /P use (optical beaconing and VLF in the field) it is currently being used as my main PC and working beautifully.
The windows experience index by the way is 3.2, which I think is average.
Well, for under £170 new I am blown away! This little machine is great: I have already used it for WSPR and had my first JT9-1 QSO with it on 20m just a few minutes ago. Spectran seems to work too. For web browsing it is just fine. The screen resolution and clarity are good. I have not had it slow down once and it has, touch wood, not crashed yet.
In fact my view is this is an excellent little 10.1 inch Win7 netbook for the things I need. Although intended as a second PC for /P use (optical beaconing and VLF in the field) it is currently being used as my main PC and working beautifully.
The windows experience index by the way is 3.2, which I think is average.
Labels:
asus,
readyboost,
x101ch
6 Apr 2013
ATV today
Amateur TV seems to be in decline these days with fewer and fewer interested. A well known ATV local G3KKD reports activity well down in recent times.
In a move aimed at reversing the trend G8YTZ has announced some Amateur Digital TV TX and RX modules. However, when visiting Justin's site I was flabergasted by the prices: over £700 for the transmitter and over £300 for the receiver! To attract newcomers surely some simple low cost modules retailing below £100 are needed.
In a move aimed at reversing the trend G8YTZ has announced some Amateur Digital TV TX and RX modules. However, when visiting Justin's site I was flabergasted by the prices: over £700 for the transmitter and over £300 for the receiver! To attract newcomers surely some simple low cost modules retailing below £100 are needed.
Another version of my 472kHz transverter (G8AGN)
Emeritus Prof Barry Chambers G8AGN from Sheffield (more usually a microwaves and nanowaves operator) has just sent me a couple of photos of his version of my 472kHz transverter that he's just finished. Unlike me, Barry sensibly put it in a decent sized aluminium box which will help reduce heat affecting the LO frequency stability.
I've lost count how many of these transverters, or variants thereof, have now been built but there must be a good few in use around the world now. I have still to box up the 137kHz version which was used a few months ago to span 250km with just the earth-electrode antenna.
G8AGN's version of the 472kHz transverter |
Labels:
472khz transverter
4 Apr 2013
Japanese Yen and radio gear prices
Today alone the pound-yen exchange rate has improved by over 4% in favour of the pound: basically Japanese goods are 4% cheaper than yesterday. UK dealers, please note: your customers are expecting product prices for Japanese radios to FALL please in the coming days and not rise!
The yen-pound exchange rate is now around 23% better (for purchasers of Japanese equipment) than a year ago, so some VERY good deals should be expected on Yaesu, Icom and Kenwood products.
The yen-pound exchange rate is now around 23% better (for purchasers of Japanese equipment) than a year ago, so some VERY good deals should be expected on Yaesu, Icom and Kenwood products.
3 Apr 2013
A couple of 20m JT9 QSOs in the log already
QSO with UA4PPQ on 20m JT9-1 today |
The mode certainly seems to be very useful on HF and takes up very little bandwidth - the scale on the screenshot above is in Hz above 14.078MHz, which is the USB dial frequency.
Using 2.5W to the end fed Par 10/20/40 antenna, but reports suggest much lower power would be fine too. Now QSYed to 28.078 MHz USB dial JT9-1 and calling CQ.
Labels:
jt9,
jt9-1,
weak signal modes
JT9 mode on HF
Julian G4ILO has been having some good success on HF with JT9 mode, so I am encouraged to have a go too. This afternoon I'll be firing up on HF, probably 20m.
Results with this mode on MF were very encouraging giving me my first international 2-way QSO (as opposed to WSPR report) some months back. The slower JT9 modes are similar to WSPR in terms of weak signal performance, but allow basic real 2-way QSOs similar to JT65 mode QSOs.
PSK reporter now shows JT9 spots, so it is possible to see where your signal is reaching even if a QSO does not result from a CQ call. The new JT9 Yahoo group is rapidly gaining members and is worth joining if interested in this new mode.
Recommended JT9 mode frequencies are:
10m 28.078MHz
15m 21.078
17m 18.104
20m 14.078
30m 10.130
40m 7.078
60m 5.2872
80m 3.578
160m 1.838
JT9 software can be downloaded from http://physics.princeton.edu/pulsar/K1JT/ As updates are still occurring it is best to check the site for later versions regularly. The user guide for all WSJT modes is worth reading.
Results with this mode on MF were very encouraging giving me my first international 2-way QSO (as opposed to WSPR report) some months back. The slower JT9 modes are similar to WSPR in terms of weak signal performance, but allow basic real 2-way QSOs similar to JT65 mode QSOs.
PSK reporter now shows JT9 spots, so it is possible to see where your signal is reaching even if a QSO does not result from a CQ call. The new JT9 Yahoo group is rapidly gaining members and is worth joining if interested in this new mode.
Recommended JT9 mode frequencies are:
10m 28.078MHz
15m 21.078
17m 18.104
20m 14.078
30m 10.130
40m 7.078
60m 5.2872
80m 3.578
160m 1.838
JT9 software can be downloaded from http://physics.princeton.edu/pulsar/K1JT/ As updates are still occurring it is best to check the site for later versions regularly. The user guide for all WSJT modes is worth reading.
1 Apr 2013
Good communications , or a lack of it in the NHS
My ham radio friend Julian Moss G4ILO has a brain tumour which he has been
successfully battling for over a year now. Recently he had a hospital
appointment to review treatment but reading his blog
I see yet again he has, like many I know, been given the "run around"
by the totally inept NHS service here in the UK.
This organisation needs radical surgery to get itself operating efficiently. Time and again it wastes money by messing up appointments, not having people where they should be, not having the data communicated between staff etc. It MADDENS me that sick people should be additionally stressed as a result of idiots who cannot run a business properly. They would save BILLIONS if patient records were shared electronically between health care staff (consultants, doctors, nurses, car service personnel and ambulance crews). It is not rocket science.
I have no fundamental issue with caring people trying to do their best, but they are totally hindered by the lack of decent communications at all levels.
In the 21st century, any organisation as bad as the National Health Service today would be in administration by now and its bosses sacked. NHS sort yourselves out!
This organisation needs radical surgery to get itself operating efficiently. Time and again it wastes money by messing up appointments, not having people where they should be, not having the data communicated between staff etc. It MADDENS me that sick people should be additionally stressed as a result of idiots who cannot run a business properly. They would save BILLIONS if patient records were shared electronically between health care staff (consultants, doctors, nurses, car service personnel and ambulance crews). It is not rocket science.
I have no fundamental issue with caring people trying to do their best, but they are totally hindered by the lack of decent communications at all levels.
In the 21st century, any organisation as bad as the National Health Service today would be in administration by now and its bosses sacked. NHS sort yourselves out!
Labels:
national health service,
nhs
Tripods for optical comms
The one I missed on eBay |
So, can readers make any recommendations for something similar?
My requirements are:
- Solid construction so it won't wobble around in wind with the optics and detector mounted on top.
- Some way of calibrating the direction to within a degree or so horizontally so that known directions can be confidently returned to. Ideally a large 360 degree marked scale.
- A way for leveling the head assembly so it can be aimed just above the horizon.
- Low cost as I am looking for an inexpensive solution (don't want the tripod and mount to cost much more than the rest of the kit, which is about £5-10 total!)
Labels:
optical 481THz,
tripods
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