March 2024 – Page 2

WSPR – weak signal propagation reporter

What is it?

I could go into lengthy detail but I won’t bore you just yet. Below I have quoted the Wikipedia entry that explains things in a nutshell better than I ever could. I will however give a few details of attempts I have made and equipment I use for carrying out this mode of communication. I am currently building a new radio for this mode that I will cover in a later post.

WSPR (pronounced “whisper”) is an acronym for Weak Signal Propagation Reporter. It is a protocol, implemented in a computer program, used for weak-signalradio communication between amateur radio operators. The protocol was designed, and a program written initially, by Joe Taylor, K1JT. The software code is now open source and is developed by a small team. The program is designed for sending and receiving low-power transmissions to test propagation paths on the MF and HF bands. WSPR implements a protocol designed for probing potential propagation paths with low-power transmissions. Transmissions carry a station’s callsign, Maidenhead grid locator, and transmitter power in dBm. The program can decode signals with a signal-to-noise ratio as low as −28 dB in a 2500 Hz bandwidth. Stations with internet access can automatically upload their reception reports to a central database called WSPRnet, which includes a mapping facility.
Wikipedia

What fascinates me most about this mode of communication is that in recent weeks it has gained a new audience as a result of a television documentary. This documentary was regarding the search for the missing Malaysian airways flight MH370 that vanished from radar screens on the 8th March 2014. An investigator tracking its disappearance has been cross referencing WSPR signals in the area that the aircraft was last reported and he has apparently plotted the route taken by monitoring these signals as they were reflected or distorted by the aircraft’s footprint in this area, well beyond the planned flight path.

My setup for testing propagation on a number of different bands is very portable as that’s normally the way I work when taking to the airwaves. I’m always moving around or working from different locations so it’s always good to be able to monitor conditions using a compact setup.

I do also have an aerial system set up in my loft that cannot be seen, it’s kind of clandestine in that way it does not grab the unwanted attention of my neighbours. I specialise in low power communications and again this does not draw the attention of anyone living near by as disturbance and interference rarely occurs. The maximum power level I normally use is 10 watts, but more likely somewhere around the 5w QRP level. My WSPR setup operates between 200mW and 5mW of power. Extremely low power, there is probably more power in that sports watch sitting on your wrist than what I am transmitting.

My Portable setup

I have an inflatable aerial, yep that’s right inflatable! Perfect for mobile operation using QRP low power technology, It covers most of the high band frequencies and I mainly use it on the 20 Mtr band (14mhz) or the 40mtr band (7mhz) though other bands are also available. Fully inflated it stands about 6ft high and can be hung outside, inside or just perched in a corner somewhere.

There is an antenna tuner , this is one I purchased from the States in a kit form and built myself. It’s called an Emtech ZM-2 Atu details can be found HERE

The actual transmitter sits in a small package not much bigger than a box of matches. This was purchased already built and is called a WSPRLITE classic. I am in the process of building a new transmitter and receiver combo that is also in a kit form, I don’t anticipate completing it any time soon as I just don’t have the time at the moment.

I have made a number of filters for the different bands (40mtr, 60mtr,80mtr and 160mtr) and these boards connect to the output of the transmitter to aid in obtaining a clean signal and to prevent deviation from the set frequency.

The power comes from a 3000 mAh 5v power bank. However the problem here is that the power draw from the WSPR unit is so small the power bank will some times close down, and for this reason I have had to build a small usb circuit that creates a minimal demand on the power bank keeping the power supply constant. With this power bank and the WSPR unit on its high setting I can easily get 16 hrs of continuous use. When I work on the lowest setting I can achieve 3 full days (72hrs) of use.

And that’s about it, all this kit can fit in a small unobtrusive bag or box.

Operation

First and foremost the transmitter connects to a computer where you can access all the parameters of the unit and set it up how you want your operate, power, duration and frequency etc. The unit already has inbuilt filters for the 20mtr (14Mhz) band so you don’t need additional filters if that is your band of operation. Once the programming is done you can now set the system up in place as you want it. I sometimes use this from my loft to see just how well certain bands are working in certain directions at different times of the day.

The battery connects to the transmitter that in turn connects via the filter to the Antenna tuner unit. the antenna unit connects to the antenna.

Timing has to be precise when setting up, you set it to transmit at every 2 minute interval.

Once you are transmitting it’s worth leaving it be for about 30 minutes and then you can pop on to WSPRnet to check your signals. You can check what is being received and what strength of signal is getting through to your destination .

I use an app called WSPR watch that connects via the WSPRnet system so I can monitor my performance from absolutely anywhere just by using my mobile phone or iPad. How convenient is that? I can leave the unit unattended and monitor it remotely.

In summary the WSPR protocol uses a very weak signal to test atmospheric and solar cycle conditions to determine a viable route for a signal to reach a destination. if you were to listen in at the destination all you’d probably hear is white noise, however the decoding program is so accurate it can pick up a signal to noise ratio of as low as -28db.

Im leaving it there as I could ramble on for ages. If anyone for some strange reason wants to know more then please get in touch.

Thoughts 21/3/24

What do you wish you could do more every day?

I really wish I could participate in all those things that I love to do on a daily basis. The only problem is as I’ve always stated is that Work gets in the way of everything I enjoy doing.

I can’t understand how many people go into retirement and have nothing else to do. I work in a business, where the employees are so use used to working a regular shift based timetable that they become so ingrained with the work ethic, retire and very shortly you are attending a funeral.

I know that sounds a bit exaggerated but that’s the way it seems to anyone who retires from this job, it is as if they are now entering the corridor to the end of their days, strange i know but we’re so used to it when someone says they’re going to retire we all think the worst.

I don’t want that to be the same for me. I have so many interests that I can never see myself being bored or getting to the point that I just sink into being happy with my lot.

In a nutshell hobbies that’s what I would do.

Have a good day folks stay safe. Be happy.

Thoughts 19/3/24

What is one word that describes you?

Introverted

I used to work in Customer services years ago for some globally recognised brands and institutions. I struggled at times in the role and it was only when my wife was bluntly open with me that I realised the issue. “You know your problem, you just don’t like people”.

Though not totally true it made me think, I don’t like crowds of people to be honest and I can count my trusted friend on the one hand, I like to keep my pack small, and upset me and I’d drop you without a second thought.

I’d say I was an Introvert.

An introvert is commonly characterised as someone who is quiet or reserved, and an extrovert as enthusiastic and outgoing. Introverts may sometimes avoid social situations or engagements in larger, unknown crowds in the fear that they will be left feeling drained and mentally exhausted
Raw Eden Beauty

The quote above is from a person who sees it just the same way I do. I work as a one man mobile trouble shooting team for my company now and that suits me down to the ground. I get things done and I like to think I do it well.

I don’t like uninvited visitors to the door, I see this as an invasion of my privacy, and this puts me at odds wife my wife as she is my polar opposite. She is gregarious, sociable and totally outgoing, all the things I am not.

She puts up with me and my ways. We’ve been a team for over 35 years now.

Maybe there is truth in the saying “Opposites really do attract”

Thoughts 18/3/24

What was the best compliment you’ve received?

I’m sure I’ve received some compliments in the many years I’ve been walking this big old world.

I’m just one of those people that doesn’t seem to register compliments when they are given.

It’s as if I prefer to constantly question myself and my abilities, and react with disdain towards anything complimentary.

Strange isn’t it? I’m sitting here really trying to think of a moment in time and then one does pop into my mind…

My mother on her death bed holds my hand, looks at my wife and I any says, “You are a lovely couple”.

Maybe that’s why I struggle with it all. She was the best and nothing can ever trump that moment in time. Maybe I’ve locked the door to compliments from that moment on, who knows?

It is strange isn’t it?

More cameras to keep me busy

Did I overpay?

I have just purchased 6 untested ( probably the polite way to say totally useless) cameras from the late 80s.

I ended paying out the equivalent of £6:17(GBP) per unit. That’s inclusive of delivery and costs as well, not too bad really and if I can repair (if needed) I should still be able to move them on at a small profit. But I may also be passing these onto a local charity that teaches photography to youngsters and disadvantaged people in Leicestershire.

I have purchased a job lot of Canon Eos 650/600 cameras from quite a reputable seller who specialises in old film cameras.

I have 2 Canon Eos 600 units that date from 1989. These have motorised film advance and rewind, and are able to reach 5fps in one shot Af mode. Shutter speeds range from 30 sec to 1/2000 sec, with B mode. X-sync is at 1/125 sec. Powered by 1x6v 2CR5 lithium battery.

I also have 4 Eos 650 units.

The Eos 650 is the camera responsible for the first photograph used on the World Wide Web when a photo of the band “Les Horribles Cernettes” was taken on 18th July 1992 by photographer Silvano de Cennaro.

This camera was produced in 1987 and was the first of Canons Eos (Electro-Optical System) ushering in a new era for Canon cameras. The shutter is electronic, vertical metal focal plane capable of 30 sec to 1/2000 sec exposures as well as having 1/125 sec exposure with a flash. Also powered by 1x6v 2CR5 lithium battery rated for up to 100 36 exp rolls.

Both types use the Canon EF mount.

I’m happy from the pictures and knowing the sellers reputation that these units are cosmetically tidy, fingers crossed they don’t need a great deal doing on them but you never know. When they arrive I will do an assessment of both cameras and create a post accordingly.

Until then stay happy, stay safe and take care.

Sony Discman D-141

Assessment and fault finding….will it work ?

Double trouble here as I’ve purchased two of them.

These variants are from 1994 just around the height of the capacitor plague problem. As I’ve already dealt with a D-121 version this week that was riddled with the issues and being only a year older, I’m not too hopeful that these two will be any different. They both have the same issue being that they turn off after about 10 seconds, this could be due to a number of issues, let’s get them unpacked and get an initial inspection done.

On initial inspection they both appear to be quite tidy considering they are 30 years old. One is missing a disc capstan however i do have a replacement from the old D-121 that was added to the spare parts box earlier this week.

Both start up, spin and then stop, sometimes showing a no disc error, sometimes not. The good news is there is no sign of corrosion on either unit.

Time to open them up….

I used the old donor D-121 from earlier in the week to replace the missing capstan on one of the units.

On opening of the cases the boards looked ok. No signs of corrosion or plague damage, this was a good sign and it was now time to look a little deeper.

I did the standard clean of the lenses with IPA, I re greased the worm gears and rails but none of this alleviated the issue of the discs stopping just after start up. I did some continuity checks and component checks, all seemed ok. All buttons worked, all switches worked, something just wasn’t right. I decided to check the output of the laser adjustment pot and this was extremely low. I spent a good hour on the first unit and a similar time on the second trying to adjust the range up and down before realising that after 30 yrs both lasers seemed to be at fault. No adjustments improved the output.

Faulty laser assembly removed and replaced

I was facing the fact that I’d now have two more failed units to go with the D-121 earlier this week. Then I thought why not try the laser out of that failed unit?

It worked. The D-121 donor unit was compatible with the D-141 and after a few minutes adjusting the laser we were able to play an audio Cd.

We have life

This week I have looked at 4 faulty units and managed to get 2 fully working with a third one needing a replacement laser sled when one becomes available. I have one spare redundant unit that has been indispensable for the repair of the other units, in theory i potentially have 3 out of the four available.

All dressed up

I won’t be wasting anymore time on Discmans in the foreseeable future. They had their time and digital sound has obviously pushed this medium in to the dark distant past. The units are becoming life extinct and it’s like performing knee surgery on an elderly individual, you are improving their quality of life for the moment until the ravages of old age take over. Bit of a crude analogy I know, what I’m saying is steer clear of these as they are going to be trouble, people seem to think they are worth a fortune and are charging ridiculously high prices for something that just about works.

It’s been fun though and I have learned a lot from it so it can’t all be bad.

Good people, stay safe. Thanks for passing by.

Werra 1

A piece of art-deco / Boho styling from 1966

These cameras were produced from the mid 50s until the late 60s. I’ve done some research on this particular one and the lens number and case number tie it to the year 1966.

I tend to buy cameras I like the look of, I just wish that I’d read into them a little deeper to find out the issues. This camera was so good looking when up against the boxy cameras of the 60s, it was a trailblazer in that the winder for the film was incorporated into the lens. A quick flick of the wrist on the inner lens ring and the film was advanced. Impressive….when it worked and didn’t jam!

You can find out more about this camera by visiting Camera Wiki.org by clicking HERE

This unit is in great cosmetic condition apart from a little age related tarnishing. It has some rattles, the lens needs cleaning and the view finder needs attention. The lens rings are stiff so a little lubrication may be required.

When cleaned I will run a film through it to give a test, I may even reskin the camera to really bring some attention to it.

Please keep an eye out for updates as I will be commencing work on this really smart little antique very soon. It’ll give me a break from working on pesky Sony Discman players 🤦‍♂️

Be happy, be wise. Stay safe

Sony Discman D-171

Assessment and fault finding….will it work ?

My latest purchase from EBay has arrived and god knows what is wrong with this one as the listing contained just one word “Untested”.

There is no one else to blame but me so let’s get this package open and have a look…here goes.

This unit is circa 1996, so there is a gap of 3 years between this and the D-121 that i recently attempted repair on that was badly affected by poor components. Hopefully technology has moved on slightly in those three years, and the plague of the past isn’t as prevalent in this unit.

Well, once in your life you buy something that restores your faith in your fellow man, unfortunately EBay isn’t always that place and you have to take your chances when purchasing using that platform. Today is a good day. The package was minimal and I didn’t hold out much hope. The first thing I did was to open the tray, good it’s working👍

Next I held my breath and opened the battery compartment…. Excellent no corrosion 👍

Batteries inserted I chose an old Bryan Adams album, put the volume about mid way and turned it on.

IT WORKED 😳

Ok, if tapped it jumps, so I will give the lens a clean and will lubricate the worm gear and rail and see if that helps, if not I might test the laser output and make a tiny adjustment but I’ll avoid that if I can.

All buttons have been used, wiggled about and are working fine, all menus are displayed and basically it’s all working pretty much as it should be apart from some little adjustments. The shell is un damaged but a little tatty so a good clean up will assist here.

When taken apart the thing that strikes you is the lack of capacitors compared to the last item I worked on that was only 3 years older. I put some fine lubricant on the worm gear and the laser guide rail and also cleaned the laser lens with some Isopropyl (IPA)

I made a slight adjustment on the laser strength by using the Multimeter to get measurements across the laser pot.

The reading was very low, to what it would have been when new so, I made an adjustment to the higher end of the recommended scale but the unit didn’t like it and refused to recognise any Cd, so I’ve reduced it back to what appears to be it’s operating maximum, after 28yrs I guess the laser is approaching the end of it’s useful life.

Testing the laser

The sound quality has really improved, the unit still skips if it is knocked or shaken but as I’m intending to use the unit on a table or other surface I’m not really that concerned. It’s not as if I’m going to go jogging with it, no chance. To be honest I don’t think the anti jog system that was introduced for this purpose really came in until about 2000.

Put back together, I’ve now cleaned and buffed up the exterior, this is a nice little example of one of the lower end Discman units, but I’ve enjoyed working on it and getting to know a little more about how it works and fits together. I can put this one to bed now as a successful restoration, it’s going in my locker at work for listening to my old Cd collection whilst I’m doing the tedious paperwork or a night shift.

Thanks for passing by, I have another Discman post coming soon.

Sony Discman D-121 Pt:2

Assessment and fault finding… will it work?

My recent purchase of a Sony Discman D-121 from EBay has arrived. Just as described it wasn’t really working so I decided to give it a once over to check condition.

Cosmetically it’s in very good condition, open the battery compartment and it’s a different story, definite signs of corrosion and at this point I’m thinking the worst. I put two batteries in to check, the display comes on and shows some strange indication of “HI VOLTS” even though all I have are the two AA batteries in. Strange.

I do manage to play one song but that’s it, any slight move and it skips and hops and shows a raft of other error messages that don’t Instil any confidence into me that this is going to have a good outcome. Then the CD drive motor breathes its last. That’s it….kaput.

So I open up the unit, and put the circuit board under the microscope. The area around the corroded battery terminal has progressed on to the board and a couple of the circuit board tracks have been totally destroyed. A few components look to have issues and have some spurious test results. A check for continuity with the multimeter confirms that one track is dead and another is intermittent at the very least.

I clean the offending section of the circuit board with IPA and this just confirms the issue, but at least it looks cleaner. If this had been the only issue I’d have happily soldered in a couple of thin wires to the undamaged track to ensure a reliable continuity.

A further look around the board, and there’s nothing blatantly obvious, but seeing this unit was produced in 1993 it’s now in its 31st year of use I also suspect the capacitors (of which there are many) may well be of that era of suspect capacitors I discussed on a previous post. Read here: Capacitor plague

The main drive motor is known to fail after time and a sure sign is if the CD jumps when moved off the horizontal, apparently this is due to bearings becoming misshapen due to use.

This unit therefore is beyond economical repair for me, and I’m not going to progress it any further. The good news is that I can use the unit for spares and as a number of these older units have interchangeable parts, I’m hopeful that as I have a few more units turning up later this week they may have a willing donor.

So the recycling goes on, and that’s always a good thing.

Happy day to you all.

Thoughts 11/3/24

Which animal would you compare yourself to and why?

I guess it would be the Hedgehog.

People always poking at me and seeing my prickly exterior, people always trying to express their love and feelings for me but I’m trying to avoid feelings and emotions at any cost.

In the words of the children’s song:

I’m very Prickly, not that tall

When I feel frightened away I crawl,

And curl up into a ball
Children’s song about Hedgehogs

Yep that’s me, always been a bit of an introvert and a loner. Don’t like crowds….. how have I managed to get this far?

Take care. Love to all x

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Assessment and fault finding….will it work ?

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A piece of art-deco / Boho styling from 1966

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Assessment and fault finding….will it work ?

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Assessment and fault finding… will it work?

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