Radio Comms. In Action

I showed a few Morse Keys on my old web site, I am not an avid collector, nor am I a Morse mode addict. However I am so glad that to obtain my Licence I had to learn the code, I would not want to be without the skill.

Recently IZ0GNY contacted me re the Bathtub Key.

Right Click on pictures and select View Image for full size.

This key was used aboard the Lancaster Bomber and had a degree of sealing against the ingress of water. My friend and fellow Ham G3JJW knows of a good reason for this, he was a Rear Gunner on a Lancaster that ditched into the North Sea. The technique for ditching and being able to escape the Aircraft which was now in danger of becoming a Submarine was for the Pilot to hit the sea hard with the rear end, thus snapping the tail end off. His ditching went to plan and he was out of Lancaster and into a Dinghy with the rest of the crew. Orange dye was used to stain the search area for rescue crews, John G3JJW thereby joined the Goldfish Club, the exclusive group of Airmen pulled from the sea looking like a Goldfish.
Whether the waterproofing of the Bathtub Key allowed any last minute position information to be sent on this occasion I don't know.

I purchased my Bathtub Key when I was 16 Years old from a store which sold 'Army Surplus' it was new in a cardboard box and wrapped in many layers of waxed paper, straight from the Quartermasters stores. I still recall the smell as the wrapping was removed, wax and Bakelite. A rubber diaphragm between the Key Knob shaft and the Body soon perished and crumbled I completely removed this and the ring that secured it.

The top section hinges open after unclipping the Phosphor Bronze catch.

In contrast to the Bathtub Key is my Home Built Squeeze Key.

I sourced most of the material for this key which is based on a design in the American 73 magazine many years ago. The details were provided for it to be build of Perspex (Plexiglass). By this time my son was perhaps a little more than 16 years old and an apprentice Pattern Maker. I persuaded him and he persuaded his employer that this engineering task with so many varied disciplines was an ideal project for spare moments at work.
It took him some time but the results are superb. The rectangular Steel base does not rust due to an etching technique used. The Phosphor Bronze parts I purchased as scrap are similarly treated.

In the above picture I see I have knocked the left hand segment out of its pivots whilst moving it for the photograph. Those movable segments pivot on small Ball Bearings which are force fitted into holes in the Phosphor Bronze these locate into cups in the end of short Steel Pillars, four in all, the left and right top pair can be seen in the picture.

The fixed contact adjustable supports stand on a rod of Ebony timber. The contacts are Copper treated as the other metal parts I have never had to clean them.

The Paddles are solid Rosewood. To show his art (if you ever turn the key over) my son produced the base plate cover of Quartered solid Rosewood. The key is a piece of workmanship of which he should be proud.

It is great to see new licensees building QRP rigs and showing an interest in more than gathering on the Local Repeater swearing and behaving like louts. I have felt for some years now that I can no longer contribute to the local repeater group who provide facilities which bring Amateur Radio into disrepute.

K1JT's WSPR Weak Signal Propagation Reporter software has enthused many operators both old and new. Several times I have noted that there is misunderstanding from many stations about the software and power level setting. More than once the statement has been made that WSPR is so clever in that you can click a box on the GUI and so set your power output down to mWatts.
Let us get that straight you can't.

This spurs me on to write a post in simple language for beginners, at least then I know it is available somewhere on the web.

Given the question 'How does the WSPR software reduce the power of my rig'.

Well it is like advertising if you can't work out how it does it, most likely it doesn't.
How could a computer program alter your radio output unless you have a full CAT control system? Those boxes on the program are Data Input boxes where you tell WSPR what information to send, like you callsign locator and power.

So let us take a look at the output of your FT-450 etc. on USB 'cranked down to 5 Watts'.

Have you noticed that with the Microphone plugged in if you say nothing into the microphone there is no output, if talk quietly the output is low, if you shout it is 5 Watts. Now there is a clue for adjusting the power output. This is due to the audio producing a variable amplitude (yes AM) drive level which on SSB results in more power out given more audio input

When you run WSPR you are putting 4 audio tones one at a time into you FT-450 etc. from the computer, the audio amplitude level of these tones will control the RF output level of your radio. Just like shouting into the Microphone will over drive and distort your signal, the computer output level can and most likely WILL overdrive the rig.

Note. Windows will change these levels when you run other programs, when you return to WSPR or other Digi Modes you need to set up the correct levels again.

Just like not speaking into the Microphone, turning the computer audio levels to zero will produce NO output from the TX. The correct levels will undoubtedly be very low, both WAVE and OUTPUT/SPEAKER level.

Each time you run WSPR or any Digi Mode set the Windows Audio Volume Controls WAVE and OUTPUT to zero and set up the drive correctly or at least check that they are right.
For Whisper level settings set WSPR to TX, measure the output power of the rig at the antenna socket into a 50 Ohm Load. Advance the Windows Audio WAVE control by one division only, then advance OUTPUT by the smallest amount possible, you should see a measurable amount of RF power out. Set your required level by increasing both WAVE and OUTPUT a little at a time to say, 40mW.
So often I have reported over driving to be told 'well I have the Windows Audio controls set about half way'. No actual adjustment. It is so frustrating to hear an ex CB guru instructing a newbie 'just set the controls about half way'.

Never increase the drive level to produce ALC action.If you are setting for a higher power level the correct method is, adjust for ALC indication then back off well below the point where ALC action starts. ALC is distortion like it or not.

Now you can enter your power level value into the WSPR Set Up drop down box and the Data you send will be valid.
I have no doubts that the majority of Hams on WSPR do not measure their output accurately consequently all Data on WSPR.net is invalid in my view.

Personally I have no trouble setting 10mW levels on any of my HF 100 Watt rigs although it does need careful setting.

Finally note that 'cranking down' (or up) the indicated front panel power level on the rig does not change the power you have set by the previous careful adjustment. Go on try it.

"Like trying to tune a Piano with a Feather" that was my description of getting a home brew MEPT tuned in the 100Hz segment of the QRP-QRSS sections of the bands.

When Bill of Soldersmoke fame built his MEPT the only RX he had was a very inaccurate solid state rig that drifted. These are some sugestions I made to help him find his TX frequency. The number of new stations coming onto QRSS and the same problem being encoutered prompts me to write this. In addition my memory does not get better, I use my blogs to record things so that if I go away for a few months and forget something I have a reference.

Like most things a good understanding of the Receive side is essential before venturing a signal onto the air. If you can receive other MEPT's and know their frequencies then you are 99% there.

First the RX needs to be warmed up for quite some time to make sure it has settled.

Here is my Kenwood TS870, a Transceiver I consider to be very accurate and very stable after 5 minutes from switch on the display should read above 070, it will never quite get there it is a few Hertz low but it can be seen to be heading up that way.

Here is my 'G' MEPT signal at this time received by the Italy I2NDT Grabber I have just adjusted my TX frequency to 10.140073MHz plus or minus a bit.

So how do we get Spectran or Argo and our RX to display MEPT's.
First we need to get the received signals in the audio passband of the RX, for convenience 1KHz is a good frequency to choose, it is near the middle of the passband and a round number. No matter what band we are receiving on always use USB (Upper Side Band) and the standard 2.4KHz bandwidth. To produce a 1Khz audible beat note of a particular radio frequency we need to tune 1KHz below its frequency. Hence to receive 10.14000 MHz we need to set our RX dial to 10.13900 MHz.

Next we need to set up Spectran to match.
From the Menu select Mode - Preset QRSS3. The display will now scroll Horizontally.
At the bottom select Show Controls - in the Freq Offset box enter -1000 (minus 1000) as shown.

Now point your mouse to the grey bar between the top and bottom spectrun displays. In the top display is a vertical red line it is reading -150 or more at the red line, Left click the mouse and drag the scale to the left through Zero to place 100(+100) at the red line.
The Right hand vertical grey scale now reads 10 - 20 - 30 up to 100 if it was not hiding at the top. This scale now shows the 100Hz of the 10.140000 to 10.140100 QRSS Band.

When you close Spectran these settings will be saved so you only need to set up once.

If you are new to Spectran do some thinking and tune to the frequency you need to to display WWV on what ever frequency you can hear it on, check the accuracy of your RX dial.

If you are seeing MEPT's you can put your newly built TX into a Dummy Load and adjust its trimmer to sit your signal where you want in the QRSS band
But beware there will be more than one of you, even with a few mWatts into a screened dummy load you will find it hard to get rid of your signal.

Here I have re-tuned my RX 70Hz higher than 10.13900MHz the signal is some 30dB down but strong, comparison with the Left Hand side of the trace makes it obvious which is the fundamental.

This is where the Feather comment comes in, a tiny adjustment of the trimmer can shift your signal way out of the 100Hz window, you are using a Dummy Load so tweek and twiddle to get used to it, like all things after a time minute adjustments become easy.

When you are fully confident in your skills, settings and accuracy you can put your MEPT on the air. If you are lucky like me, (I2NDT Grabber is almost a certainty during daylight hours) your signal will pop up right on your determined frequency on a Grabber. Alterantively you can get a friend to listen / look for you but beware many Hams do not know within 200 to 300 Hz where they are on the band despite what their dial reads.

First of all I must recommend a site for all Sammy Lovers, I discovered it a bit late, I had made my decisions on what was the best Netbook around and solved the problems, well nearly all of them, no one seems to have all the answers yet.

http://www.sammynetbook.com/news.php has a lot of members all of them just luuuve their Sammy and there is a lot of expertise on hand.

A user on Sammynetbook.com mentioned that his wife got shocks from her Sammy, a case of His and Hers Sammy's in that household, lucky people. He got no such thrills from either His or Hers.

I am still waiting with interest on some tests suggested, swapping Power Bricks etc. However I think that there is nothing to worry about, Induced Voltages are a fact of life. Other users have confirmed slight tickles from their Sammy too.

I measured the DC Output of my Sammy Power Brick with a DVM - 19.1 Volts. Then I looked at the AC Voltage from the Negative - Sleeve of the Power Brick to Earth (real Earth) - 69.2 Volts RMS.
I was not surprised by this figure all sorts of mains powered devices can give you a tickle to Earth due to Induced Potentials.

In order to confirm that there was nothing unusual in the Sammy results I checked the Wall Wart Charger for my Sat Nav. - 69 Volts AC from Sleeve - Negative to Earth.

I wondered what the AC waveform looked like so I hooked up the old Telequipment D54 scope and took a look.

First the ripple with the PSU plugged in but switched off as the reference.

Next I looked at a Wall Wart which uses conventional PSU techniques (transformer). There was around 20 Volts Peak to Peak of 50Hz ripple to Earth.

Next the Sat Nav Switched Mode Wall Wart. A rather spiky chopped waveform but surprisingly 50Hz, I expected to see more of the evidence of the switching frequency. The Amplitude is around 130 Volts Peak to Peak.

Finally the Sammy Power Brick an almost identical waveform and Amplitude.

Being an Induced Potential it is not going to be of any danger to users. I looked at the current capability to Earth, DVM 20mA AC range, as expected a flick of digit upon connection sometimes but no measurable Current at all, I assume a low impedance load will pull the voltage to zero.

Such Potentials could damage sensitive electronics so there is as always a lot to be said for proper bonding and / or isolation of all interconnected equipment.

One thing is certain the DC from the Sammy Power Brick is clean of noise, I understand that some Laptop Supplies kick out so much interference that they can wipe out broadband.
Also I have it on good authority one of the Asus EeePC supplies created so much noise that it spoiled communications applications.
A further great advantage of the Sammy is that considerable periods of operation can be had from the battery supply thus eliminating any chance of mains borne noise.

Incidentally I notice that back in December 2008 there were Amateurs who were Sammy lovers, users on the Ham Radio Deluxe site, well I had fun pioneering all alone. Why do we find out these things too late despite a thorough research on the web.

Since the purchase of my Sammy (Samsung NC10) Netbook Computer the Green Power concept for my portable operation will be more fulfilled. In the past the computer use has been limited due to the current required.
At home my Solar Power is merely a token addition to the power used by the radios and computers. When we are 'out and about' we are solely dependent upon Wind and Solar power. The consumption at 12 Volts of the Sammy is around 1 Amp. this brings it into the use as much as you want to category.

The 12 Volts is stored in two 85 Amp Hour Leisure Batteries. The Solar Panel is a 50 Watt unit. Be careful when thinking in terms of rated Wattage and expected Current with Solar Panels. Current is found by dividing the Wattage by the Voltage, do not make the mistake of thinking this will be 50/12 = 4.166 Amps. Manufacturers rate the panel at its maximum Voltage which is maybe 18 Volts, therefore 50/18 = 2.77 Amps is more of a realistic figure. What is more this is the maximum output in full sun, in the winter 0.4 Amps is often encountered at mid day.

My wind power is derived from an Aerogen 4. Again giving direct figures for current output is not straight forward as the output is dependent on wind speed. Suffice to say it can produce 4 Amps in a stiff breeze and 19 Amps continuously in a good 60 knot blow.

The 12 Volts nominal Voltage from the storage batteries is no good for feeding the Sammy direct. I chose the Nikkai A33HU Car Laptop Power Unit (Maplin) to provide the 19 Volts at 2.1 Amps Max. needed. This unit rated at 150 Watts does not even get warm when providing such meagre needs.

One of the most important things a computer has to do for me is to enable connection to a Radio Transceiver and run Radio Communication software. Any computer not capable of this to me is a dead parrot. Yes they can connect to the internet and do all sorts of lovely things but that is via wires and telephone exchanges etc and at a fee.
Connected to a Transceiver it comes to life and whether I am typing on the keyboard or sending coded data or Still TV Pictures the world is at my fingertips.

We can send our position from GPS continually whilst driving (APRS) allowing other users to track us via radio. Using the right software we can send (rather high power) signals to be bounced off the moon around the world. Personally I prefer very low power (QRP) operation. At very reasonable power levels (15 Watts) I like to use the 50 MHz VHF Band (around the frequency of the old Band 1, BBC1 TV) and reflect signals from Meteors.
Some Meteor showers are large, come at pre defined times and are named, these produce the 'falling stars' often seen on dark Autumn nights. What is less known is that there are Meteors hitting the Earth's atmosphere all the time. Some are no more than the size of grains of sand or dust, when they burn up in the atmosphere they produce an ionized trail which is capable of reflecting radio signals.
Having said that I put the Sammy on whilst writing this blog and was getting a little worried that I had had no results. Early afternoon is not a good time and the predictions for meteors are low, however I was not disappointed.

At 14.53 GMT there were several reflections, one burst of signal can be seen in the capture from the Sammy desktop above and a perfect de-code of the signal data. The other station is in the UK out of direct communication range on VHF for me. The same Meteor could have reflected signals from Scandinavia, Eastern Europe, Italy, Spain or Africa.
In the software used there is quite a bit of processing going on, Fast Fourier Transforms and Fortran routines, the sound 'card' In and Out needs to be of pretty good linearity and low noise for this sort of work too.
Can the Sammy do it? yes it can.

I have spent a little more time looking at Linux on the Sammy. Ubuntu 8.10 boots up fine, I did a quick test initially, just to prove to myself that it would work.
After a little research it seems that Ubuntu 8.10 does not support the Atheros WiFi 'out of the box'. No problem the driver is available and easy to install, however it seems that every time Ubuntu updates it undoes the work you have done and you have to re-do from start. Still not too bad but hey, it seems Fedora 10 works out of the box according to reports.
It is not just the Wifi support that is better other support is covered too. So yep of course I have tried it.

This blog is posted using Fedora 10 the capture is of the Sammy desktop. Good another step completed, we are ready for super safe browsing on open networks.

Following the comments from 'balmaha' on my previous post, (he won't last long now, another Sammy sold) I have today gone the full mile and purchased the Maplin Car Laptop Power Unit I mentioned.
A very good buy at the current offer price, rated at 150 Watts it slumbers along on the Sammy. It has been on for 3 hours and still feels cool.

Measuring current when the connection is a Cigar Lighter Socket is not easy so I am using my DC PSU meter as the not highly accurate instrument. When charging the Netbook Battery the current is slightly less than 2 Amps by the look of it and just over 1 amp once the cells are charged.
I have not gone for critical power saving settings, back lighting is at mains power level, performance full, USB GPS powered on, Wireless Internet on and connected and Bluetooth on too.

This gives me a portable radio set up using the FT-897 with a total current consumption of around 5 Amps on TX. Mind you on WSPR for an output of 1 Watt, 69 Watts consumption is still pretty disgusting.

Incidentally internal Battery powered I viewed a few videos on Youtube, tried out the GPS on a stroll up the road, slung the Sammy on chair still switched on while I ate lunch picked it up an hour later and the battery indicator said 6 1/2 hours use left. One day I will have time to run it flat.

Personally it gets my back up when people avidly support junk just because they made the mistake of purchasing it, for instance the Icom IC706.
So do not take my word for it take a look at the views of 799 other purchasers here PURCHASER REVIEWS.

The specs seemed to indicate that it would do it. I 'spose I was a little rash to take the plunge and buy a Sammy to try. Well it does. What? Perform just like any other 1.6GHz Windows XP Machine with 1GHz of RAM and a 160GB hard Drive. The Intel Atom Processor means it is small and low in power consumption, high in performance.

Of course being a Netbook what it does not have is an Optical Drive, there just isn't room, the thing is only twice the area of a CD anyway. This means any disk bound software has to be installed from a USB CD Drive or in my case from a Networked Drive.

Installing MS Autoroute from a Networked Drive is not straightforward, it comes up with a message immediately telling you that it can be done but not the way you are trying it. The way that is outlined didn't work for me. Solution is to put the contents of both CD's into one shared folder on the Master Machine and map that folder as a drive on the Slave (Samsung).

I have come across a couple of small problems. My Bluetooth GPS plays up, it has never been easy to pair and is old and slow so a USB GPS Module will be the best solution there. The Samsung Screen Saver and the Samsung Software Updater do not allow for a non administrative account user. Log in using a restricted user account and a. the Updater complains and b. the Screen Saver crashes. In time they will no doubt both have to go, word has it that the Software Updater is not that clever anyway.

For assured safety I am using my fully isolated home brew interface between Netbook and Radios. A poor quality photo, sorry, it has Opto Isolated USB Rig Control and Line Isolation Ttransformers for Audio In and Out.

The Ham Radio Aplications I have tried out up to now are are covered in this video. The 'Sammy' is a Netbook that thinks its a Notebook and does what a Laptop can do.

I had to do it, my existing Laptop which I use for Portable is a Dell Latitude. Purchased second hand it has done remarkably well, it runs Windows 95, the Display is 16 Colours so photos and SSTV look weired.
That old girl boots up and closes down quicker than my 2GHz Dual Core machine running XP, its OK for Packet, SSTV, PSK31, Hellschriber and would you believe it has been my standard machine for WSJT JT6m Meteor Scatter, running WSJT the clock loses as the machine devotes its time to de-coding and I manually correct it continually during a session.
Why do I put up with it? well it's connected to the 6m rig you see.

The battery is wrecked which was a problem for Portable operation untill
I tried one last trick, I chopped the power lead fitted a couple of 4mm plugs and connected it directly to 12 Volts. It works a treat, now there is no question of battery life, well not really I have 160AH of battery storage when the sun is not shining or the wind blowing, if the Green charging is taking place its a win win situation.

What that old girl won't do is Wireless Internet and Mapping and Navigation and some of the more demanding Radio Communications tasks. Come on now you tight old git, its time you got the Plastic out ready for the next /P season.

As I have said previously, being mean I want the replacement to do shack jobs as well as /P and Internet Cafe, that is why I have researched for several months. Finally the right machine and some Sale discount have come together.

I had just a little aprehension re the loading and running of Ham Software and Linux so I have done the first checks, I have run Ubuntu 8.10 and Fldigi booted from USB Stick. Also WSPR 1.1 on Windows. No time yet to connect a rig and my Home Brew Opto Isolated USB interface but I have no concerns about it working, it was tried and tested on my Zoostorm Laptop and the software runs and Ouptuts audio fine.

When surveying the available Netbooks it is easy to get quite addicted to YouTube Unboxing Videos judging by the hits they get they do provide a valuable service. It takes a little self control to share the parcel opening process. Here is my Blue Version of the Unboxing Video. Ha! pun intended.

Blog written and posted on Samsung NC10. The keyboard is comfortably large for phat phingers, battery life 7.5 Hours, coo I haven't tested that out yet.

I have commented on my companion blog about the EeePC. Personally I think that by using a cut down obscure Linux O/S Asus did Linux no favours. Only recently did I read a review which said 'If you are a child then buy an Asus EeePC'. That could be about right, unfortunately Linux is thus presented as a 'can't do O/S rather than a 'can do'.

A whole generation will know 'because they had one' that Linux is OK for Browsing, E-mail and a few Games but that's it.

Since the first Asus Netbooks there have been many more makes and models of Netbook, some have 120GB Hard drives instead of the SSD Cards which have a finite life of read/write cycles, this cannot be good for 24/7 use such as WSPR. I have considered purchasing one for Ham Radio use. The Linux versions installed still do not come up to scratch, a pity because the machines are capable of running a full distro.

Today I downloaded and installed Linpus Linux as used on the Acer Netbook range. Whilst it is fine for plain ordinary Netbook use it is far short of a Linux distro suitable for Ham Radio.

This leaves two options, buy the cheaper Linux version with a real Hard Drive and instantly replace the O/S, not something I would really want to do.

Alternatively purchase the Windows version and run a USB booted Linux on that. Problem is the cost is coming close to that of a real laptop with a CD/DVD drive and all the advantages that come with a higher specification machine. Shame, I would like to play with one but I still can't talk myself into it. What will the recession do to prices I wonder. I have noticed that the only price reductions in the so called 'Sales' are the reduced VAT. Otherwise the January sale price is the same as last summer. I wonder do we need to buy soon before they become unaffordable?

That is ignoring the PC World advertised prices, yes they have none for online purchase, none at any store for collection. Just like the advertised £2.49 1GB Memory Stick and the £6.95 80GB Hard Drive they don't have any. Who do they think they are kidding.

WSPR is a mode which was purposely designed for QRP Propagation Study. The whole point is to radiate a known level constantly repeated signal and analyse the resultant Spots of that signal by disparate stations around the globe.

"But hang on there I see that T1WIT is getting Spots from America I had better turn up the Power until I do" is the logic often used. No propagation to W1LOUD using 100mW means that conditions are not favourable at that time, a valid piece of Data for Propagation Study. Turning up the Power until you get results invalidates all Data, as does not knowing what your Output Power really is.

Personally I can set a stable measured 10mW Output from my 100W Commercial rigs if I need to. I would much rather build a QRP Radio that consumes a few Milliamps for a few Milliwatts Out.
Ignoring the Computer consumption, on WSPR we have many stations with an HF rig consuming 60 to 100 Watts to produce 100mW of RF. What makes me smile is the fact that a Commercial Step Attenuator is then added to the set up to dissipate the power just generated.

The Elecraft AT1 or some other commercial Attenuator is listed in the equipment used as a modern 'badge of honour'.

Well at least the AT1 is available as a kit so you can have had a hand in this Modern Farce.

Why Cinderella?
In the week prior to the Easter weekend, having completed my Top Band MEPT I was looking at using a similar design for a 40m unit with my 7.00MHz Crystal. Then I received an Invitation to join DL6NL and G6AVK on 14Mhz for a Holiday Weekend activation.

I searched through my Crystals, all I could find was a 5th overtone one which on its Fundamental was out of the top end of the band. With just 3 days to go there was no time to order an Xtal so I replied to Peter DL6NL "thanks for the invitation to the Party but I have nothing to wear."

Going back to my 40m construction I wondered if I could select the Second harmonic from a Class C stage and get 14 MHz that way. I succeeded in getting a low level signal which was rather scruffy looking on the scope. I considered a Diode Ring Doubler circuit, fine if I was after a low level signal to amplify using several stages, not really simple MEPT stuff.

I moved to a digital Oscillator. Dividing digital signals is easy, doubling is not normally done, there is little information available on any techniques. If we were to put the 7.00MHz signal through enough digital gates we would get a delay of the signal. Apply the delayed signal and direct signal to a pair of XOR Gates and if the delay is correct we will get 2 pulses in one time period.
Alternatively a phase delay can be achieved with an R/C network both methods worked and on the day of the 'Ball' I was able to announce that 'Cinderella has sewn a new Gown and would be coming to the Party'.

I used the Gate Delay method in a bread board 'lash up' with a 2n222 Driver and BFY50 PA.

The 50mW TX fared well, conditions were not good but we were all copied (Cinderella and the Two Ugly Sisters) in Nova Scotia and Northern Utah.

I am below G6AVK and DL6NL in this capture into Utah a very thin signal barely visible but I was running 3dB less ERP and of course the antennas and paths are different.

Peter DL6NL announced the switch off time for his activity Noon on Tuesday. At the stroke of Noon my Cinderella TX disintegrated into a pile of components and a single Crystal (slipper).

I embarked on the permanent version, characteristics were different without the long leads I found a combination of Capacitive Phase shift and Gate delay with critical adjustment of the Capacitor gave precise linear results.

I used to despise Veroboard. Costly,Warping Paxolin and lots of stray capacitance between the rows, however it is quick and easy for IC projects and used wisely the capacitance can effects can be minimised.

The signal generation uses two 74HC86 IC's Selection of 7.00MHz or 14.00MHz is by the positioning of a single link.

Ideally suited as a PA is the 74LS240, having 2 separately enabled banks of Inverters. Band Selection is by a movable link for Enable and another for the Drive to either section. this means the BPF for each band can be permanently connected to its PA.

Separate plug in Band pass filters are used, this including a socket for the crystal means the MEPT is in fact universal and Multi Band.

Link swapping is no problem as the whole MEPT needs re setting when band changing, the FSK shift is doubled when the signal is doubled.

The MEPT is on its test run now using my spare PIC Keyer piggy backed on.

During the tests I tried a new method of Identification conceived to try and overcome the problem of missed identification due to missing parts of Morse Code symbols.

I now call this 5/5 It is 5WPM FSK Morse with a 5Hz shift. If I send my Call Twice and the two letters of my Major Locator Square this forms a Morse Code G in QRSS5 with a filled waveform.

Here it is into Nova Scotia, doing a fine job.

Manned Experimental Propagation Transmitter for Manned Experimental Propagation Tests.

A new MEPT band, for me 160 meters. I could build the same tried and tested design for all bands but the fun is in the experimenting. This Transmitter uses only 2 Transistors. NPN Crystal Oscillator DC coupled to a PNP Output Amplifier an ideal use for the old BFX29 transistors in the junk box.

Based on an old design from G3MY called the Pippin it is capable of more power than needed for a QRP Propagation Beacon. I used a DIP Switch to select collector load resistors. power levels from 5mW to 400mW are possible. The Crystal available needed pulling low, determined to use the bits from an Energy Saving Lamp I wound the inductor on the toroid former which saw previous life as the Lighting Pulse Transformer. The output capacitor and some decoupling came from the same source.

The other variation that can be made is in the construction method, I have used the Pad on Earth Plane method for VHF PA construction, it lends itself well to this project at the other end of the frequency range. I piggy backed my old test PIC Keyer to FSK via a Black LED once again used as a Varicap Diode.

Once complete I put it on test running 100mW to my 40m 1/2 wave Doublet, my e-mail being down I could not ask for reports, it would need to be spotted by a keen Top Band monitoring station, this was a week day and the week ends are more popular for 160m experiments.

When I managed to get some incoming e-mail a couple of days later I was pleased to see.

[Knightsqrss] who is on 160m? G6AVK

Later he searched the Captures for the most readable segment and deduced the call and QRA Locator. Well done and thanks Colin.

To start to understand the mechanism involved in the locking of two CMOS oscillators on the same chip we need to know a little about what goes on inside the DIL Packaged device.

Thanks to Peter G8EUX I now have an insight.

The 5 Ohm resistors and the 5nH choke which also has a resistance of around 5 Ohms are all inside the chip.