TF3CY

6m EME – QRV and QRO ?

tf3cy — Tue, 13 Jul 2010 16:59:03 +0000

I have gotten few emails asking for sked’s on 6m eme.

As my current working conditions are uhm… none – I can’t have a fixed EmE installation at my QTH. So I have this portable setup that I plan to use when I have good conditions.

Good conditions mean of course low degradation – but also as I live on the south-west coast of Iceland, I would like to be able to see the open horizon. So any azimuth to the south-to west would be great – my grid square is HP94 so that will give you some idea how to work me. I will be trying to find a location I can leave the antenna over night, so I will perhaps 3 days I can work the moon.

I will be QRO soon – I’m still waiting for the experimental licence as our normal general class only allows 100W RF. I have asked the PTT to be able to transmit 1Kw RF, hopefully that will be granted. I have a 1200W solid state amplifier I’we nearly built and will be tested in the next days.

so please email me if you want to arrange a sked email is benedikt@ccpgames.com

I’m going to try to work as many good “windows” as possible this summer. Next window I’m looking at is around 12 August – then the moon will be in a good position for me to work the low elevation with good degradation.

Two 6m EmE contacts W7GJ and W1JJ

tf3cy — Tue, 13 Jul 2010 01:17:40 +0000

Today was just amazing. Just few weeks ago I got this crazy notion in my head to try EmE, and that on 6m, actually it was Lance W7GJ that spotted me on a cluster and looked at my locator/location and saw a opportunity. When I got the email from him something just clicked, I had always wanted to try EmE, but always thought it was impossible..

Two contacts where made, W7GJ and W1JJ ! more would have been possible if the problems with the PC-rig had not taken so much time.

So here is the story

I decided to build a 10el yagi, have it portable as my current QTH does not allow large 15m boom yagis, the yagi copied from Pop YU7EF excellent designs (http://www.yu7ef.com/). My brother TF3SG has a portable full size 80m vertical and it’s build quite robust – so I decided to borrow it and use the lower half as a mast for my new yagi. This is just something every ham has to have.. a portable mast on a trailer.

Here are some pictures:

[View with PicLens]

This would never have been possible if it had not been for all the hard work my brother TF3SG put in, both he had the mast and helped me throughout this endeavour. He even went home and got his beloved FT-2000 when I had all kinds of problems with my small TS570. I ended up taping the mice of the FT2000 to a USB headset to get the audio from the PC to the transceiver. Then of course my father TF3T (formerly TF3SG), watching him throughout the years trying to build impossible projects and often succeeding lead me to try this.

We had all kinds of problems, mostly rig to PC related that should have been fixed before the try, but what amazed me was the performance of the beam, first try SWR 1.1.

I will try to get QRV as soon as possible, but I’m supposed to return to the summer house my wife and kids are staying at – and stop this nonsense

But, this is really what I think amateur radio is all about – experiment – build stuff, break stuff – and use the moon as a reflector!

The location we chose is very popular sight seeing location – so we had alot of visitors asking “What are you doing”, I just said “I’m sending a radio signal to the moon and using it to bounce back so I can communicate with someone on the other side of the planet”, and usually they replied “… haha no, really what are you doing”.

6m EmE – almost

tf3cy — Sun, 20 Jun 2010 09:42:41 +0000

As TF1SIX was spotted on 6m yesterday, weather good, moon in good position, I decided to get my new yagi up to test. I had tons of problems as I did not find the top bracket on the rotor, so I had to make a custom bracket. The aluminium mast material available was only 70-60mm, so it was not the sturdiest masts around.

[View with PicLens]

The picture shows the takeoff to around 200° where the moon was yesterday. Hope the president of Iceland has upgraded his TV equipment and is not using the old 50Mhz transmitter still around. The ground path to the moon goes over the narrow peninsula called Álftanes, back over the sea, then has to cross 20-30km of the Reykjanes. So the location is far from optimal. I plan to use my brothers portable mast to get closer to the open sea.

3rd picture is from Google Earth, Shows the path the signal takes.

Last evenings tests far exceeded my wildest expectations, I was able to copy Lance W7GJ in DN27

232800 1 -23 3.7 75 3 * TF3CY W7GJ DN27 1 10

So now I wait for the next window – and prepare.

New 6m yagi

tf3cy — Fri, 18 Jun 2010 22:02:46 +0000

After all the Es fun on 6m and encouragement from some of the EmE guys I decided to build a bigger yagi, I was originally going to build a 10 element but I was very sceptical about building a yagi with a 15m boom. So I opted for optimized 6 el yagi on a 7m boom. This yagi is quite cool, designed by Pop YU7EF, http://www.yu7ef.com/ef0606.htm

I used 40mm and 35mm square boom material and 10mm elements. It’s quite rugged but it will not survive the winter here in Iceland. So it can be disassembled into max 3m parts.

[View with PicLens]

Feed point impedance of this yagi is 50 ohm so I only have to use a simple balun to connect the coax.

I was quite supprised that it just matched perfectly and has SWR 1.1 at 50.100

… uhm..that’s what the graph in EzNec showed..so I was supprised I could build the thing so near specification!

So, now I just wait for the moon OR Es top open up

Very fun 6m run tonight

tf3cy — Sat, 12 Jun 2010 01:19:15 +0000

After putting up the yagi and not hearing a single beacon for few days I was becoming desperate, so I finished my HRD + Ipsound setup and rigged the TS-570 for remote control. Now I sit @ work with the 6m band humming in my ear.

I can’t use the remote control to transmit, I think all my co-workers would send me to some nut house if I would start DX’ing in the middle of the office..

So around 16:00 GMT I heard a weak beacon, so I hurried home and started skimming the frequency, nothing.. just went. So around 20:39 TF1SIX was spotted and I started calling CQ … without hearing any other beacons. I got a solid response from MM5AJW. So as the night progressed I ended up with around 50 contacts, around 15 to the east coast of USA.

Now I got a very interesting mail I have to read, urging me to try EME on 6m !!

6m yagi – working

tf3cy — Mon, 07 Jun 2010 09:40:44 +0000

The 6M yagi is working, testing with my father (TF3T) is scheduled to try to see if it’s really working, measure F/B and gain.

This is a picture of the driven element, I scratched my head for a long time, getting very strange readings trying to match and tune the element. There was a very apparent design flaw that I did not see. Can you spot it? ;P

It’s now fixed and SWR 1.2 on 50.1

6meters – my new favorite ;)

tf3cy — Sat, 05 Jun 2010 18:56:29 +0000

My brother, Gudmi TF3SG, sent a email to the local amateur group that he heard a beacon on the 6m band. I have not been very interested in this band before, but decided to jump to 6m on the TS-570. My antenna is a short G5RV dipole strung from a tree to a scaffolding. I started scanning the band and heard a faint beacon on 50.093, I tuned slowly up band and fond a very strong signal, S9+. My first thought was that this had to be a local station close by, but it was David, MM5DWW. I decided just for fun to try the auto tuner in the Kenwood, thinking even if I could get around 5W into the antenna I should make it work. To my surprise, the SWR was low, 1,5 so I just went for full power and responded to the CQ. I took 3 QSO’s that night (1 june at 23:44 GMT), then my wife yelled as she was trying to get to sleep.

Now I must be ready for any opening and started building a yagi for the 6M band.

So here is some pictures of the ruggedly built 6m yagi, I went to google for design ideas and after spending to many hours reading and looking at different designs, I had transferred a yagi I found in the ARRL handbook over to metric measurements, but I decided in the end to use a optimized design from a German webpage – but when put in EzNEC, I could not make it work. Then I found out that the diameter from the ARRL is quite big, 20mm – to 16mm that is a total overkill for a 3m span, but I had to change the scale of the antenna. So – I’m going to test the antenna – works perfectly in EzNEC – but let’s see how it fairs in real world.

[View with PicLens]

I also should state that I have a special connection to the 6M band, my father TF3T – formerly TF3SG was the first amateur in Iceland to get the permit on 6M and make the first contact, I think he was one of the first in EU actually, need to ask him about that. But somehow I have always been uninterested in the 6M band – that changed after my first QSO’s.

- TF3CY

600W – still going on

tf3cy — Mon, 01 Mar 2010 13:22:31 +0000

I had high hopes working on the project over the xmas time, but it turned out to be a very busy time, followed by a hectic work schedule, traveling etc… So after not being able to take part in the CQWW 160m contest due to lack of equipment I started the work again. I just finished making a filter board prototype and finishing the SWR metering bridge. Will post here late on. I’m now in the process of ordering a second EB104 with a splitter/combiner so the end result will be a 1200W linear.

600W – build prep

tf3cy — Thu, 03 Dec 2009 14:19:56 +0000

So, I have now designed the filter board and calculated the values of each of the 6 filters. I have some 1000V silver dipped mica capacitors that I’m going to use, and have been adjusting the toroids to match them 100%. I decided to use 5 element low pass filters in stead of the 7 element commonly used. I saw the design in the Ameritron ALS-600/1300 and according to Elsie filter modelling software they should work fine. PLEASE comment if you have something to say about this decision. I will post the filter calculation later when I finish transferring them from Elsie to some better form.

While @work, I played around making a block diagram of the amplifier + some front panel ideas.

[View with PicLens]

The complexity of the control board startled me, I see that I have to multiplex some of the input/output. The 16f877 has 8 AD inputs, 2x full 8 bit GPIO. I’m compiling a list of all IO and I will probably for simplicity use one of the 8 bit bus for controlling the LCD. I want to keep the serial UART unused for future expansions (remote control), then I have to figure out how to get the band data from the xmit, I have some old QST article showing a PIC based antenna switch so I will probably just use that design. Using a 74hc374 tristate latch to multiplex one of the data buses will probalby be the choice.

I plan to fire up the amplifier next week for testing and start the output module into a dummy load. I will probably use a manual bandswitch to control the filters. I’m NOT going to start operating the amplifier without the control circuits, but I have xmas to look forward to now.. I finally have something to do ;P

So the info I’m now starting to look into is the ALC circuit, and the band data input from the transceiver.

Spreader drilled and tapped

tf3cy — Sat, 21 Nov 2009 20:46:09 +0000

I had some issues drilling the spreader, I thought the drill would go through the copper like butter, that is partially true, but as this is a very thick piece I’m drilling, it grabbed the drill and twisted it. I had two 2.5mm drills twist to bits and I could not get them out of the hole. This actually happened on the first hole I drilled, so I ended up moving the whole PC board 2mm to the side. Now I marked the MRF150′s and I think it’s very important to mark them first, drill and solder afterwards so there will be no forcing of the pcb when they are clamped tight. Unfortunatly I broke on drill in one of the mrf150′s mounting hole, but I could drill the hole and tap it. I hope I did not damage the tapping drill, as a bit of the old drill was wedged in the hole!. secondary plan was to widen this one hole to M4.

Here is a picture, this was surprisingly badly drilled – I blame not having a proper tool to mark with ;P

here is a picture of the “handywork” – put some lines over to see how it really went, it’s still withing tolerance and the mrf’s are clear of the PCB, and no forcing when taped down. I used M3 screws – and for that I think you have some room for “mistakes”