Amateur Radio Homebrew (Shack Culture)

Post by **Stanley** » 19 Jul 2013, 02:43

My new ones have settled down nicely Bodge....
Ian, I'm reading le Carre's 'The Looking Glass War' again and it struck me you'd like the technical bits about the old wartime radio sets they used to use behind enemy lines.... Lots of stuff about changing crystals and coils and tuning aerials....

Post by **PanBiker** » 20 Jul 2013, 15:37

I have gathered more bits for the wire antenna. First is the 300ohm ladder cable that will be used for the radiating lines. The design is basically an end fed wire arrangement but with twin wires out of the transformer. Picture shows the cable and a small box I picked up to house the transformer and connections. You can see the slotted design that gives it the name of ladder line, the spacing of the two conductors and the cut outs in the ribbon are what give the cable it's characteristic impedance of 300 ohms. The slotted nature of the line will also allow me to attach the Paracord support line to the end of the cable without using a separate insulator as termination which would be required in a single wire design.

The next picture shows the Paracord 550 with Digital Camo jacket. Paracord was originally developed in the US during WWII for, as the name would suggest, for the lines on parachutes. The cord consists of 7 internal twisted strands of nylon surrounded by a woven nylon outer jacket. It has a breaking strain of 550 lbs. The original use has now been expanded as the material can be put to a multitude of of uses if stripped down to its individual components. Individual fibres from the core can be used as a fishing line or made into a snare, you can hang things with the bare cord or use it for constructing emergency shelters, there are hundreds of uses that you can put the line to in an emergency situation with a little ingenuity. Woven designs for lanyards, belts, cross webbing and the like can be fashioned using Paracord. As the material is very light it can be woven or knotted into many designs that will use a useful length of the material which could come in quite useful in an emergency situation. A simple woven bangle worn on the wrist can when unravelled have a few meters of Paracord you can use tens of meters if you make it into a belt. As the material is nylon the end of the cord can be sealed by heating so it does not fray.

The other items in the photo are a couple of closed screw eyes which will be used as fixing points for the antenna and two carabina's for attaching the Paracord support lines. If it was a single wire design I would have used a wire "curly whirly" strain relief at each end, the same as BT use to cable the telephone wires from pole to building.

Post by **Stanley** » 21 Jul 2013, 04:22

You remember there was something else yesterday? I remembered what it was, two items: The collage in the TSB and the fact that you've got rid of that annoying headline on the pics and if you click on them you get the full size image.....

melteaser · Post by **melteaser** » 01 Aug 2013, 13:23

Imindoors is currently having fun being 'F/G0 DUI' One connection has apparently told him to be careful not to annoy his XYL whilst he is an F!

It's nice to see him relaxing while we are here.

Panbiker, he has posted more technical stuff about this on his website. There is a link for the above callsign apparently. He is particularly proud of a coil he has made

Post by **Stanley** » 02 Aug 2013, 03:31

Morning Mel, nice to see you popping in.....

melteaser · Post by **melteaser** » 04 Aug 2013, 07:15

Morning Stanley. Just thought I'd send an update seeing as imindoors was doing something a little different and new to him.

Post by **PanBiker** » 04 Aug 2013, 16:00

hi Mel, on holiday at moment, just looking in using Ipad. Free wifi where we are. Good news on the F call. Got my dual band handheld with me but not much activity down here in the back of beyond. Will catch up later.

Post by **Bodger** » 03 Sep 2013, 08:28

PanBiker, this may interest you, 1940 automation on circuit board production
https://www.youtube.com/watch?feature=p ... QHizDkrFqg

Post by **PanBiker** » 03 Sep 2013, 16:20

Thanks for the link, fascinating and not just circuit board but actual passive components produced from the layering techniques of the production process. Only capacitors and inductors but the forerunner of semiconductor integration which came along a little later in 1949, SSI, MSI and LSI followed (Small Scale, Medium Scale and Large Scale integration). Ultimately leading to what we have now with millions of semiconductors and passive components all in one chip. The 1940 processing machine ran totally on motors, electromechanical relays and photoelectric sensors. All about to change as each successive generation allows you to use the enhancements you have just developed to produce larger and more powerful systems. A nice find Bodge.

Post by **PanBiker** » 27 Sep 2013, 12:27

My new bits of wire are now deployed courtesy of a bit of help from my lad Jack on the weekend before we went on holiday. I have let my auto ATU have a go at "learning" the new design on all the bands and can report that it can find a match on all bands that my transceiver can handle except for 160M - "Top Band". No surprises there as it would be a bit of a miracle to get 20M of wire and a toroid transformer to emulate even a half wave resonate length on that band as that alone would need to be over 260ft long!

I can certainly hear a lot more stations on the new set up. As an end fed wire design it may benefit from an earth counterpoise which is not very easy to achieve with a loft based station 20ft or so up from the ground. My station is at the opposite side from my front garden which is now fully populated and in any case is not big enough to accommodate suitable lengths of buried ground radials or an "earth mat" which really lend themselves to manicured grass areas.

I may look at an electronic solution to provide a suitable earth. I may be able to use my "transmatch" featured earlier in the thread with a bit of modification and metering which I could add as a small separate unit. Or I could build a suitable unit from scratch. I don't have a problem with any RF feedback into the station which is a good indication that the design is working as it should. No "hot mikes" or tingles from the equipment when transmitting. So any counterpoise system I can introduce should be an bonus on the signal. It may help to both boost the radiated signal and suppress some of the electrical hash that all antennas pick up from the electrically noisy environment they are surrounded by.

Most folk would be amazed at what the radio spectrum actually sounds like in reality. Domestic equipment such as TV's and radios only work in small portions of the available spectrum and are largely immune from the rubbish but all contribute to it. This background noise can represent a few S points degradation on incoming signals and is totally down to the myriad of lousy electronic designs pushed out as "state of the art" mobiles, computers and electronic gizmo's of all flavours. Bluetooth is a disgrace and works on the very principle of a "dirty signal". Most of the manufacturers of such wizardry would be out of business in a flash if they had to comply with the same non-interference criteria pushed onto radio amateurs as part of their licence conditions.

Time will tell anyway, it's early days for the new design and as Autumn and Winter HF band conditions improve with different propagation effects coming in to play it will take my little auto antenna matching device a while to learn all the new settings. First impressions though look promising. Oh I do like bits of wire, KISS principle is the way to go. I have already heard a few more exotic stations so more amusement for the early evenings and dark nights approaching.

Post by **Stanley** » 28 Sep 2013, 04:28

It's a sub culture....

Off piste but I'll post it here in case I lose the site. Another drop out has just happened, not sure if this post will be successful.

Ten minutes later. All my other web connections are fine but the site server appears to be having a brain fart, keeps dropping out.....

Post by **PanBiker** » 29 Sep 2013, 13:21

I worked a special call station yesterday, a few lads operating from the site of the lighthouse on Arranmore Island, County Donegal. My first contact on the 40M (7Mhz) band in about 23 years. Can work this band now on my new bits of wire. Good signal into Barlick and got a good report back for mine as well.

melteaser · Post by **melteaser** » 06 Oct 2013, 08:22

Imindoors has worked the Arranmore lot from here in France. He says there is another one - Herm Island, Guernsey.

He has also worked North America, Algeria, Cuba, Canada and Madeira Island.

He also heard a pilot of a 737 operating on 20m while in there air from Spain to th Netherlands.

Post by **PanBiker** » 04 Nov 2013, 17:33

I have made the decision to build a ground tuner to provide an artificial earth for my station and have just started to gather the components together for the project. I'm going to build this, from a design by GD4EIP – featured in Practical Wireless Oct 1990.

Building a Ground Tuner

I have a few of the smaller components and I have just bought the variable capacitor that I need off Ebay.

It's a new dual gang 500 + 500pf capacitor, I will only need to use half (1 gang) of this for the circuit design.

I still need a suitable cabinet, the meter, the multi-way switch and the correct gauge of enamelled copper wire to make the coil. I will put more pictures up as I progress the design.

Post by **PanBiker** » 07 Feb 2014, 15:31

I bought this before Christmas from Ebay for the ground tuner project. It's a 100mA panel meter courtesy of the minions from the Peoples Republic of China. Took about 3 weeks to arrive but hey ho, a bargain at £3.99 with free postage from the far east.

Hard to tell on the photo but it's 2" x 1.5" and will mount nicely on the front along with the variable capacitor and a switch for the tapped inductor. I know the space I need now for the front panel layout so I can start to look for a suitable cabinet for the build.

Post by **PanBiker** » 28 May 2014, 15:09

I went to the NARS (Northern Amateur Radio Society) Blackpool Rally last month to look for some more bits for the ground tuner. I was specifically looking for an enclosure or cabinet of some description to house the project and the fairly heavy gauge ECW I need to create the tapped coil in the design, a 12 way SP switch was the final bit on my list.

The annual Blackpool Rally is held at the Norbreck Hotel in two of the large halls. There is always a full compliment of dealers and vendors of components along with representatives and stands from the various sub groups and societies within the hobby. When I was first licenced you could almost guarantee that you would be able to find anything you needed for a home brew project at a rally this size. I was quite dismayed to find that among the 100 or so vendors at the event none of them were selling cabinets or project boxes. There always used to be at least two custom box vendors at the rallies where you could find any size of alluminium box that you need to shove your latest masterpiece of construction in. Not a single panel bender to be found, not to worry, move on to plan B and a good rummage in the junk bins under the stalls.

After about three times round the venue looking under the benches rather than what was on them I found this:

Sorry for the dodgy quality of the image but this is a Pye Westminster mobile PMR transceiver as used by the Police way back in the 60's and early 70's. It's a 6 channel FM transceiver much loved by radio amateurs as the units could be easily modified to work on the 2M (144MHz) amateur band. This particular one has been converted and has four pairs of transmit and receive crystals for that band.

Here it is with the lid off:

and the simple front panel arrangement:

You can see that it's not the prettiest bit of kit but these did used to represent state of the art communications 50 years ago.

I found it languishing in the bottom of a big plastic bin on one of the test equipment and ex military kit vendors stalls. When I pulled it out and asked for a price the guy on the stall immediately came back with the the fact that it was working on 2 meters so must be worth a tenner. I told him I wasn't interested in the gubbins, I only wanted the case so offered him £5, he said that wasn't enough so I put it back and walked away. Nothing to be had anywhere else so towards the end of the afternoon I called back and It was still there. I lifted it up again and offered a different guy on the stall £3.00 for it and he almost snapped my hand off, winner, into the rucksack!

I was expecting to have to pay £20 - £30 to get a reasonable new cabinet so for £3.00 this has definitely got potential. It has a central platform chassis with transmit and receive circuitry either side. Once this is stripped out I will move the chassis to the bottom to create a more conventional box to house the ground tuner design. The front panel is a flat aluminium plate and can easily be replaced and drilled to suit the panel layout I need. Top and bottom covers have half turn locking screws on and are finished in a blue crackle type finish. I may well spray these up.

I could not find anyone selling short coils of 2mm ECW. I only need a loose coil of about 13 turns on a 38mm former so that is just about 1.5M of wire. I have found some on Ebay which I might order, 10M but the money I have saved on the case would pay for that still with change so it might be the best bet. No-one had a 12 way single pole switch either, plenty of 4 way and multipole but not what I need. I can get that online as well only a few quid.

These are the other bits and bobs I came away with, again sorry for the quality:

I saw my mate Geoff from Barlick on the SOTA (Summits on the Air) stand and he gave me a handful of the releasable cable ties that you can see on the left of the picture. Apparently the SOTA group were given a box full of these so they were distributing them free gratis to whoever called at their stall. Ideal for securing temporary cable runs or similar tasks. The other two bags are bargain buys, the top one is a mixed bag of plastic bits, there's allsorts in the bag, spacers, gears, nylon shims, nuts, bolts, washers, bits of cut plastic rod. I paid £1 for it, you could choose whichever bag you wanted with different mixes of sundry bits. The one at the bottom is a bag of mixed insulated crimp connectors another job lot for £1.00.

So all in all I spent a whole £5.00, Mick (of metalworking and woodworking fame) will be proud of me. I might make a start at stripping out the Westminster tonight. I might even be able to sell the matched crystal sets on Ebay, could end up making a profit on that £3.00 worth.

Post by **Tripps** » 28 May 2014, 17:29

Thanks for that post Pans. Brings back a few memories. I used to deal with AT's a lot in my previous existence, and often wondered where the hobby would go in the age of the internet. Were there many young people at the event? I think the average age of licensed amateurs was over fifty when I quit. Still - you're obviously still getting a lot out of it.

Post by **PanBiker** » 28 May 2014, 19:06

I think what you get out of any hobby is proportionate in some respect to the effort you put in. Amateur radio is so diverse in what it has to offer which is part of it's appeal to me. I enjoy building my own equipment helped along no doubt by my past lives in electronic and later computer servicing. Quite few younger ones apparent at the rally, the current licensing regime for entry onto the bands has certainly helped in that respect. The age range of licence holders though has been debated at length via the pages of Rad Com and is an ongoing issue which is raised time and time again at the RSGB annual conference.

Post by **PanBiker** » 16 Jun 2014, 23:15

A bit more work done on the ground tuner project. I stripped out all the component the other night from the Pye Westminster rescued from the junk bin at the rally which yielded these modules and sundry components.

This is a front view of the stripped out case with the front panel removed, you can see the centre mounting of the chassis.

Here is another view of the chassis showing all the riveted screw pillars for the various modules, there are a similar number on the other side of the chassis.

Here is the case with it's top and bottom covers.

Now all the components are out of the case I can see that due to the number of riveted pillars that need removing and the various existing cut outs and feed through hole in the chassis it will probably be better to replace this completely with a new chassis. I have a mate with sheet metal cutting and bending facilities so I will be sourcing a bit of sheet aluminium and paying him a visit at some point for a new custom made chassis. The chassis is only held in with rivets to the side frame. It will only need bending on three sides as I need a straight edge at the front behind the front panel. I also need it to be a little shorter front to back to accommodate the meter movement that will be set in the front panel. I will get him to cut me a new blank front panel as well, this is held by four machine screws in the front escutcheon. I think I will put a sheet of thin polycarbonate or perspex on top of this after lettering or annotating the front panel. I have used this method on a number of my homebrew projects, it creates a nice scratch proof finish.

The outer case components will require stripping and repainting, not finalised on a colour scheme yet. There is a rather fetching example of this design finished in Bugatti colours, maroon and black. I'll have a think about that.

I have ordered a few more of the bits I need from an online component supplier. I found a 10m reel of the 2mm ECW I need for the tapped coil and the 12 way rotary switch for the design. I have also ordered some suitable flanged knobs for the variable capacitor and the 12 way switch. Kicking myself a little as I realised shortly after placing the order that I have forgotten a 50K potentiometer that I need for zeroing the meter. I already have a number of pots but sods law say not the size I need.

So only parts outstanding now are the aluminium and perspex sheets and the correct sized potentiometer.

Post by **Stanley** » 17 Jun 2014, 03:37

Still Greek to me but very impressive. I like the way you start at the beginning.....

Post by **PanBiker** » 20 Jun 2014, 20:45

Part of my component order has been delivered, slight problem though. I ordered two sets of calibrated and pointer flanged knobs, 1 x calibrated and 1 x pointer knob in each pack. When delivered I only received the pointer knobs. I gave the customer service team for the firm a ring and they are sending on the calibrated knobs. I would appear that the items are incorrectly shown in pairs on the website but they will honour the order as shown. 2mm ECW that I ordered is currently out of stock and will follow when back on stock.

From Ebay I have ordered a sheet of 1.2mm aluminium for the new chassis and front panel and two sheets of plexiglass at 2mm and 3mm thicknesses. 2mm is for the front escutcheon and the 3mm for the variable capacitor mounting to isolate it from the chassis and for forming an insulated centre support for the tapped coil which will be 12 turns wound at 37mm diameter.

I'll drill the rivets out holding the chassis to the frame next so I can make a start on refurbishing the paintwork on the case.

Post by **PanBiker** » 25 Jun 2014, 11:33

I have got the old chassis out of the Westminster case and been looking at the clearances through the front escutcheon for the meter. The depth of the meter movement will determine how far back the replacement chassis will have to sit, the chassis height within the frame will be determined by the height of the centre spindle of the variable capacitor. A bit of measuring required before I ring my mate.

I had a delivery this morning which was the additional calibrated knobs that have been supplied FOC as they were shown incorrectly as pairs on the website. I have a card through the door for another parcel delivery that will not fit through the letter box. I think this will be the aluminium sheet that I ordered. Only thing still outstanding is the 2mm ECW which is on back order.

Post by **PanBiker** » 29 Jun 2014, 19:07

I have contacted my mate Geoff about bending up a new chassis and a front plate. He is just waiting on me now to suggest a mutually convenient time. I had and email on Friday to say my 2mm ECW had been dispatched so I am expecting this Monday or Tuesday. I have made another purchase via Ebay over the weekend but I'll report on that in the station thread when I have taken delivery.

Post by **Stanley** » 30 Jun 2014, 04:23

Slow but sure. OCD can be very useful at times!

Post by **PanBiker** » 10 Nov 2014, 16:22

Another minor enhancement to the station area that will make it a lot easier to do my construction projects and other practicalities. My half, (more like 25%) of the loft has not yet had any usable surface to do such tasks on. As I occupy a niche underneath the sloping roof line of the loft it is fairly difficult to get sufficient headroom underneath the main support purlin. I have addressed this with a small table which I have positioned under the Velux. This gives me a further niche to work in at 90 degrees to my station bench which has good light, (certainly during the day). I will fit some form of electric light and bring out a 4 gang power socket onto the back wall to provide for my soldering equipment and other power tools I may need.

The table actually started life at our first house when we had the kitchen extension built. It was a small 4 person dining set just right for when our first two kids were little. It sat at the bottom of the dining kitchen. When we moved house it was surplus to requirements as a dining set so the benches went and the table first went to my daughter in her bedroom and then to Dan in his, he used it for model building and such. Finally it went to our youngest lad Jack who used it for painting (spray and brush) all his war hammer figures that he was engrossed in as a teenager. So it's seen some action and was last used by Sally at the other side of the loft to support her knitting machine. I noted that she only used this once every blue moon or possibly more infrequently so managed (with a bit of considered reasoning) to get it redeployed in my corner. The knitting machine is portable job anyway so no real problem in the long run.

Here it is deployed, needs further enhancement as described above but does represent a quantum leap on the construction side of things. You can see the new linear power supply on there having a cursory inspection with the covers off

OneGuyFromBarlick

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