Chris Downing

Aha! Thanks chaps. Yes, I made a typo on that Tx frequency. My table does in fact say 35.130 for channel 73. 🙄 Great! That explains it. Probably many people don't know about the IF frequency adjustment to give the actual Rx crystal frequency, so many internet posts don't even mention the Rx being a bit different to the Tx. I remember reading that my Micron receiver is designed for Fleet, Futaba or Micron branded crystals, so FCS makes sense now. Probably, I ordered channel 73 specifically when I bought the receiver kit, so it would match my transmitter. Time fuzzes the memory a bit, eh? Good to have this collection of knowledge across our members!

Hi, I hope this is a suitable topic for this question. I need to identify this crystal. I have had it stored for some time in a bag along with a new (at the time) Micron Mini receiver I built. The Micron receiver is a 35MHz type so I assume this crystal in the bag is for this receiver. However, I can't identify what it is. It is a plain metal can with a clear, silicon-feeling heat-shrink tube around it. The writing says FCS 73R on one side and 34.6750MHz IOD W on the other side. My old RM Digicon transmitter has a channel 73 crystal in it, which going by frequency tables is 35.193MHz. What relationship does this new crystal have? Is it correct for a channel 73 receiver? Is the receiver crystal always a bit lower than the Tx frequency? The tables I see do not mention a receiver frequency.

AH- Yup. I know what you mean. I had to do a lot of searching to get all of the required footprints and 3D models, then edit some of them. To do any work in a reasonable time you really do need the popular modules to be available. BTW, I just found the Gadgets and electronics forum and there's a lot of interesting stuff there. That'll keep me in thought for a while.

Yes, Terry did publish his Tx circuit diagram in Radio Modeller in agreement with their publishing, although the mixers had only the theoretical circuit-parts. That was fair, I think, as most people would buy a kit to build them. I still have the original articles from 1986. There were a few pages missing from later in 1986, but Gangster was good enough to email scans to me, so I have the missing pages now. I haven't seen EasyEDA but now I have learned enough of Kicad to work with it I'm very happy with it. I found out later how to import 3D models of parts and I eventually was able to produce a full 3D view of each mixer board. Here's the three channel mixer (VtDeltaFlpCar). It's amazing what these CAD programmes can do, eh? By the way, the view here is from after I learned more and added all the component names into what is called the 'silk screen' layer. The PCBs I made were simply plain board with the tinned copper tracks on the back. It was fun but I think I would rather get into building something with balsa and plywood now!😉

I thought I would update my prior post about the RM Digicon mixer cards. This may be of interest to other keen RC electronics members. After giving up for a while, I got back to the idea and decided to go all out and complete my RM Digicon system by making the two mixer cards. I haven't enjoyed RC electronics so much for years. I now have some new PCBS and I just finished making my RM Digicon mixer cards! I'm very happy. It happened like this. I discovered the Chinese online PCB makers who can make several PCBs for only a few pounds or Canadian dollars. The only trouble is that they all require 'Gerber' files. Gerber files, I learnt, are a mainstream standard for CAD/CAM production (Computer Aided Design/Computer Aided Manufacturing). A far cry from the old school methods I knew from the 1970s and 1980s. These files enable automated machines to create PCBs "en masse" at low costs. I found a small programme to download that converts images to Gerber files (ImageToGerber) and so I converted the Digicon mixer card images in my magazine pages to Gerber files and tried submitting them to to one of the PCB manufacturers. Hmm. No luck. They were not able to make the boards from just the copper traces They wanted an 'edge cut' file and a 'drill hole' file and 'silk screen layer' file and more! I did explain that the PCB pattern on my Gerber file had a thin copper line around it that defined the edges, but they didn't understand that. So I found a free electronic and PCB CAD programme called Kicad on the web and tried to learn that. Wow, it's quite a complicated programme, but also very comprehensive. Now, the normal path of work in this programme is to draw a schematic in one part of the programme then translate that to a PCB layout with all connections already made. Then you drag components around to fit better and adjust copper track thicknesses to suit. It was all quite mind-boggling for me at first but I persevered. It took a while to get the hang of it but I knew I didn't need a schematic in there, with all the other functions, just PCB design. First, I found how to import my Gerber image of the PCB traces into its PCB editor. Once my new Gerber file was in the new programme, I found out the image conversion I had used was likely going to work because this Kicad programme's 'Gerber Viewer' recognised it as a copper layer! I also realised that the conversion created hundreds of small points around the edges of my copper tracks. This made the tracks appear with rough, zig-zag like edges instead of smooth, even lines. See attachment 1 'RoughTracks.png'. Hmm. I decided to ignore this at first. I then exported this to the Kicad PCB editor. Nothing showed up! Hmmm. So I read up about this and discovered there are several file extension naming conventions for the Gerber files. I changed the file extension from gbr to gtl and tried exporting this from the Gerber Viewer to the PCB editor again. Aha. This time a rectangle appeared in the programme, but not as I expected. See attachment 2. All I saw was a small blue rectangle outside the drawing area. What the heck? I tried again several time with the same result and eventually discovered that this really was my copper track layer. When I clicked on it a track outline showed up! In fact all the tracks were showing up with a slid covering across the whole PCB; hence the solid look. The positioning was due to it not having any recognisable or compatible co-ordinates. I found I could select all the items of the rectangle and move them down into the drawing area. Then I clicked on different parts until I found a whole rectangle, which, obviously did not belong. I deleted it and suddenly there was my PCB pattern With this achievement I realised the tracks still looked awful and rough when I zoomed in. I began a long process of zooming into one edge at a time, selecting a point then deleting it. Boring, depressing and my wrist hurt. But eventually I had a rather clean image of my copper tracks, just like Terry Tippet's original magazine image but now in the CAD file. I don't know if the rest of my progress would be boring to other members so I'll leave it there right now. Let me just say I moved on step by step until I had the required files to send to the manufacturing company, and they made me some nice, clean PCBs, ready to assemble. I'm quite chuffed at finally having my Digicon system complete after all these years. Thanks to Terry Tippett for a great design which I enjoyed building in the 1980s and just enjoyed finishing now!

In the December 2020 issue, on page 39, isn't that aircraft captioned an 'HP Halifax' actually a Wellington? Sure looks like one to me. My Dad flew in Coastal Command Wimpies, so I thought I knew them quite well. (Great magazine though, as usual; well done,)

Does anybody remember Bullens on Rayner's Lane in Rayner's Lane itself. It was the local hobby shop for my Dad and myself in the late 1960s to 1971. I can find NO mention of it on the internet at all. That was where we went for anything- trains, planes and toys. We bought a KeilKraft Phantom control-liner there and the diesel fuel we needed, plus a tank etc, etc. Maybe someone who lived there too will remember it?

Wow- thanks to everyone who has responded! Some good info there. One of the things I have found as time has gone by is that, although I value the work I have put in and want to finish it, I almost consider it a write off now, in monetary terms. It owes me nothing. So I'll be extremely happy to finish it, and when the time comes to fly it, I won't be too sad if it breaks. But .. it won't crash, will it- we're all positive about flying aren't we? Just always carry a bin bag in case ?. Glenn, Yes, the landing speed is quite high for the full size so it makes sense that this model would have some characteristics of the full size spit, even though Mick designed it to be easier to handle. Nice picture, by the way. Rich, thanks for tip on soldering and interesting stuff from the Ripmax modellers handbook. I always loved poring over the old catalogues, like the old KeilKraft etc. Foam wings- yes, Now that I have made a few contacts here recently, I will see what they think and suggest. They may be able to help me make a new set. I did draw outlines of the tip and root sections, and all the parts, on paper before starting assembly years ago, so in theory a new core could be made form the templates I drew. Cheers!

Does anybody know anything about a Mick Reeves Spitfire kit that I was given in the late 1970s as a birthday gift. I built the fuselage and wings in the subsequent years but it was slow going because I had no experience. My Dad was ex RAF in the war so was keen to get us flying an iconic WWII fighter. I never finished it, due to complexities that I could not overcome. After moving to Canada in 1991, my parents managed to safely cushion the fuselage and wing and bring it here! Sadly it has sat on a shelf since then, but I have not given up. I am about to try learning to fly (again) with my trainer. Then.. who knows. I just found the instructions and was surprised to discover it was a Mick Reeves Models kit. The kit is near-scale with an obechi-covered foam wing, 60" or 63" span (I haven't measured it yet.) Bent wire landing gear was provided and with hardwood, slotted blocks to mount the wire. An option was shown to modify the blocks to fit retracts (Carl Goldberg I think). My local model shop had only Comet Retracts from MicroMold, so I modified the blocks to accept those (over months). I bought a brand new OS Max III 60 HF GR at that time (late 70s or early 80s) and fitted it to enable forming the cowl. Since being in Canada, over the years I at least looked at the landing gear, which was a simple coil-spring chromed-wire type. I gradually found some alloy tube plus some plastic tube and made upper and lower oleo cylinders on one leg. Much better than the original wire. Also added shims to the bearing blocks to remove a lot of play (the plane wobbled terribly on the legs). The wing veneer will need fixing because it has cracked and separated over the years. The only wing joining bandage sold in the MIddlesbrough model shop back then was a very coarse weave, and after the resin cured I had to sand and sand for weeks (months?) to get the edges feathered and the surface reasonably flat. That put me off fibreglass for years. Back then I had an idea to hide the unsightly look of the huge OS silencer by using a header (blue, seen in the pictures) and connecting that via silicon tubing (I had just read about it) to a box silencer which I would make from aluminium, inside the fuselage. I would then installing scale exhaust stubs onto that box. Trouble was, I couldn't find aluminium sheets in that area and didn't know how to bend it or solder it. I had tried soldering aluminium and the solder just balled off. I had grand ideas but no experience, so time went by as I scratched my head. No internet back then, or modelflying site to help. Hope this sparks interest or memories !

Sorry to reply to this topic so late - only just renewed my subscription after some years - but, by any chance, does anybody have unused PCBs for the Micron/RM Digicon plug-in mixer cards? There was a Vt delta flp car and a DIF AIL CAR pcb . I built the system from the Radio Modeller articles in the 1980s and still have it. I was using it for driving a boat around at a lake here in Canada a few years ago. It always bothered me that I had not "finished" the system by making the plug-in mixer cards, so I am now looking into it. (Covid boredom triggered it.) I have found a source for most of the components, although the Piher potentiometers no longer have the reformed lead versions to match the PCB holes, only the 5mm spacing type; those would do though. I cleaned up one of the pcb images from the magazine article (in MS Paint!) and sized it to fit my transmitter encoder board, but now it seems a huge headache to make the pcb. I haven't masked and etched a pcb for many years! (Don't have any supplies either.) Maybe, I thought, someone has had both of these tucked away for years and never used them? It's worth a try asking. Cheers, Chris ActSize2 Micron DeltaFlpCar MixerPCB.bmp DifAilCar MixerPcb--uncleaned.bmp

Just for interest, did anyone else have an Aeropiccola spring powered engine starter? I just came across the old instructions from mine. I bought this from a model shop in Middlesbrough, in the 1970s, because electric starters were too expensive. Strongly made from metal, this starter worked by winding the front up a few times then positioning it on the spinner or prop nut and pressing the trigger - wang! It sort of worked but my engine was stubborn, so I performed hundreds of wangs trying to start this engine and ended up with sore fingers from repeated winding up! I would leave it a day or two to recover then off I went again. Attached is the instruction sheet ( hopefully I am not infringing any copyright by posting them here; if Aeropiccola are still in business this should be a nice thing for them to see one of their old products highlighted).

This is my A-M 15 diesel. I thought I had posted a picture some years ago but cannot find it now when I search. My Dad was given this, around 1969, for the Keil-Kraft Phantom we had just built. We were told it was a 15 and thought it meant 1.5cc, as required by the plan. Later we realised this was actually 2.5cc! That's why the plane was nose heavy. The needle valve assembly was broken so we bought a generic replacement (from Bullens in Rayners Lane. I believe). We never got it to run continuously- just short spurts after priming. So the plane never got airborne.

Don, I too remember the resist pens and etching process for PCBs- it was rather exciting waiting for the copper to etch and 'develop' your traces!  A bit like developing prints from your photo enlarger- but that's another story!  Edited By Chris Downing on 28/11/2010 22:10:18

Stephen, I missed your post while finishing my last one- good to see a beginner reading the thread! I hope you are enjoying reading this stuff.Actually I am still a beginner even though I have been reading RCM & E for many yearsI finally managed to get airborne last year (2009) and made one landing in tall grass- using a buddy box and a very helpful chap on the other end!  So - a beginner for many years but still very keen and determined.Just think - if  RC flying can keep me interested through these years then you will have a lot of fun ahead!  Edited By Chris Downing on 20/11/2010 23:35:43 Edited By Chris Downing on 20/11/2010 23:36:11

Of course, as soon as I had the Microtrol AM unit ready,  the FM systems took over and everything changed to 35MHz!I fancied building the RCM&E FM system when the articles came out but it was too soon after my  Microtrol. So I waited and then Radio Modeller published their FM 35MHz system in the 1980s, designed by Terry Tippet of Micron RC. I ordered kits for this system, as I followed the articles month by month, and this time I had an oscilloscope to help test it, although ironically this system could be tuned without one, whereas the Microtrol system could really have used one! The Radio Modeller (Micron) system was very good, with a centre-loaded aerial and strong, reliable transmitted signal, plus silky-smooth sticks.  I built the miniature version of the receiver and both this and the transmitter were designed around IC chips, whereas the Microtrol used separate transistors and timing capacitors.  I used this system first in my attempts at flying a semi-scale Aeronca Sedan, bought second hand.  Then in the 1990s I built a a Great Planes PT20 trainer and made my first attempts at getting off the ground with that, using this gear.  I couldn't get off the ground although I did get a young fellow to make the plane's maiden flight using this same RC gear.  Now In Canada I bought a Futaba T9C (FF9).  Finally I own a famous brand that I drooled over in the late 60s and 70s!   Ironically, I bought this 72MHz Futaba system in very recent years and by the end of that same year 2.4GHz had taken over.   At least I can plug a 2.4 module in the back if I want to upgrade.  Not much point in building my own gear now because the cost of RC has come down so much in real terms.  

Ah -lovely things!  I remember adverts for many of these RC systems etc. in RCM&E and Radio Modeller.  I could never afford the "real" Rc systems in the magazines so I built my own. My first contribution here is my first home built system- designed by someone else but built from kits, a few pieces at a time, as I could afford them. This one was in the 1970s - a Microtrol 27MHz AM system from a design by Paul Newell. I bought the book and used the schematics and instructions, together with many sub-kits of pieces bought from a model shop in Sunderland. I remember being thrilled as each small, brown parcel arrived in the post!  A joystick kit, another joystick kit; a Tx circuit board, a Rx kit with separate receiver and decoder boards. I eventually built this system, complete with charger and 4 servos (FB-3 mechanics from Skyleader SLM)   I had to tune it with a bulb and pick-up coil.  I never got my plane off the ground with this  but later (1990s) I put it into a model boat and got some use out of it!.  

Thanks David--Just the ticket!

OK- all of the old RC gear probably is off topic in this thread but I like to see it and read about it, so I think everyone with interesting gear like this should start a special thread or section of the forum just for this sort of thing. David Ashby started a historic  RCM&E section somewhere-- maybe he could start off a section for old RC gear (or maybe there is one already- can't find it though), so we can find it all in one place.  Edited By Chris Downing on 11/11/2010 23:28:52

I just looked on the home page and I don't see ithe propeller selection guide.  I'm sure it was there earlier this year but I didn't need it then.Now I do and it's gone- typical of life- if you don't use it you lose it!  Edited By Chris Downing on 11/11/2010 23:15:27

I have tried this dip in canada and It was great for putting a new rubberised coating on pliers etc. However-  I found the surface of the liquid in the tin begins to dry very quickly while it is exposed to air!   It is supposed to dry like this of course, but be aware that the tin of remaining liquid can become unusable after  a few goes, due to dry film on the surface and around the edges.  It worked best for me when I used a lot in just a few goes rather than using a little in many jobs.  

Thanks all of you for the suggestions- I initially found the instructions a bit less than clear; they go through set examples rather than explaining each menu entry in detail, so I really couldn't figure it out and gave up.After reading your suggestions I got the idea and tried it and... it realy is as simple as that!! I first tried simply assigning channel 5 and channel 7 to the same switch and your recommendation is simple to set up; I gave each channel different end points and when the switch is flipped, each servo goes to its (different) preset positions .  Then, because I wanted to change gyro sensitivity for my application, I opened the Futaba's GYRO SENS menu (page 2 of the advanced menu) and set it to use channel 7 (arbitrary choice) then assigned it to switch E. I also have channel 5 (gear) assigned to switch E.On a quick test, when I move the gear switch, the gear servo moves to its own positions and.... channel 7 servo moves to the different preset values I set up.  I also noticed that if you select the SERVOS feature from page 2 of the basic  menu you can see the channel movements graphically as you operate the switch.   Thanks again for the help! I wonder how many of us with these computer radios are confused by the instructions and simply use them in basic mode??  

Thanks  Steve- it's good to get input from others.Thanks to both you and Olly for reading the post and replying.   The best approach then is to not rely totally on frequency hopping to prevent all interference but to use a different frequency for a co-existing system, like video transmission or other data link.   

No answer seems to have come forth yet.I can add something...the reason is a need to operate a switch to change a channel between two values and at the same time change a helicopter tail-gyro remote-gain setting between an active value and  zero (i.e disabled) when the switch is moved.