MILITARY COLLECTOR GROUP POST, JUNE 2/98 Index: UNIVERSAL INVERTER POWER SUPPLY, PART I; by Dennis Starks MEMBERS WRITE; Missouri Barn Load/T-217, ON THE COMMERCIAL FRONT; Haney Electronic Co. Museum Down Sizing List, TCS Stuff; HUMOR; *********************************************** UNIVERSAL INVERTER POWER SUPPLY, PART I; by Dennis Starks FORWARD: The below series will be essentially the same material that is to be sent out with the copies of the PRC-6 manuals that Ralph Hogan is making available. If you have ordered these, you will be getting it again, along with schematics, and block diagrams. If you are able to receive graphics via email, Ralph has the ability to send you copies of the schematics, and block diagrams. The material should be in his hands shortly. If you have not ordered PRC-6 manuals, and are not able to receive graphics via email, you can still contact Ralph at for hard copies. GENERAL: This power supply is capable of operating almost any vintage tube type radio, either receiver, or low powered transceiver that had originally been intended for battery powered operation. Only minimal modification will needed to this basic circuit to serve your needs. Input voltage requirements varie depending on the radio in question, type of transformer used and your choice of power source. Some particular radios that this supply has been used with include; GRC-9 or BC-1306 receiver section(90-105volts), PRC-6(45 & 90volts), CPRC-26(45 & 90volts), GRR-5 receiver(90-105volts), PRC- 8,9,10(67.5 & 135volts), BC-1000(135volts), BC-611(90-105volts), many old Motorola "Handie Talkies", and a host of others. The completed inverter, can be built on to a board that measures as small as 1.5" wide x 1.75" long x .75" tall, making it small enough to fit inside nearly any radio leaving ample room for rechargeable batteries. NOTES(refer to schematic) #1)Transformer considerations(T-1). Any 88mh, or even 44mh toriod type transformer can be used and your added primary, and feed back windings will remain the same. However there will be some types better suited to your particular application, and with the dwindling availability of these transformers, it's best to use only the one you actually need and save any others for later. Unless you have some rather sophisticated test equipment, you will not be able to tell these transformers apart. So if you should go to all the trouble of winding one, and placing it in an operational circuit only to find it's the wrong one, fear not! Just set it aside, and wind another one, the first will still be useful on a future project. Several types of 88mh toriods can be found, they include dual 44mh(two windings), single winding 88mh with a center tap, and single winding types that do not have a center tap. The dual 44mh, and those with a center tap are the most versatile as they will provide dual output voltages without the need for outboard voltage dividers, or regulators(either of which would eat up efficiency). The dual output voltage is obtained by connecting the two 44hm windings together so that they are in series, thus producing a center tap that will provide 1/2 the total output voltage. If yours has a single winding with a center tap, this job is already done. As can be seen, this is of major advantage when working with radios like the PRC-6,7,8,9,10,26 etc. All of which require two B+ voltages one being 1/2 the other. So do not waist these type transformers on say a BC-611, or GRC-9 receiver which only require a single B+ voltage. The second type 88mh toriod you might find is the single winding type. These are not well suited to radios that require a dual B+ voltage because to obtain the second(lower) B+ voltage, a resistive voltage divider, or regulator must be used. Neither of these alternatives are acceptable due to the extreme efficiency loss they will produce. And when we consider the battery supplies that we may often be restricted to, this efficiency must be kept high at all cost. These type transformers will work where a single, relatively high output voltage is needed but a minimal voltage source is available. One case in point is the BC-611, here we need only a single operating voltage 90-105 volts to operate the radio, but we have at best enough room inside the radio for 4.8vdc if 4ea "D" cell nicads(5amp hour) are used. This will be just enough! The third toroid type you might encounter will be the 44mh variety. The output voltage they produce will be about 1/2 that of the 88mh types for same input voltage. They will usually not have dual windings, or a center tap. Their best application will be with radios who's operation will not be tightly regulated by the type primary power source available, and those requiring only a singe B+ voltage. In most these cases an external supply, either battery pack or 12vdc automotive source will be used, with very little if any need for space conservation. These applications come to mind; GRC-9 or BC-1306 receiver section, RS-1/GRC-109 receiver, GRR-5 receiver, RS-6 receiver, RT-70 transceiver,etc. So as can be seen, if you wind one of these, then find it will not suite your needs, fear not, it will someday. Transformer construction; Transformer winding is not at all critical. Suiteable wire can be salvaged from old audio transformers, coils, etc. Due to the very small typical size of these transformers, complete insulation between each of the windings will not be possible. Start with a short length of masking tape(or whatever you prefer) that has been cut to the same width as the transformer. Wrap it around the outside edge of the original existing winding(secondary) one full turn. Insure you don't cover up it's leads. All the following coil windings should be done in the same direction as the existing coil(secondary). Next wind the Primary(transistor's Collector winding), it's 48 turns of No.24 enamel wire center tapped at 24 turns. Finish by again wrapping a single turn of insulating tape around the outside edge. Last is the feed back coil(transistor's Base winding), it's 18 turns of No.28 wire center tapped at 9 turns. Then wrap a couple layers of tape around the finished transformer. Again, only around the outside edge. If you screwed up and wound the feed back winding first, no big deal, it will still work anyway. #2) Transistor Considerations; About any pair of transistors that are the approximate equivalent to an ECG-104 can be used. Due their physical size, and the minimal power dissipation in this application, no heat sinks will be required. When using these type transistors, R-2[between the primary & feadback wingings center taps] will typically start out at 1000 ohms, but when using some hamfest, or junkbox transistors, this value may need to be reduced to around 500 ohms. In applications where there are no internal space limitations, the ECG-104 type devices will do just fine. Some radios however, like the CPRC-26 and BC-611, will have minimal internal space to house both the inverter, and it's batteries. In such cases I prefer to use TIP-41 type transistors due to their much smaller size, even when the required heat sink is taken into account. The same basic circuit is used, but the polarity of the primary power source is reversed, and the value of R-2 is reduced to about 100ohms, or until the circuit starts to oscillate. VOLTAGE REGULATORS; Two voltage regulators are needed for each one of our inverter power supplies with few exceptions. The first is needed to supply our heater voltage needs. As the heaters in all types of battery powered tube type radios are very fragile, their voltages need to be regulated to insure their protection and proper operation. Resistive voltage dividers are a bad choice for several reasons, #1 is the extreme heat that will be dissipated by the large power resistors needed, and along with that the associated efficiency loss. #2 the growing rarity and expense the size resistors needed. #3 Their large size will waist precious internal space. #4 And most important is that there is no regulation available. The later is VERY important! Tube heaters do not present a uniform load to a power source. This is because when they are cold, their resistance is very low which will produce a correspondingly high current drain. As they heat up, this resistance raises, and with that, the current drain is reduced. When a simple resister is used to drop the heater supply voltage, it will do no voltage dropping until a load is presented, I/E the voltage(be it 12vdc) on one end of the resistor, will be the same(or 12vdc) as that on the other end until a load is connected. So essentially, the very low cold heater resistance will absorb this 12vdc(surge current) until they have a chance to heat up. In the case of the very small heaters in these radios, they will have no chance to heat up. It's easy to see what will happen to a 1.5 volt tube when it is exposed to 12vdc even if for a fraction of a second. They'll pop like a flash bulb! The second regulator is connected to the input of the inverter so as to allow some sort of output voltage adjustment and regulation. This and the heater regulator also provide for a much wider variety of power sources. I/E, a basic power supply for a PRC-6 only needs 4.8 volts, but with voltage regulators on both the inverter supply and the heaters, either the radios internal 4.8 volt batteries can be used, or any external power supply of 6-30vdc can also be used without modification or adjustment. A further advantage is in that only one battery will need be fabricated, but it might then be usable in several different radio types. I/E if you make up a 10vdc battery for your PRC-6, this same battery could be useable in your PRC-10. A simple variable voltage regulator circuit is presented here using the very common, cheep, and versatile LM-317 regulator IC. It will serve all our needs and many others. CONSTRUCTION NOTES; The inverter, and regulators should be constructed on separate boards using your preferred method. PC boards have been designed, and may be made available in the future. PC construction will be of advantage where space limitations need be observed, or production of multiple units is desirable. Otherwise Perf board construction will do just fine. If you design your own PC boards, DO NOT include a common ground on the inputs, or outputs of either the inverter or the regulator boards, nor allow any common ground connection on the boards themselves to be incorporated in any mounting method. This is because in many cases input or output connections must be kept above ground to either isolate voltage polarities, or to effect proper power on/off switching utilizing the radios original circuits without modification. Heat sinks will be needed on the inverter transistors only if TIP- 41 type devises are used, even then very little is needed. The LM-317 voltage regulator IC will also require heat sinking. ECG-104 type transistors can be mounted directly to your PC, or Perf board. Dennis Starks; MILITARY RADIO COLLECTOR/HISTORIAN military-radio-guy@juno.com Parts List:(inverter) Q-1, Q-2, ECG-104, or TIP-41 transisitors.(see text) R-1, 15 ohm resistor. R-2, 1000 ohm resistor.(see text) C-1, 20 mf/25vdc electrolytic capacitor. C-2, 5 mf/200vdc electrolytic capacitor. D-1, -2, -3, -4, 1N-4001 rectifiers. T-1, 88 mh, or 44mh, toroid coil.(see text) Parts List:(regulator) U-1, LM-317 voltage regulator IC. D-1, -2, -3, 1N-4001 rectifiers. C-1, -2, 10 mfd/35vdc electrolytic capacitor. C-3, .01 mfd disk capacitor. R-1, 5000 ohm, PC mount potentiometer. R-2, 220 ohm 1/2 or 1/4 watt resistor. Related Topics: MCGP Backmail #32, Alternate Power Sources; The Ultimate Universal Inverter Transformer? & Typical Radio Power Requirements. by Dennis Starks More Inverter Design Discussion; by Mark Gluch, & Dennis Starks Nick's Inverter Transformer Input; by Nick Broline RE: DC-DC; Ralph Hogan, & Dennis Starks Pete's Inverter Transformer Ideas; Filement types? *********************************************** MEMBERS WRITE; Missouri Barn Load/T-217, Hi Dennis, I found a couple of goodies over the weekend, in a barn "somewhere in Missouri". A NOS crated up PE-103 with power cables (but no radio cable, damn it) and even the bag with spare brushes still attached, and also a complete RC-291 (RM52 & RM53), including manual and canvas bag, although only one T-17 mic, and no headsets. The bag and manual were new to my collection. The fellow also had a real boatanchor that someone else might be interested in: a T-217 Collins built rack mount 225 to 400 MHz ground to air transmitter, and the associated power supply/modulator unit. Each of the two units is about 4 inches taller than an R-390, and probably weighs 50% more as well. He also had what appeared to be complete T.O. set for the system. It appears to have twice as much gearing in it as an R-390, so I'm not too excited about it. In fact, is anyone interested in that 225 to 400 MHz stuff? If so, they can contact me. I think the price would be reasonable. 73, Sheldon KC0CW ed) personally, I wouldn't take the T-217 as a gift, in fact I've turned several down. But maybe someone out there is more masochistic than myself. *********************************************** ON THE COMMERCIAL FRONT; Haney Electronic Co. J-45, leg iron CW keys, Correct for BC-1306, GRC-9, GRC-109, and PRC-47. These are new old stock units most still in original packaging, several contract dates from 1968 to 1980's. They include cord CD-201A with PJ-055B connector. The member price is $20.00ea. AS-2975, PRC-70 dipole antenna kit. Unused Similar to that use with the PRC-74 differing mainly in the balun it uses. The member price is $25.00ea. H-250 handsets, new, latest issue. $17.50 ea U-229 audio connectors, $1.00ea U-77 audio connectors, $2.00ea PRC-25 or 77 battery connectors, removed from battery, with white plastic spacer. $1.00ea PRC-70 Selector assembly, unused, forest green. NSN 5820-01-092-5904, also called the A1 module. This is part of the front panel, with 6 frequency select knobs, and readouts, controls for power, mode, volume, and squelch. Includes printed circuit board with microprocessor. $60.00 STEVE HANEY ed) Steve has a list of manuals available on request via email. ---------------------------------------------------------------------------------- Museum Down Sizing List, The Louisiana Museum of Military History, due to financial realities will be will be moving to smaller quarters. We have been asked to help liquidate some of the Commo gear. Below is the first list of equipment that's been made available. If you have an interest in any item contact Joe below via email and he'll pass along any needed info. AM-1780, untested but good condition, $ 25 AM-2060, with cable, $ 95 AS-2851, 30-80 log periodic complete, $ 125 BB-451, NOS with electrolyte kit, $ 185 BB-451, used, $ 100 BC-639, untested but good condition, $ 35 CPRC-26, with most accessories, $ 70 CU-2267/GR, Five unit multicoupler - with two spare F-1482, $125 CY-6121/PRC-74, Wet cell battery box, $ 25 DY-105, untested but looks good, $ 45 DY-105, no dynamotor, $ 25 GRA-71, almost complete, $ 125 GRC / VRC, lots of cables, ASK GRC-109, details later GRR-5, ASK MD-522, with cables, $ 100 PPS-4, complete except for optical sight, $ 300 PRC-25, with accessories, $ 300 PRC-41, with antenna / PP-3700 AC supply - working, $ 175 PRC-68, with handset, antenna and battery - working but a little rough, $200 PRC-68, with handset, antenna and battery - working, good condition, $ 235 PRC-77, with accessories, $ 350 PRC-90, with battery - working, $ 100 PRC-90, with battery - no 282.8 transmit, $ 50 PRR-9/PRT-4A, working w/manual copy, $ 50 R-392, good condition with power cable, $ 200 R-442, working, good condition, $ 225 RT-524A, unchecked, $ 300 RT-524A, working, $ 500 RT-68, no meter, $ 40 RT-858/PPS-6, RT only, Make offer Russian 62R1, VHF cargo pocket transceiver with mike and dipole wire antenna - ASK Make offer Russian R-105M, no accessories, $ 100 Russian R-108, no accessories, $ 100 TRC-77, untested but good condition, $ 75 TS-323, good condition, $ 35 TT-722/TG, untested, $ 50 ITEMS NOT FOR EXPORT All reasonable offers will be considered All items plus shipping Payment to: Glen Thibodeaux c/o Louisiana Museum of Military History P. O. Box 92110 Lafayette, LA 70509 Glen is looking for PRC-64 accessories, G-43 or G-58 generator and M-1 Carbines / accessories. If folks would just contact me directly, I will take care of getting things to Glen. Joseph W Pinner EMail: kc5ijd@sprintmail.com ---------------------------------------------------------------------------------- TCS STUFF; ed) I'd have liked to hagle a little with this guy, but when he starts out with a price like this, I get turned off. You try him. I saw your ad in Amateur Radio Trader. I will sell or trade. I am looking for American Flyer S Gauge Trains or 2m ham gear..HT or Mobile no crystal models... Type Ser# Mfg. TCS 9 Receiver 3433 Collins Radio TCS 9 Transmitter 3433 Collins Radio TCS 9 Manual NS# TCS 13 Receiver 1945 Hamilton Radio Corp TCS 13 Transmiter 1945 Hamilton Radio Corp TCS 13 Control Box 1945 Hamilton Radio Corp TCS 13 Manual 1945 Hamilton Radio Corp TCS A C Power Supply Collins Radio TCS Cables R-100/URR Receiver UNK PE 101 C Dynamotor UNK No end caps BC 221 AH Freq. Meter 7823 No Case I 151 A Oscillator( MOD 101) 334 Espy Mfg Co NY NY All the radios are complete, unmodifed as far as I can see, cosmetically the TCS's have paint flaking on cabinets,1 unit has bent equipt pulls,1 unit has some masking tape on it, the power supply is missing 1 of the chokes, the cables are very stiff & one is missing a plug. The R-100/URR is complete ,but not working, it is OD paint and has stamp w/sig corp & (27148 PHILA 19944 03). The serial numbers are correct for the TCS 13,as well as the TCS 9. My name is Al Eisenhaur N1PIC, Cape Cod Ma. I am asking $600 For the lot + shipping. *********************************************** HUMOR; Here's some of Rodney Dangerfield's best one liners... A girl phoned me the other day and said Come on over, there's nobody home. I went over.Nobody was home. If it weren't for pick-pocketers I'd have no sex life at all. And we were poor too. Why if I wasn't born a boy.... I'd have nothing to play with. During sex my girlfriend always wants to talk to me.Just the other night she called me from a hotel. One day as I came home early from work ..... I saw a guy jogging naked. I said to the guy .... Hey buddy .... why are you doing that for? He said .... Because you came home early. Its been a rough day. I got up this morning .... put on a shirt and a button fell off. I picked up my briefcase and the handle came off. I'm afraid to go to the bathroom. When I played in the sandbox the cat kept covering me up. I could tell that my parents hated me.My bath toys were a toaster and a radio. My mother never breast fed me. She told me that she only liked me as a friend. My father carries around the picture of the kid who came with his wallet. When I was born .... the doctor came out to the waiting room and said to my father .... I'm very sorry.We did everything we could ...but he pulled through. My mother had morning sickness after I was born. I remember the time I was kidnapped and they sent a piece of my finger to my father. He said he wanted more proof. Once when I was lost..... I saw a policeman and asked him to help me find my parents. I said to him ..... do youthink we'll ever find them? He said ... I don't know kid .... there are so many places they can hide. On Halloween .... the parents send their kids out looking like me. Last year... one kid tried to rip my face off! Now its different...when I answer the door the kids hand me candy. My wife made me join a bridge club.I jump off next Tuesday. I worked in a pet shop and people kept asking how big I'd get. I went to see my doctor.Doctor, every morning when I get up and look in the mirror... I feel like throwing up;What's wrong with me?He said... I don't know but your eyesight is perfect. My psychiatrist told me I'm going crazy.I told him .... If you don't mind I'd like a second opinion. He said .. Alright....you're ugly too! When I was born the doctor took one look at my face ... turned me over and said.Look ... twins! I remember when I swallowed a bottle of sleeping pills. My doctor told me to have a few drinks and get some rest. ---------------------------------------------------------------------------------- ABBOTT AND COSTELLO MEET WINDOWS 95 Costello:Hey, Abbott! Abbott:Yes, Lou? Costello:I just got my first computer. Abbott:That's great Lou. What did you get? Costello:A Pentium II-266, with 40 Megs of RAM, a 2.1 Gig hard drive, and a 24X CD-ROM. Abbott:That's terrific, Lou Costello:But I don't know what any of it means!! Abbott:You will in time. Costello:That's exactly why I am here to see you. Abbott:Oh? Costello:I heard that you are a real computer expert. Abbott:Well, I don't know- Costello:Yes-sir-ee. You know your stuff. And you're going to train me. Abbott:Really? Costello:Uh huh. And I am here for my first lesson. Abbott:O.K. Lou. What do want to know? Costello:I am having no problem turning it on, but I heard that you should be very careful how you turn it off. Abbott:That's true. Costello:So, here I am working on my new computer and I want to turn it off. What do I do? Abbott:Well, first you press the Start button, and then- Costello:No, I told you, I want to turn it off. Abbott:I know, you press the Start button- Costello:Wait a second. I want to turn it off. Off. I know how to start it. So tell me what to do. Abbott:I did. Costello:When? Abbott:When I told you to press the Start button. Costello:Why should I press the Start button? Abbott:To shut off the computer. Costello:I press Start to stop. Abbott:Well Start doesn't actually stop the computer. Costello:I knew it! So what do I press. Abbott:Start Costello:Start what? Abbott:Start button. Costello:Start button to do what? Abbott:Shut down. Costello:You don't have to get rude! Abbott:No, no, no! That's not what I meant. Costello:Then say what you mean. Abbott:To shut down the computer, press- Costello:Don't say, "Start!" Abbott:Then what do you want me to say? Costello:Look, if I want to turn off the computer, I am willing to press the Stop button, the End button and Cease and Desist button, but no one in their right mind presses the Start to Stop. Abbott:But that's what you do. Costello:And you probably Go at Stop signs, and Stop at green lights. Abbott:Don't be ridiculous. Costello:I am being ridiculous? Well. I think it's about time we started this conversation. Abbott:What are you talking about? Costello:I am starting this conversation right now. Good-bye. ---------------------------------------------------------------------------------- YOU MIGHT BE A YANKEE IF: 1) You think barbecue is a verb meaning "to cook outside". 2) You think Heinz ketchup is SPICY. 3) You don't have a problem pronouncing Worcestershire sauce correctly. 4) For breakfast, you would prefer potatoes au gratin to grits. 5) You don't know what a moon pie is. 6) You've never had grain alcohol. 7) You've never, ever eaten okra. 8) You eat fried chicken with a knife and fork. 9) You've never seen a live chicken, and the only cows you've seen are on road trips. 10) You have no idea what a polecat is. 11) You don't see anything wrong with putting a sweater on a poodle. 12) You don't have bangs. 13) You would rather vacation at Martha's Vineyard than Six Flags. 14) More than two generations of your family have been kicked out of the same prep school in Connecticut. 15) You would rather have your son become a lawyer than grow up to get his own TV fishing show. 16) Instead of referring to two or more people as "y'all", you call them "you guys", even if both of them are women. 17) You don't think Howard Stern has an accent. 18) You have never planned your summer vacation around a gun-and-knife show. 19) You think that more money should go to important scientific research at your university than to pay the salary of the head football coach. 20) You don't have at least one can of WD-40 somewhere around the house. 21) The last time you smiled was when you prevented someone from getting on an on ramp on the freeway. 22) You don't have any hats in your closet that advertise feed stores. 23) The farthest south you've ever been is the perfume counter at Neiman Marcus. 24) You call binoculars opera glasses. 25) You can't spit out the car window without pulling over to the side of the road and stopping. 26) You would never wear pink, or an applique sweater. 27) You don't know what applique is. 28) You don't know anyone who has two first names. (i.e. Billy Bob, Joe Don, Bobby Ray, Ronny Gene) 29) You don't have doilies, and certainly don't know how to make them. 30) You've never been to a craft show. 31) You get freaked out when people on the subway talk to you. 32) You can't do your laundry without quarters. 33) None of your fur coats are homemade. 34) And finally, you might be a Yankee if, none of this seems the least bit humorous to you *********************************************** (The preceding was a product of the"Military Collector Group Post", an international email magazine dedicated to the preservation of history and the equipment that made it. Unlimited circulation of this material is authorized so long as the proper credits to the original authors, and publisher or this group are included. For more information conserning this group contact Dennis Starks at, military-radio-guy@juno.com) ***********************************************