Orbit Radio
 

Anyone remember Orbit Radios ? I've been out of the hobby since the early 60's. My last radio was an orbit reed. Good radio as I remember it. Just wondered what happened to Orbit and Bob Dunham owner.
Bob

RE: Orbit Radio
 

Be interesting to ehar other replies. My first propo radio was an Orbit and it was not a particularly good one. I went to Kraft and never had a problem. My guess is that bob had a hard time ajusting to proportional.
Walt

RE: Orbit Radio
 

A little searching found these scraps of info: In 1956, Bob was in LA, owned a hobby shop, and was producing the Orbit reed radios. Apparently jhe flew at Sepulveda Basin. Jack Albrecht and others mention getting help from Bob on radios around that time and place. Bob has passed away-have not found a date-and was enrolled in the AMA Ha;ll of Fame in 1999. Unfortunately, there is no biography posted at the AMA site for Bob. Wish there was more handy. I'd be interested, too.

RE: Orbit Radio
 

Bob only passed away recently. He was in a home about 80 miles east of Los Angeles. His wife is running an internet Importing business.

Wm.

RE: Orbit Radio
 

ACL Digilog
Bonner Digimite 8 & 4
C&S Digicon II
Controlaire Digital Proportional
Dee Bee Quadruplex CL5
F&M Digital-5
Kraft KP-6
E.K. Logitrol 5 & 7
Micro Avionics
MIN-X Astromite
Orbit 7-14 & 4-8
PCS (Proportional Control Systems)

A list of proportional systems in the 1966 RCM Annual Proportional roundup. There were a few other systems at the time. A period Kraft ad mentions that there were a total of 19 proportional manufacturers at the time.

Of these systems there were several significant designs and developments by different companies.

Bonner was escapements and reed servos from the early 50's to early 60's, so they were very well known. Howard Bonner won the nats in 1956 with the "Smog Hog" using a 5 channel CG Electronics radio. For those who don't know, 5 channel then was left, right, up, down, and throttle change high to low to high, etc. CG Electronics later became C&S (Bill Cannon).
The Bonner Digimite 8 used a slightly odd pulse scheme of double pulses to start and stop the pulse width for each servo. It was also quite bulky since it incorporated "fail safe" which doubled the component count, thus cutting the reliability in half. Remember this was the day before commerical intergrated circuits.

Orbit was quite well know for reed radios, starting around '57 with an 8 channel system. This was in the dark days of tube transmitters and tube receivers with maybe a transistor or two. Bob Dunham won the Nats in '57 with a Smog Hog with ailerons added to the Bonner design, and then in '58 with the new "Astro Hog" which brought on the low wing design to pattern competition. When proportional radio finally arrive, Orbit bought a analog proportional design and released it with their PS-1 servo. This may have been the first plastic cased servo. The analog radio was fading fast, as the Doug Spreng invented digital servo set the standard for the next 40 years. So Orbit came out with the 7-14 and 4-8 digital radios (a reed mindset in nomenclature) with the PS-2 servo that combined both a linear output with a rotary output. This servo set the standard from '65 to '67 with many others using it in their systems. Orbit was also the first radio system to use integrated circuits.

Doug Spreng and Don Mathes developed the first commerical digital proportional system, call the Digicon. It had problems with the receiver due to the pulse scheme, since each channel that was on for a period was followed by a long period that was off, so the receiver was open to noise - either RF or electrical. However about this same time the solution was developed by Frank Hoover of F&M Electronics. What he developed in encoding is still used today, which was a narrow off pulse to the carrier to show the edge of each pulse. With the narrow off pulse, the receiver was more immune to noise, since the AGC circuits had a nearly continuous signal. His Digital-5 radio also had failsafe circuitry.

Mathes, Spreng, and Jerry Pullen worked at various times for Kraft Systems. Phil Kraft was a very talented experimenter that developed RC radios (he wasn't an engineer) from the late 50's. Kraft and Pullen built a large number of digital designs going back as early as '63. But they sold very few because of the high standards of Kraft, possibly to limit exposure and risk. But after Mathes became involved, Kraft release a system without failsafe, both cutting the cost while doubling reliability. Kraft became the gold standard, and by 1968 came to dominate the industry with the famous Kraft Gold Medal radio along with their new KPS-9 and KPS-10 servos. They were also one of the first companies to use 4 cell nicad battery packs. Many of the earlier radios had 7 cell batteries with multiple taps for different voltages required by servo motors and circuity voltage bias. Naturally, some cell were drained faster than others.

E.K. radio was Elliot and Krause. Bob Elliot designed the amplifier for the Bonner Transmite servo, which was important as it started the transistion toward cheap gain circuits in RC equipment and also because it eliminated relays in the reed receivers. Relays were necessary before, because before transistor were cheap and available, amplifier gain was both expensive (took a lot of batteries to operate tube circuits) and bulky. Anyway, E.K. built a very nice radio and soon used the Orbit servo PS-2 mechanics. Significant developments at E.K. was the bridged servo amplifier which eliminated the need for a center tapped battery pack. Anybody that flew center tapped radios knew that if a cell died, or lost power, you might move a servo one direction, but not be able to move it back to center. This usually showed up as a spirl dive. This happen to an Orbit radio of mine in my first RC airplane - a Falcon 56. The other big developement from EK was the dual conversion receiver.

Mathes also started Micro Avionics, which was simular in design to the Kraft and Orbit radios. Started with the Orbit PS-2 servo and control sticks.

Kraft started PCS which was a repackage Kraft with fewer options. Kraft also sold a design to Heathkit for really low bucks, which strangely enough advertised the new Kraft KPS-9 servo before Kraft did. Kraft actually sold some Kraft KP-4 and KP-6 radios (Kraft Custom) with KPS-9 servo replacing the less reliable KPS-7 before the introduction of the Gold Medal series.

Well, that's all that comes to mind right now. 1964-66 was really a turning point in RC radio development. If you already knew all of this, it's a trip down memory lane. If you got one of these radios, I do a little collecting so keep me in mind. For those unfortunate people who expect their radios to work everytime - Welcome newbie.

RE: Orbit Radio
 

I think High Plains covered it all. I remember the first radio my dad purchased was a W.S. Deans 12 channel reed system installed in a VK Mach I powered with a Johnson .35 R/C. He pulled it out of the airplane and bought the then new Orbit Proportional which was Dunhams much improved Space Control. I learned R/C flying on a deBolt Cub with that radio and an OS .19 for power. He later purchased an Orbit 4-8 with the PS-4 servos and also had the Kraft Custom 6 channel single stick radio. From what I recall, both were excellent radios. Once Kraft introduced the Gold Medal Series, most of the club members made this their radio of choice. I'd love to find a complete Kraft Custom single stick, but like most of the older radios are very hard to find.

RE: Orbit Radio
 

Is theJack Albrecht you mention the one that used to be an officer in the army and stationed in Germany around 1970? If so, is there a way to contact him. I flew with him there for several years. Any help would be appreciated.

John Lingrel

RE: Orbit Radio
 

Yes, he was. Ended his career with Airtronics. The AMA web site says that he is still living in CA. He would be age 84 now. Perhaps the AMA could forward a note for you of offer some other help.
http://www.modelaircraft.org/museum/bio/albrecht.pdf

RE: Orbit Radio
 

Jack is a member of the Vintage R/C Society and can be contacted through the Yahoo Group http://groups.yahoo.com/group/VRCS/

RE: Orbit Radio
 

Boy, you guys sure bring back the memories.
High Plains & Mike have it right.....but you guys talk about the "Gold Medal Radio's" made by Kraft. Is that the same as the "Signature Series" radios made by Kraft that would have a person's name engraved on the front plate of the transmitter?? Now let me tell you the story of how I bought one of these thousand dollar Kraft radio's. I was at a farm auction one day and in this bucket of "junk" that the farmer was selling there was a model engine. It was a Morton M-5 radio five cylinder engine WITH a metal three bladed prop. I payed $125 for the bucket of junk and tossed the "junk" behind the farmers barn and put the M-5 on the seat of my pickup. It was frozen solid from setting out in the chicken coup all the years, but cleaned up nice. The metal prop shined up like chrome. After soaking for two weeks in kerosene I got it too turn over. Too make a long story short, I sold that M-5 to a guy on the east coast for the money to buy a Kraft Signature Series radio. Wish I had the M-5 back now.

I still have a Orbit single channel with a couple SN & Bonner varicomp escapments and a Orbit 7-14.
with servos. I started flying in the fifties with Wag equipment and a Rudder Bug. Still remember the serial number of those tubes like my army serial number.
See Ya
Jim

RE: Orbit Radio
 

MX,
The Kraft Gold Medal series radios were first produced around 1968 to replace the earlier Kraft Custom radios. The Gold Medal set the style for future Kraft radios up until the end of the line around 1983 or so. The Kraft Custom was available in either a two stick configuration with Bonner sticks or an open gimbal two axis single stick with the rudder pot on the top of the transmitter. The single stick transmitter was cradled with the left hand, the index finger operating the throttle and the thumb operating the rudder. The Gold Medal radios were a completely different design, incorporating the rudder control pot in the single stick, while the two stick version was a Kraft stick design available in either Mode I or Mode II. The Signature Series was introduced around 1976 or 1977 and was a special order radio. The value of these radios is relfected with Ebay prices and depending on the demand can bring almost the original selling price.

Kraft radios on Ebay are quite common but one must be careful on a purchase. Unless they are on 27mhz or 53mhz, the Gold Medal and Sport Series radios on the old 72 mhz frequencies cannot be narrow banded (due to circuitry and cost) but according to Pete Waters of KMI, the Series 1973 and later can be narrow banded. Any AM narrow band receiver can be matched and used with a Kraft transmitter and can be found on Ebay or other buy and sell sites. Futaba, Ace, Hitec and FMA narrow band AM receivers are the best to use.

The Kraft synthesized radio, the Channel Master was ahead of its time and can be the "Holy Grail" of Kraft radios. Ebay bidding can be heavy for these, the average selling price from between $300 to $600 . Most flyers around the club referred to them as "Dial-A-Crash". Maybe for that reason, potential buyers were scared away because of this attitude. Roll forward 30 years and look at the synthesized radios available from Futaba and JR. Kraft was ahead of its time and it is unfortunate that they could not compete with the cheap reliable radios coming from the Far East. BTW, the Channel Master unit with receiver can be used with most Kraft external plug in module transmitters.

RE: Orbit Radio
 

My first digital proportional radio was an Orbit six channel single stick purchased in 1961.

I found it to be as reliable as anything else at that time but did notice that more problems started after the attempts by Orbit to have the product assembled in Mexico.
I sold Orbit, Kraft, Proline, Royal,and EK in my hobby business. My personal preference was the Proline open gimbal single sticks. I used them in pattern ships and could transition from one transmitter to the next with no change in feel. The Kraft single stick units were ok but not as precise as the open gimbal Prolines.
Kraft did have a product that was much easier to produce as it was mostly molded plastic versus machined components. In fact at one time or the other all of the above radios used the Kraft single stick in their products.
The Orbit was an acceptable product but was bypassed by several others by 1974 on.

RE: Orbit Radio
 

A Kraft Custom transmitter KPT-4B from late 1967. Note the early "Kraft" transistor logo. This transmitter was available with either the open sticks with electronic trims, or the Bonner plastic stick assembly. (I guess that I should also note that you could also get it with the Orbit closed gimal metal sticks, but that is very rare.) The open sticks were prefered due to the +/- 45 degree throw (Bonner +/- 30), and the fact that the trims didn't move the stick like the Bonner. This transmitter was one of the early systems on 72 MHz. It weighs 2 lb, 11 oz and is rather thick at 2.6", with a 54" antenna.

RE: Orbit Radio
 

This 1967 system was one on the last ones made before the introduction of the Gold Medal series in early 1968. Normally, these systems came with the KPS-7 servo (metal case, linear rack with an output on either end or on the top in the middle). But the KPS-7 required quite a bit of maintaince to operate well (feed back pot and wipers needed service about every 25 flights or so). So since Kraft was gearing up for the introduction of the Gold Metal series, a few KP-4B systems were put out with the new KPS-9 servos prior to their official introduction.

Note the Kraft Custom receiver in a metal case. Connector technology was a bit crude at this point in time. Especially the huge battery connectors! Kraft solved this in 1970 with the Multicon connnector block and connector system.

RE: Orbit Radio
 

JACK ALBRECHT is living in Fairfield CA, (707)426-9422. He is still associated with Airtronics and they may have an EMail for him.
PHIL KRAFT is in a home somewhere in S. CA, probably around Oceanside.
BOB DUNHAM passed away longer than "recently" as someone commented. He lived his last years in Lake Havasu. AZ
ORBIT & KRAFT in their last years were both sold to non R/C companies who had no concept about the hobby and mismanaged both into the ground.
ORBIT SCHEMATICS. I have a complete file, from the single channel to the last. They are available, but except for single sheet ones, no EMail - it has to be Kinkos and the post office. Ask:[email protected]

RE: Orbit Radio
 

Hi,
I'm a little confused, I thought that Cliff Wierick held the pattens on the various systems that make proportional radio's possible, such as the digital feedback used in the servo's, etc. Cliff worked with Kraft for a period of time before a falling out, I heard it was about quality issues but not sure. In fact, Cliff's future wife, Charline Brown, AKA Charlie Brown, was the model used in the PCS ads.
This is the 1st I've heard that that Spreng and Mathes were involved in the development of proportional radios. I knew they were involved in manufacturing, but not the development.
BRG,
Jon

RE: Orbit Radio
 

I believe that Mr. Weirick worked for Bonner in the early 60's and flew Bonner radios in competition before his association with Kraft and PCS in the mid to late 60's. He did not have any patents in RC as far as I know, but then neither did Doug Spreng on the digital RC servo. At that time, there was more of a spirit of discovery and sharing of a hobby rather than an industry.

In an article written by Phil Kraft, published in the May-June 1964 issue of Grid Leaks, he talks about the early development of digital systems. From the article:

RE: Orbit Radio
 

Of course for a Kraft Custom radio, you need the correct airplane to go with it. As in the back ground, a Graupner kit of the Kwik Fly III.

RE: Orbit Radio
 

I used to had a Kwik Fli by Graupner and the KPS-9 servos back in the early 70s. Great airplane and Heath did a fair job of implementing the Kraft radio

John

RE: Orbit Radio
 

I dunno, Kwi Fli or Ugly Stick. I'm afraid I lean toward the Stick.
Walt

RE: Orbit Radio
 

I was looking for an article for a friend and ran across these. Bob Dunham on the cover of MAN October 1964 and an Orbit propo ad that ran in MAN in 68 and 69.
Oops, clicked OK before I added the pics.

RE: Orbit Radio
 

The Orbit ad shows three Orbit servos, the PS-2, PS-3, and PS-4. PS stood for "Proportional Servo". I think that the PS-2 was the first modern digital servo (in terms of design, materials, and construction) and was widely used in the 65-67 time frame by many RC companies. Here are pictures of the Orbit PS-2 servo mechanics in the Orbit black and Logictrol red plastic. Not a small servo, it's measures 2 3/8 X 1 1/4 X 1 7/16 at 2 3/4 oz. It has both a rotary and a linear output, with about 4 1/2 pounds of thrust, and moves like molasses in January.

For comparitive purposes, a Hitec HS-225 (roughly the size of the PS-4), shows how Orbit was driving servo development in the 60's.

RE: Orbit Radio
 

I hate to date myself, but I guess it just comes with age. Some of my earlier experiences included flying with huge transmitters and receivers (by today's standards) that used vacuum tubes. I used to live in the LA area and knew Bob Dunham when he had his shop in Lynwood. I bought one of the early single channel Tx/Rx (no escapements or servos) from him and flew a Jr. Falcon with it. I used a Bonner escapement, Cox TeeDee .049, and I was able to ROG, fly around successfully, and land in front of me after the engine ran out of fuel. Later, I bought an Orbit single stick proportional system from Bob and was very happy with the results. I still have the Orbit radios and Bonner escapements. Bob was one of the nicest guys and he was very patient with people coming into his shop, asking about R/C.

I flew at Mile Square field in Fountain Valley in the days when we had to go to the El Toro Marine base to get the key to the gate. I had one of the earlier gold box Kraft systems with the open gimbals. That was a great system; very reliable. Occasionally, Phil Kraft and Joe Bridi and others would come to the field and show us all how our planes should fly. I remember flying various Kwik Fli versions as well as the Jensen Stiks. Fun times.

Last fall, just for nostalgia sakes, I ordered a set of plans for the Jr. Falcon from AMA and built it with a few mods. I installed a HiTec system with HS81 servos and an OS LA .15 for power. It's been snowing for some time now, so I'll have to wait a month or so before I can take it out.

It's fun to hear from you all and your experiences in the early days. It's one thing to fly these creations we have today, but it's also fun to build a nostalgia plane. I ordered a set of plans for the Playboy Sr. from Bob Holman, so that looks like it'll be a fun plane at the field this summer.

Lee

RE: Orbit Radio
 

The guy who taught me to fly back in 1971 had an Orbit radio probably dating back to early mid 60s. Said the paid $600 for it, think of that in todays prices. It was proportional but was it big.

RE: Orbit Radio
 

My first radio was a Heathkit Blue Box. Wonderful radio never had a bit of trouble with it. Started with KPS-9 servos and they took a big plane to fit, since they were the same dimension 3 side by side and lenghtwise. Later added the KPS-12 servos, something like 15 transistors on one little circuit board. Didn't worry about servo reversing, just take the back of the transmitter off and switch the leads on the stick pot. When I built it, I wired the switch wrong and failed the smoke test. Sent it to Heath and they said it had a bad circuit board and sent me a factory assembled one for free. Oh and had 4 wire servos but the offered a conversion later to 3 wire.