Rockwell Collins 618T-3 avionics HF SSB transceiver full restoration

This is a video of a full restoration that I did for the Collins 618-3 HF SSB avionics transceiver. The Collins 618T is a true vintage engineering marvel worthy of preserving. The first ones of these entered the market around 1965, after a 3 year engineering effort by Collins. It was produced all the way into the Eighties, after it was replaced with the fully solid state 628T radio (also shown at the end of this video).
The Collins 618T radio might look like an unappealing black box, but it is one of the most innovative and iconic transceivers Collins has ever produced. It paired versatility to superb reliability and as such it was used in almost every larger airplane of the time (the B747 had two of them installed), including the military. Numerous units have been sold; it was one of Collins most successful products. It also was used in many land-mobile and stationary applications, both military and civilian. Collins started the design for this radio during the early Sixties and the result was way ahead of its time.
The 618T was the first automatic compact HF SSB transceiver that Collins came out with. A radio that can cover the full shortwave range from 2 MHz to 30 MHz in 1 kHz increments, fully auto-tuned. The user only has to set the desired operating frequency from the remotely mounted control box. As such, the radio can generate 28000 user-selectable frequencies, all locked against a high-stability master oscillator with an accuracy of 0.8 PPM.
Keep in mind this radio was designed before the availability of digital dividers or digital synthesizers, it is all done in a fully analog design. A truly superb design effort, especially when you consider the limitations of the available technology at that time. Today's engineers have it much easier. You need to design an SSB radio? Grab some DDS chips from the web-based databook, and some DSP's with the software library for RF processing already done by the chip supplier, and off you go...

[@Comm0ut]

Lovely example which looks far better than the ones I worked in OV-10A Broncos in 1982-84. They provided USAF HF comms throughout the Cold War. They were respectably reliable.

[@JA-fy1bn]

Beautiful!

[@Ra_dio_Iberico_ea4ggc]

Que Maravilla de Equipazo Collins 618T yo los trabaje en los Douglas DC-8/50/55/63 y súper 63 después me vinieron los Boeing y cambie de Flota a los B-727/200 de la Iberia-LAE Si ingrese en 1969 como TMA pero era INGENIERO DE TELECO+ Electricista de Aviones y tenia 20-años, Mi Padre era Ingeniero Mecánico de Vuelo en los DC-8 Así que todo se quedaba en la Familia, el me Enseño Mucha MECÁNICA de Motores (de Coches y Aviones) yo le enseñe mucha Electrónica también Ahora estoy ya RETIRADO. Un Fuerte Abrazo de un viejo Amigo Español y Gracias.

[@LifeIsTooShortForQRP]

Thanks, appreciate it!

[@BGTech1]

Thanks so much for this. It’s so hard to find information about these boxes. Luckily I got a few for tear down videos.

[@LifeIsTooShortForQRP]

Tear-down sounds ominous... Would they be put together again afterwards?

[@BGTech1]

Yes, of course. It’s just to see the inside

[@ae1tpa92gwtom2]

Always like yr videos,.. 73 from Bahrain

[@LifeIsTooShortForQRP]

Thanks! 73s from Florida

[@ae1tpa92gwtom2]

@@LifeIsTooShortForQRP one of my favorites was the FT107M

[@chrisdick9860]

That radio is Goals , maybe one day I'll be lucky enough to find one

[@samw2195]

Lovely job ! All ways wondered about that high pitch whine you get from some HF aviation radios don’t hear it as much as you used to I know it won’t be that turbo fan (noisy bugger) as the main set would be in the avionics bay

[@RonanCantwell]

Fantastic job with the restoration. The radio looks immaculate! That fan is pretty full-on though 😂 I guess the main unit would normally be tucked away where it wouldn't be such a nuisance.

[@LifeIsTooShortForQRP]

Yes, you are correct, the transceiver would be in the avionics bay, far away from the pilots. They would only deal with the control box. I have a sound proof headset (used normally in helicopters which also are very noisy) which keeps the noise out great, but unfortunately my camera has no input to pipe-in the audio directly, it only has a microphone. Maybe I can fix that by buying a new camera, then I can make a better video showing the actual receiver performance (which is quite good) without all the noise. Cheers.

[@fecklesstech929]

I taught the USAF introductory (3-Level) theory & maintenance course on these back in the 1980's. I also taught it's cousin the ARC-105 which was the exact same radio except pressurized for high-altitude use. There were different power supplies available for them but the ones I worked on were configured for 115VAC/400Hz/3-phase aircraft power. We had special outlets in our classrooms to run them. Despite their electro-mechanical complexity they were very sturdy & reliable and easy to maintain due to the modular design. They were too noisy though. The fans just screamed. A dozen of them running in a classroom was painful. Interestingly enough, my tinnitus sounds exactly like a 618T blower! Go figure. I remember ops-checking these from the flightline on C-130s with the long-wire HF antennas. In good conditions I could get voice radio checks from all over the world on 8.989MHz and 11.176MHz USB, which were busy USAF channels back in the day. Great video. Thanks for the memories.

[@LifeIsTooShortForQRP]

Hello! I always love to hear from people who have actually worked with this equipment professionally, thank you for that. You are correct, the Military designated this radio the AN/ARC-102, and the ARC-105 for the pressurized version. Cheers.

[@samw2195]

They still used those frequencies and a few others hearing quite a few stations around the planet Croughton being the closest to me

[@albertcorda8185]

Hi! This is a wonderful video!... I just picked up some PULS SL20 supplies for a 618T-3 I'm trying to restore, and want to parallel them as you have...however, the very small amount of documentation I've been able to find on the SL20 supplies has conflicting info on how to set the parallel jumper... the one short document I found says first to install a jumper in the "P" position, but then contradicts that by saying if no jumper is installed, the supply will "current share"... may I ask how are your SL20 jumpers configured? Thanks! KX4JJ

[@LifeIsTooShortForQRP]

Hello! Here you can download the manual for the SL20: products.pulspower.com/us/sl20-110.html When you leave the jumper out (or put it in the "parallel" position, which is idle) you are in parallel mode. It makes the output of the SL20 "softer", so the current will distribute amongst the parallel supplies better. Of course this assumes you did set all units at the same voltage when unloaded (27.5V for the 618T-3), before you tie them together, otherwise it won't work. Hope this helps! Cheers.

[@RayOvacRadio]

👍

[@BGTech1]

These where used on many Boeing 727s and early 737s

[@robertrockwell7581]

nice radio but that jet engine would drive me nuts. stay safe.

[@LifeIsTooShortForQRP]

Robert, thanks!

[@royw73]

Je hebt het over een jumper om ze in parralel te schakelen.. jumper verzetten onder in door het gat in de voeding? Vanuit PA 73

[@LifeIsTooShortForQRP]

228 / 5,000 Yes, that's right, the manual explains it (you can download the SL20 manual from the web). It is one of those small jumpers encased in plastic, which they often used for computer hardware in the old days. If the jumper is removed, the power supply is "softer". All you have to do then is adjust them all for the exact same voltage (without load), and when putting them in parallel. Use the same DC wire length for all 3 power supplies. then the current will distribute nicely across the SL20 supplies. 73s.

[@vincecox8376]

That's funny back in Vietnam we called it the ARC102.

[@LifeIsTooShortForQRP]

Vince, you are correct, the military designated this radio the AN/ARC-102. In what plane was it used then? Or did you use it land-mobile, maybe as the MRC-95? Cheers.

[@hene193]

Nice radio. Did you delete the russian radio video? It was the best available in English.

[@LifeIsTooShortForQRP]

Yes, I did, sorry. Given all the current turmoil with Russia, I was getting nasty remarks about it. Weird thing is, I noticed Ham Radio Outlet does not sell the Discovery TX-500 any more, maybe they also were getting a lot of flak about selling a Russian product. Who knows. Cheers.

[@hene193]

@@LifeIsTooShortForQRP Oh that sucks. Well maybe in the future you can upload it again.

[@vincecox8376]

CH47 Helicopters and C-130 aircraft

[@LifeIsTooShortForQRP]

Thanks!

[@steven351]

🤘 𝘱𝘳𝘰𝘮𝘰𝘴𝘮

[@justinellison4214]

Very noisey it is!