Rockwell Collins 718U-5M avionics HF SSB transceiver (AN/ARC-174)

This is the Rockwell Collins 718U-5M avionics radio installation (for HF bands), in fully operational setup. The radio covers 2 MHz to 30 MHz in 100 Hz synthesized steps. Frequency selection is done through toggle switches for each frequency digit. The radio allows for 9 user programmable non-volatile memory channels, which also store modulation mode. Programming can be done from the front control without restrictions.
The radio has a built-in automatic antenna tuner (Collins calls it a "coupler") which tunes anything from the proverbial coat hanger to long wire antennas. Tuning is done by means of two motorized vacuum capacitors and one motorized inductor. Tuning time is about one second on average, 2 seconds maximum. Re-tuning is done once the operator changes the selected frequency.
The radio has two audio inputs, one for a carbon microphone (or carbon simulating like the Telex 66T), and the other a 600 ohm balanced input for digital modems. Audio output impedance is 600 ohms with enough power to drive a 600 ohm communication speaker.
Required supply voltage is 28V DC at 22 amps peak (two tone modulation), 14 amps average (speech). During receive the installation draws about 3 amperes.
The 718U-5M consists of following sub systems:
-671U-4A receiver/exciter
-548S-3 amplifier/coupler
-514A-7 control unit, military designation C11289/ARC-174
-990C-3D mounting (for receiver/exciter)
-990C-2 mounting (for amplifier/coupler)

[@turnleft_]

Had the distinct privilege of working with this radio in the US Navy, SH-60B helicopter as an avionics tech. Back in the day, KC9CFI... I would take every opportunity to get out and play with this radio back in the day when I could get away with it!

[@ERICtheLATE]

Thank you for your service!

[@Spookieham]

I've never seen an HF aviation fit running outside an aircraft before. Great work in getting it running.

[@flynngallagherflightdept3858]

I operate a Falcon 50 (See my QRZ page, K7KSG) with a dual installation and have had both out twice for repair and they still will not tune. Sadly, there are no avionics techs around who know anything about HF systems anymore. That being said, I certainly enjoyed your tour of the radio components; I couldn't ask for a better guide. Thank you!

[@patc4947]

I worked for an airline in avionics.Its hard to be an expert when we work on so many systems,different aircraft. We had a lot more problems with the antenna couplers,tuners that is,receivers,panels were much more reliable. All were Collins.

[@mostlypostie1]

Thanks for showing us this - it's great to see this HF gear which is not seen often!

[@ricardosuarez8023]

What a great piece of electronics! Very advanced for the time it was made. Thank you for the review.

[@timforrestcet35]

Very nice video...Thank you, Sir! Brings back many avionics memories.

[@samiam5557]

Really cool, expensive & rare. Neat set up.

[@dang25272549]

Wow... very nice and unique radio . I guess it wasn't easy to put everything together and make it works. 🖒🖒🖒🖒

[@robertrockwell7581]

very neat radio it takes up a bit of space.

[@flyer617]

Now I just need to find one for my plane.

[@rogerhitchner6962]

What microphone do you believe would recreate the Rockwell Collins snarling audio effect ? The Telex 66T you mention or another ?

[@maninthevan53]

wow never seen anything like this lol, wow awesome

[@gianpietrogozzi1983]

please please please. I'm looking for the connections between RX/EXITER and PA of this rig. can someone help me? Thank you

[@LifeIsTooShortForQRP]

Give me an email address then I will mail it to you

[@dang25272549]

So cool !👍

[@VK2UAL]

I love that radio, I have always wanted an airliner Hf TX RX I would like to know did you have much trouble tracking it down ? I been looking on eBay and the like but not as yet. Keep up the great work, it is greatly appreciated. Regards Richard vk2ual

[@greenpedal370]

Keep an eye open now because civil aircraft are being scrapped like never before. Old HF radios will not be taken back into stock. They probably scrap them to recover the gold.

[@radio655]

Beautiful. How to get it into the avionics bay of your car?

[@LifeIsTooShortForQRP]

That would need a DC to DC converter from 12V to 28V. I actually bought such a DC converter ( a military one) that can handle the needed current, from this guy: www.ebay.com/itm/351720076674 This radio will actually work quite well mobile, you could mount the control box on the dash and the radio itself in the trunk, and the built-in antenna coupler can match a vertical on the car automatically for any selected frequency!

[@proudsnowtiger]

No conformal coating?

[@LifeIsTooShortForQRP]

Yes, the boards are all coated with some kind of protective varnish. Doesn't show on the video too well unfortunately

[@maninthevan53]

lol I notice the older transistors

[@ngawairangi3694]

Any cb radio side band For sale how much