Comm 2 has died. Is it worth replacing?


Pattern Altitude
Dec 14, 2011
Kent, UK
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My KX-155 Comm 2 has died. I have an Avidyne 540 as Nav/Comm 1.

The 540 can have up to 4 standby frequencies lined up, and can also listen in on both the active and first standby frequency. Given that all I ever use Comm 2 for is checking the ATIS, and the 540 has this monitoring function, I'm debating whether it is even worth replacing Comm 2. It would be $4k+ for a new Nav/Comm, plus installation.

The only thing I'm giving up is a little redundancy. It could be argued that having a back-up radio and ILS option is valuable.

Interested in the thoughts of the crowd!
I had thought about a repair, but I'd be looking at a couple of grand and it's still a 30-year-old radio.

I'm re-doing the panel soon, with a new metal panel to replace the current Cessna plastic, and if I do away with Comm 2 then that gives me more space in the center stack to move the transponder over; it's currently over on the right of the panel.

If I did keep a second Nav/Comm I'd go with a new one, rather than keeping the old King tech.
Used KX155 are all over the place for $1,500 or sometimes less. And you'll eventually get some of that back when you get your new panel.

All you would need to do is slide the old one out and the new one in.

If it were me, that's what I'd do...
I'd want a NAV/COMM #2, especially at the price point people are mentioning here.
4 standby's do you no good if the radio fails. In VFR, I could care less. In IFR, and especially long flights in remote areas like you seem to enjoy, I would care.
I like having a second nav /com don’t have room in my panel For one.
Someone just posted a KX155 for sale for 1k on PoA. I would swap it out, I love the KX155, if I had space for it and could swap another one in, I’d do it.
I saw those! Unfortunately my aircraft is 28V and the 155s for sale are 14V.
I saw those! Unfortunately my aircraft is 28V and the 155s for sale are 14V.
If you can find one, 28v 155's seem to be a little bit cheaper than 14v.

Yours wouldn't happen to be a 155a, would it?
Good question. I'll need to pull it out and look next time I'm at the aircraft.
Spruce is listing the KX-200 pre-order for ~$4,200, no install cost as it's a slide in replacement for the KX-155/165. Allegedly will ship this year, already approved by the FAA.
I want a second nav/com for back up.

I mainly use my second for checking ATIS, but also for monitoring 121.5 in flight. 1) In case I miss a frequency change and they try me on Guard. 2) If I am about to bust a TFR and they call me before launching the fighters.
I think yes it is worth replacing.
When my original 2nd radio started to fade a few years back (RT-385), I replaced it with a Michel/TKM MX-385 (slide-in pin-compatible replacement) that I found used on eBay, then sent back to TKM for service to get back into new condition. And total cost was less than half the price of a new one. Hundreds of hours on it so far, no problems.
Does Michel/TKM make a slide-in replacement for your KX-155?
The main purpose for having 2 Com radios is to have a backup in the case that your primary fails. This would be the reason to get the KX155 replaced. Listening to an ATIS frequency is an added bonus. If your audio panel is not wired to monitor the standby frequency in the Avidyne, then that would need to be added. It is not like some radios that you push a button and monitor the standby frequency. It is actually a separate input into the audio panel, which is often wired to the Aux button or something like that. By FAR the cheapest way for you to get complete again is to buy a used KX155. That should not cost much more than $1,000.
With your kind of flying, I'd highly recommend a second unit. As others mentioned. Having the capability to listen to numerous frequencies does you no good if the unit itself fails.
A second comm radio is good backup, even if it rarely gets used. I've been on a cross country where both comms, both navs and the adf all died in flight....
Also a good idea to actually transmit on comm 2 occasionally. It’s no help to find out when you need it that the only things it’s transmitting is garbled static.
A second comm radio is good backup, even if it rarely gets used. ...
Agreed. I also like having a second comm to streamline workflow. Makes it easier to keep the next frequency you'll need queued up for standby, while also actively using 2 other frequencies.
Some VFR folks may think "why bother, that doesn't apply to me", but even VFR, it's helpful if you fly in or around complex airspace.
If you shop around, you could probably find a 28v no-glideslope model (the cheapest version) for under $1k, especially if you didn't care about cosmetics.

I got a fancy Garmin comm with all the monitor/memory functions a while back and thought I'd never use my comm 2 again. I was wrong. I still need it.

IFR? I'd surely want a second COM. A COM is your lifeline if the GPS/COM crumps. The NAV is an important navigation bonus. Having said that, my GNS-430W has never completely crumped (although the vertical guidance board died at one point), but is sure is nice to know you have a COM and a backup VOR/LOC/ILS when in IMC.
I've had separate comm1 and comm2 failures a half dozen times in multiple planes in my short 450 hours of experience. I vote for doing what needs be done to keep that comm2
Another vote for replacing it

I’m VFR only, but I like having a comm2 radio as a backup. When I had my comm1 replaced, I asked the shop to wire the comm2 connections to jacks on the panel. I plug my handheld Yaesu into those, as well as an external antenna, and use it for a comm2 radio. The performance is acceptable, and I like that the Yaesu has internal batteries to take over if aircraft power is lost.

Also, my handheld will track a VOR, though the CDI display is difficult to see in sunlight.

If you already have a handheld, that approach might be an alternative for you until you’re ready to spring for a new radio to go into the panel.
Considering the world travelling you do, I would not feel comfortable only having one com radio. I would also not be comfortable having all my navigation and communication eggs in one basket as it were. I would want a second nav/com.