KX-155 Refurbishment, Replace??

sourdough44

sourdough44

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I'm kinda looking into getting this radio to a higher level, or replace. I'm kinda looking at sliding something into the existing tray?

Here are my main issues, 1st the screen is buggered up, lights half out. I have to almost count the clicks to get to the correct freq, kinda a pain in a busy environment.

It takes a long time to warm up, 5 minutes or so before it works as advertised.

Then after all is said & done, ATC says 'loud & clear' when I do a radio check. This has G/S and I think is a KX-155, USA made. My 2nd radio is an old KX-175, not any better.

Do they still make new KX-155s? I guess I may think more about the ADS-B upgrades? GTN-650 or so?? Will a KX-165 slide in? I'm not ready for immediate action, but I can see some upgrade in a few months. Just looking for ideas.
 
I looked over my KX-155 today. It does look a little played out. I think I need more than just a refurbishment. I have a few more things in the hopper, then on to the radio.
 
The gas discharge displays in the King radios is a known problem. Both the 155 and 165 suffer from that. King apparently has an LED fix for the gas discharge display, but it ain't cheap - not much less than the price used KX-155s are going for. If you have more than display problems with the radio I suspect your lowest cost solution is to find a used King 155 and swap it. They are still pretty popular, especially as a Comm 2 to a Garmin nav/comm/gps.
 
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Won't hurt to give these guys a call for a quote: http://www.butleravionics.com/

We've had them refurb autopilot servos, the HSI gyro, and a KY 197. Pricing was reasonable and the work was done correctly and on time. I'll happily go to them next time for King refurb work.
 
I flew the plane to VT the other day, got a little more used to the radio. The LED readout would come & go with how readable it was, sometimes not to bad. ATC never has any complaint with the radio quality. I think for the near term I'll just make do the way it is.

I would hate to spend the $$ on a radio with an unknown background. Some look like they may be in questionable condition.
 
I have a KX125 and am really happy with it, not sure if they slide in to replace. Display a lot more reliable.
 
Well, I decided to go one round with a simple swap out. This 'new' radio has a much newer serial number with an excellent display. I just need a dependable radio to get me down the road a bit.

We'll see how this goes. Once in place I'll sell my older 155 with the so-so display.
 
You can clean the display connector to get all the display numbers to display correctly. Just did it on mine and it worked like a champ. google and you will find details. it is easy.
 
I did try the 'eraser' cleaning method, no real change. With slow ops freq changes I could figure out the led screen, just didn't want to have to do it all the time.
 
I'm still looking for a CHEAP 155 so that I can phiddle phart with the display to see if I can mod it to LEDs. If I can, I'll sell a kit for not a lot of money.

Jim
 
weirdjim said:
I'm still looking for a CHEAP 155 so that I can phiddle phart with the display to see if I can mod it to LEDs. If I can, I'll sell a kit for not a lot of money.

Jim
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Jim, I have one that died, it's at the radio shop now, if they say is not economically worth fixing I will send it to you.

Bob
 
unsafervguy said:
Jim, I have one that died, it's at the radio shop now, if they say is not economically worth fixing I will send it to you.

Bob
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I'm happy to buy it, pay the postage, whatever you think is fair.

Now the question is ... does anybody have a source for a schematic or even better the service manual for this turkey so I can see how they drove the display in the first place. Otherwise I'm going to have to use the Polish Mine Detector method of discovery.

Jim
 
weirdjim said:
[snip]Otherwise I'm going to have to use the Polish Mine Detector method of discovery.

Jim
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That made me laugh out loud. Been there, done that.

John
 
last year I replace both displays on my C172. When I did my avionics upgrade to my planes I moved the Garmin 430 to the Cessna and one of the 155 to the bonanza. I also placed my PSI audio panel into the Cessna. I wanted to put the GDL 88 from the bonanza to the Cessna; however, the cost of time was to great and I put the L3 ADS_B transponder into the Cessna. None note for the L3, the voice annunciation of traffic was $700 plus installation. Beware that it is useless without voice traffic to permit you to keep your eyeballs outside.
 
winrose46 said:
None note for the L3, the voice annunciation of traffic was $700 plus installation. Beware that it is useless without voice traffic to permit you to keep your eyeballs outside.
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Holy smokes, that had to be near $10k then for parts and labor just for that one radio.
 
weirdjim said:
I'm happy to buy it, pay the postage, whatever you think is fair.

Now the question is ... does anybody have a source for a schematic or even better the service manual for this turkey so I can see how they drove the display in the first place. Otherwise I'm going to have to use the Polish Mine Detector method of discovery.

Jim
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I have the MM for a KX155A which uses a different display but it's still plasma. The interface has serial row and column data plus clocks. The column signals are 5V TTL levels but the row stuff switches between -180 and -190 V.
 
gismo said:
I have the MM for a KX155A which uses a different display but it's still plasma. The interface has serial row and column data plus clocks. The column signals are 5V TTL levels but the row stuff switches between -180 and -190 V.
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That negative row stuff is going to be a *****. I suppose I can get down to TTL levels using a resistive divider if I keep the current to a minimum, but how to invert a negative signal to a positive signal without a negative supply ... I suppose I could diode switch into some sort of PNP inverter to get the thing turned around ... so much for a trivial design ...

Jim
 
weirdjim said:
That negative row stuff is going to be a *****. I suppose I can get down to TTL levels using a resistive divider if I keep the current to a minimum, but how to invert a negative signal to a positive signal without a negative supply ... I suppose I could diode switch into some sort of PNP inverter to get the thing turned around ... so much for a trivial design ...

Jim
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I sent an email to tech@rstengineering.com (I think that's you) with a copy of the KX165A display board schematic and a sketch of a level translator that should bring those HV outputs back to logic levels. An alternative would be to piggyback on the connector feeding the display signals from the main board but that might prove challenging mechanically.
 
Find a replacement. Bendix-King no longer supports their product. They stopped manufacturing the plasma displays, so unless you can find a shop that has some, if a display goes out, start shopping for a new radio. BK abandoned their GA GPS customers over a decade ago, not they're letting their GA NAV/COM go as well. They're going the way of the Dinosaur (Narco). Mitchell says they are working on bringing a slide-in KX-155 replacement to the market, but last I spoke with them was in early 2015 and haven't seen it yet. If and when the bring it, they'll own the replacement NAV/COM market, since most everyone that has a decent Hybrid panel has a KX-155 as number 2.
 
Honeywell markets the Blue Donuts in King's name. They got Blue Donuts, just no repair facilities for old products or a product line to trade up into.
 
gismo said:
I sent an email to tech@rstengineering.com (I think that's you) with a copy of the KX165A display board schematic and a sketch of a level translator that should bring those HV outputs back to logic levels. An alternative would be to piggyback on the connector feeding the display signals from the main board but that might prove challenging mechanically.
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Yes, and I've got a couple of questions that I'll pm you about. Some stuff I don't understand, but then again, the last time I played with anything over 28 volts was back in high school when I was fixing vacuum tube TV sets. jw
 
murphey said:
TKM announced a new version of its 155 slide in replacement last week at SnF.
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It looked really good. $3k estimated price range and have just started the certification process, so they estimated first units ship late this summer.
 
murphey said:
TKM announced a new version of its 155 slide in replacement last week at SnF.
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They will not work with the Garmin G5 HSI interface as currently defined. That is totally dependent on if Garmin will be adding old analog radios to the interface or not. My guess, is not.
 
murphey said:
TKM announced a new version of its 155 slide in replacement last week at SnF.
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I saw that and wasn't a fan at all. The old KX155 knob scheme is much faster than having to touch the screen and twist two different knobs. I wonder if the people designing all of these touch screen avionics has ever flown before. If so it must have been dead calm out.
 
The UI did look clunky, I must admit. Still, having a path to a new radio with minimal installation cost is a good thing.
 
Yes, I would almost be interested in the KX-155 slide in replacement. For now I'll just use my newer kx-155.
 
I just had my old ks-165s refurbished -- slow warmup missing intermittant segments. Turned out the IC that controls the indicator on the old ones is in a socket which gets corroded. Solution.. pull the socket and solder direct to the board. In my case problem solved. There is a gentleman that works at Bevan that has worked on 155/165 forever and has it together on these units. Serious repair and capacitor replacements $900 tune up on the other $300. Both are clear and as new now. I looked at it like a 500 hour Mag overhaul ... just needed a bit of attention. They know the modes of failure and will tell you if you need new unobtainium plasma displays.
https://www.bevanrabell.com/avionics-bench-repair/


Fyi you can get display lenses on ebay for a few bucks that clears up the clapped out lenses as well. The grey ones look fantastic.
http://www.ebay.com/itm/like/261723632517?lpid=82&chn=ps&ul_noapp=true
 
Agree on the work from Bevan. Great/like new results on my KX165.
 
I would do as little as possible right now. Unless you want to spend $20,000 for a Garmin 650 and ADS-B out I'd replace whatever you have. You can do that yourself by sliding out the old and installing the "used". Most King radios can be bought for $1500 any more. Hopefully in a few years, the FAA will allow some "cheaper" radios and you can upgrade.
 
The one on the video is a mock-up. You can tell by the holes around the knobs it's unfinished. I will hang with my KX-155 for awhile, but may buy an MX-155 to try out. If I like it, I can sell the KX-155 to defray the cost or keep as a spare,. It's my number 2 radio anyway. Bendix-King continues to abandon their GA customers at every turn. No wonder the guys that started Garmin jumped ship from there. No they practically OWN GA.
 
weirdjim said:
I don't understand this comment. Would you elaborate?
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I'm just going by what I've been told by other "non-experts" so take that for what it's worth. But I've been told that with the acceptance of non-certified instruments, there will eventually be more "affordable" radios coming out. I have no first hand knowledge of anything in the works but it makes sense to me that someone would be working on a GPS that doesn't cost $16,000 for GA.
 
lancie00 said:
I'm just going by what I've been told by other "non-experts" so take that for what it's worth. But I've been told that with the acceptance of non-certified instruments, there will eventually be more "affordable" radios coming out. I have no first hand knowledge of anything in the works but it makes sense to me that someone would be working on a GPS that doesn't cost $16,000 for GA.
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They are certified by the STC. Its not an experimental G5 being installed in a certificated aircraft.

Homebuilders have been buying those same "$16,000" GPS navigators as the certified market, no one is selling an IFR capable unapproved GPS for panel mounting. Sentiment reeks of dreams that will never come true IMHO.
 
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There is no such thing as an unapproved IFR GPS. All IFR approved gps's must meet the tso, hence the big cost. Want cheaper IFR gps's talk to big brother. Good luck.

Bob
 
lancie00 said:
I'm just going by what I've been told by other "non-experts" so take that for what it's worth. But I've been told that with the acceptance of non-certified instruments, there will eventually be more "affordable" radios coming out. I have no first hand knowledge of anything in the works but it makes sense to me that someone would be working on a GPS that doesn't cost $16,000 for GA.
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I would ask anybody that has a cite to a regulation that requires ANY instrument or ANY radio on a part 91 general aviation aircraft to **be** TSOd or STCd. Note the emphasis on "be". There are a few (not many) that require that they MEET the TSO specifications, but none that I can find that require it to BE TSOd. As for STC, how many tens of thousands Escort 110s, Kings, Narcos, and dozens of other manufacturers who sell radios and instruments that have neither TSO nor STC? I happen to be one of them, and yes, I researched the regs before I started this company nearly 50 years ago.

If I never again see the word "certified" (which is a meaningless term to start with) regarding equipment (and pilots)) I'd be greatly pleased. Certified is a Post Office term.

Jim
 
Most manufacturers want to be able to sell their products worldwide... EASA, CASA, ANAC, CAA, TCCA, ....... https://en.wikipedia.org/wiki/List_of_civil_aviation_authorities

Some of those aviation authorities won't even accept approved data from the authority of the state-of-design unless it is from the airplane manufacturer. Example, India will not accept FAA approved data for an Indian registered Learjet unless it is Learjet OEM data.
 
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