Hello,

I have a share in a 1959 c-182b. Because the airplane is based at merrill/hood, to me reliable radios are important.

The airplane came with a kx-170a that had been deactivated because it lacks .125 spacing or just doesn't work. The 2nd radio is a kx-155 which works ok. The kx-170a has a CDI for its nav radio which also is inop.

We want a cheap and reliable replacement for the kx-170a. Is the kx-170b a good choice? The local shop has one for $600 and also a kx-175 that is TSO'd for $800. My partners kind of want a craigslist ky-195 which is comm only for $200. Any other recommendations? All of the radios I mentioned. Weigh within 1 lb of the original kx-170a so no weight and balance adjustment would be required, afaik.

The only problem I notice is that when I fly abeam some radio towers in eagle river I hear country music on every frequency through the kx-155. I can still hear asos/ctaf, there is just loud staticy music in the background.

Is changing these radios out something a pilot with zero maintenance know how could attempt? It sounds like the 3/32 Allen wrench screw on the front is all that holds the radio in, but idk. It's my understanding that this sort of work is legal under the regs for pilots to do. Any comments welcome.

I can’t help you with any specifics, but I can pass on some generalizations.

Good quality radios are expensive, period.

Poor quality radios are a waste of money, always.

“Cheap and reliable” is not often used to describe aircraft radios.

Radio and antenna instillation is significantly more complicated than it appears at first glance, and testing the instillation requires specialized skills and equipment.

A poor quality radio or poor instillation is more dangerous than no radio at all, because you think you’re communicating, but you’re not. I had a near head on collision on a runway because a pilot thought they were communicating, but they were only talking to themselves.

I guess in summary I’d recommend spending enough to have a quality radio installed by a competent technician, or do without.

Good luck!

Thank you Hammer. Your comments about having it installed by someone competent mirror my desires as well. Ideally someone who would let me watch and learn. I was somewhat surprised to be told by the mechanic at the local shop selling the radios that he thought I should just install them myself; he seemed disinclined to take on the work, but indicated he thought it would take about 2 minutes. Unscrewing it from the panel is one thing, but I have no idea what I would find on the back of the inop KX-170a that's in the panel now in terms of wiring and how much slack I would have to work with.

I am personally leaning toward the used KX-170b that has been refurbished by the local avionics shop. They're asking $600. I am not the sole owner of the airplane, however so I cannot make the choice unilaterally. I have researched the benefit of the KX-175 being TSO'd but it doesn't seem like much (if any) benefit for the extra $200.

https://cessnaowner.org/tkm-avionics/ is my main source of information about the radios.

Also, spoke with another shop today and he said just to steer clear of all the older KX-170 series radios because they're all too old. Granted, it was an avionics shop selling $2k garmin radios.

I am not opposed to spending a few thousand if that's what it takes to have a reliable second radio. A $2k second radio would be an expense approaching 5% of the entire airplane's value without adding much value unfortunately.

So if your replacement radio uses the same tray and connections as the old, non-functioning radio, AND the instillation of the non-functioning radio was done right to begin with and hasn't deteriorated over time, then changing radios is as simple as pulling one out and sliding the next one in.

But it's pretty...er...optimistic...to believe that the old power supply, coax and antenna are still in good order, even if the radios are interchangeable. That you're picking up music on the functioning radio is an indication that there is a issue with how that radio is installed, and since it's the one that works, what are the chances that the other radio instillation is up to spec? That you can radio-check a guy on the other side of the ramp doesn't really tell you much about how the radio is working in the flight environment.

I'm as cheap as anyone, and as handy as many if not most non-mechanic airplane owners, and I've learned that some things are just worth paying the professionals to do once and do right. Radios fall squarely into that category. (Oh...pick the right radio shop...they aren't all five-star establishments from what I've seen.)

Or, you might get lucky with a two-minute slide in of a used radio... It has probably happened before, once or twice. Testing it in the flight environment without actually relying on it for important comms might show it to be viable.

And FWIW, I got certified commercial-instrument with a single comm radio. It wasn't as easy as with two radios, but it's possible. One radio is really all you need. If your partners don't want to pony up the money to do a second radio right, you might suggest putting it off until they do. No point in putting 30% of the money for a working solution into a non-working solution and being worse off than when you started.

If it’s a tray-type and the connectors and wiring diagrams are compatible, it really is as simple as loosening a hold down clamp with an Allen key (through a hole in the front of the radio), sliding the old radio out, siding the new radio in, and then tightening the hold down clamp in the new radio (through a hole in the front of the radio) and you’re done.

But I second all of Hammer’s comments. Older, used stuff can be had at lower prices, but they’re largely unsupported by the manufacturers any longer.

I’m happy with my Icom A200 though. I think they made a TSO version.

Narwhal747 wrote:Also, spoke with another shop today and he said just to steer clear of all the older KX-170 series radios because they're all too old. Granted, it was an avionics shop selling $2k garmin radios.

I'd try to find out if any of the “newer” KX radios share that tray and connections. If they do then buy a certified radio from a reputable dealer who will stand behind the purchase and see if it will plug’n play. If it doesn’t and you have to redo the install, at least you have a radio that fits the rack and panel, which should be a savings over installing a radio that doesn’t fit the rack and hole you already have.

There are just so many aspects of radio instillation that can cause problems...the last thing you want to add to it is a questionable radio. In many instillations the radio is the cheap part.

Thanks for the continued info, we will probably fly through the winter on the one radio and assess at the next annual. As Hammer said, one radio is fine, the airplane has not had a static/altimeter check in some years so it is not IFR legal anyhow, not that much IFR is possible during winter without risking ice. The KX-155 nav radio does pass a VOT check. Partners seem more interested in some kind of ADS-B out+in solution for traffic awareness using an ipad than anything else in terms of avionics.

Since we are based out of hood/merrill it would just be nice to have a backup, maybe handheld is the way to go. The only time I get the interference on the working KX-155 is when I fly within a mile or so of some radio towers in eagle river that are on top of a mountain just east of the glenn highway (above or approx same elevation as aircraft)...goes away once I get away from the towers. Then again, I fly other aircraft in that area without such an issue so it is indicative of a shielding/wiring problem of some kind. Merrill ATC has not yet complained about the quality of my transmissions nor have I had any difficulty understanding them.

Narwhal747 wrote:I am personally leaning toward the used KX-170b that has been refurbished by the local avionics shop. They're asking $600.

Well, this is just one guy's experience, but...

My Citabria has a KX-170b with a KI-201C VOR/LOC indicator. When I first got the plane, the radio had not been used for about 12 years (guy operated off a pasture on his property. The COM side seemed to work OK, but the NAV side was totally dead. My local avionics shop guy offered me a "working when removed" KX-170b for $100 – to sweeten the pot when I was doing the ADS-B installation. However, he recommended that I replace the "boat anchor" radio with a new solid-state Garmin or ICOM (he personally preferred the Garmin). I foolishly opted for the $100 KX-170b to "save some money"...

Since then, I've gone through 3 more of the "working when removed" (each was bench tested and passed all tests, by the way – the last one while I watched!). Every single one of them has had issues. This is the only radio installed in the airplane, and each of the five radios failed within 5-10 hours of being installed: squelch failure on one, transmitter failure on two others, receiver failure on one, and one that simply would not stay plugged in – keeps working itself loose from the connector in the back. One of those COM failures happened just after I entered the DFW Class B airspace (had just received my clearance and acknowledged it when the transmitter quit working).

At this point, I've wasted so much time and effort (not to mention the laundry bill after the Bravo incident) that I REALLY wish I had followed my avionics guy's advice and installed the Garmin radio.

I now keep my handheld radio (Sporty's SP-400) attached to a RAM mount one one of the tubes next to the windshield every time I go flying. I've had to use it about 7-8 times in flight. Just as soon as the avionics shop works its way through their ADS-B installation backlog, I will have them replace the KX-170b with one that does more than just occupy the hole in the panel...

If I were doing it again, I would NOT spend the $100 to fix the NAV radio, and just save my money towards a modern, solid-state radio...

Good luck!

Thank you for sharing Jim, I will certainly take that into consideration and think really hard about spending money for a decent modern radio, or perhaps just stick with the one good kx-155.

Speaking of hearing the radio station when just N of Eagle River....that seems to have developed recently. Either several (many?) plane radios have developed the same default, or perhaps something is different in the transmission coming from those antennae.

I did not pick it up in recent years, but within the last year it has been coming across to my headset.

I have a KX-155 as well

Sean

Not sure what my comments add to this, other than a FWIW sort of thing. When I bought my airplane, it had a pair of Cessna 360 channel navcoms, which were illegal. I replaced both with a pair of Narco slip-ins, as I'd had lots of good experience with Narcos over many years. Of course, Narco bellied up, so I ended up with a pair of orphan radios, but they worked fine, until the nav side of one of them started getting wonky. The avionics shop in Alamosa repaired it, to the tune of about $600.

Then my VOR tracking on both radios really diminished. An avionics shop which is now out of business wanted to replace the "feeler" antenna to the tune of several hundred dollars. My IA said "let me look at it". He unscrewed each feeler, sprayed some contact cleaner on both sides, reinstalled them, and they've been fine ever since--good VOR reception on both radios.

Along the way, I had a new Garmin 430W installed, pretty much the last of the new ones that Garmin sold. It's been a great radio itself, but when it was installed, the avionics shop didn't replace the antennas or cabling for the comm side or the nav side, just added the GPS antenna.

Now here's where the complications arise, and they're just examples of what can happen when relatively simple things start interfering with good communications and navigation reception (you already saw what happens when some corrosion crept in on my nav antenna).

I had intermittent transmitter problems. It sounded fine to me through the headset, but often enough, someone or ATC would say all they were hearing was a carrier. That turned out to be a loose nut behind the mic jack for the passenger side headset--simple fix, but hard to nail down, since most of my flying is solo--had I had a passenger who couldn't trigger the intercom, maybe it would have been easier.

Then, my distance transmitting capability shortened considerably. I first noticed this when Denver Approach handed me off to Colorado Springs Approach, and although I was already over the hill just north of KCOS, ATC couldn't hear me.

Sometime earlier, when I had my ADS-B Out accomplished with a new KT74 transponder, that avionics shop (not the one that installed the 430W) had recommended that I should replace the OEM antennas installed in 1962. I had just spent a bunch, so I put it off. But when I started having the distance transmitting problems, it was time to do something. So I arranged to have them install new quality antennas. In the process, they discovered that the coax from the panel to the antennas was badly cracked in several places, largely because the Cessna installers had bent it too much, and over the years, it just gave way. So they ran new coax to the new antennas--total solution.

But none of that was cheap. It sounds to me as if your partners don't understand the cost of airplane ownership. Yeah, there are a few things that can be done to maintain airplanes inexpensively, but most of the time, it's either spend the money now or spend it later. Like when my IA told me that I needed a new exhaust system, he said that he could repair the old one and it would likely last another year, or he could replace the exhaust system and it would likely last until I quit flying in the future. I opted for the new exhaust system.

The old saying is appropriate here: you can buy good oats, or you can buy oats that have already passed through the horse. Your choice, and your money. There will come a time when the choice is spend the money, or mothball the airplane.

Cary

seward wrote:Speaking of hearing the radio station when just N of Eagle River....that seems to have developed recently. Either several (many?) plane radios have developed the same default, or perhaps something is different in the transmission coming from those antennae.

I did not pick it up in recent years, but within the last year it has been coming across to my headset.

I have a KX-155 as well

Sean

Wow, interesting. I fly an R44 helicopter through the Eagle River area periodically as well; it has no issues with the interference, granted it has a Garmin 430W. I'm glad it's not just our airplane though.

Basically, the avionics dilemma on our airplane is that at least 1/3 of its value is tied up in the O-470 that has 350 hrs SMOH. I have a feeling if we started messing around with radios would be looking at $5000 pretty fast. I think we are going to be content with the one working kx155. If it fails then we use a handheld and stay out of the ANC area. 90% of the airplanes we looked at buying up here had one radio anyway, some only a handheld.

I have replaced a KX170B when it was not working right. I replaced it with another KX170B. I don't buy 'working when removed' stuff though. I bought one with certified by an avionics shop with an 8130. Costs more, but unlike the other story, mine has worked well for the 6 years since I installed it.

The KX175B is one of the best most bullet proof radios ever made, and it's a slide in replacement- you're DONE. Get the avionics guy to let you test fly it. I am pretty sure the rack has to be changed for the 195 com/com which will be a PITA. I had dual 175's in my 180 for 20 years WITH ZERO MX on them... and bought them based on my Avionic shop pal recommendation over the 155's.
Just be gentle with the tuning switch (esp cold wx) they are getting rarer.

My experience with handhelds in the cockpit is not good...very short range and usually VERY hard to hear on both ends. They are just about worthless if you have a high workload in the cockpit. If you want a fun experiment, try using a handheld while navigating airspace in a bit of wind...harder than you'd think.

A couple things that will make them much more usable, even for emergencies:

Mount a external antenna and run coax to the handheld. That will tripple the range and clarity of your transmissions, and make incoming transmission much louder and clearer.

Select a handheld with bluetooth if you have bluetooth headsets, or wire the handheld directly into the intercom if you don't. You'll actually be able to hear the radio without taking your headset off and pressing it against your ear, which is a serious pain in turbulence or while IFR-ish.

Figure out a way to mount the radio so you can see it and use it without having to hold it in your hand. If you have to use the handheld PTT button and microphone, make sure you can lean in and talk on the radio without much fuss or bother.

Buy a GOOD radio. If the $35 Chinese radios that have been on the market for a decade actually worked well, nobody would fork out ten or fifteen times that much for a Yaesu or Icom or XXX brand radio. The difference is in the quality of the transmissions and the reliability of the unit. You get what you pay for.

All in all, handhelds are a pretty marginal solution in the cockpit. I often talk on non-aviation radios while flying, and I'm always amazed by how much harder it is to communicate compared to using the aircraft radio hooked into the headset with a PTT button on the yoke.

seward wrote:Speaking of hearing the radio station when just N of Eagle River....that seems to have developed recently. Either several (many?) plane radios have developed the same default, or perhaps something is different in the transmission coming from those antennae.

I did not pick it up in recent years, but within the last year it has been coming across to my headset.

I have a KX-155 as well

Sean

My airplane picks up this darn station every time. It has a KX-155. It does it every time i fly over Eagle River for the last couple years. My old 145 did the same thing many years ago. Every airplane i fly with a newer radio NEVER picks up that station. I think its an old radio thing.

Hammer wrote:Mount a external antenna and run coax to the handheld. That will tripple the range and clarity of your transmissions, and make incoming transmission much louder and clearer.

100% agree with this statement. That's how my airplane is equipped, and I've talked to ground stations 30+ nm away with no problem.

Hammer wrote:Figure out a way to mount the radio so you can see it and use it without having to hold it in your hand. If you have to use the handheld PTT button and microphone, make sure you can lean in and talk on the radio without much fuss or bother.

Again, 100% agree. I use a RAM mount (the "claw" type) on one of the tubes near the panel, plug in my headset, and use a PTT switch attached to the stick with velcro.

Hammer wrote:Buy a GOOD radio.

Again, good advice. After playing with various ICOM, Yaesu, and the Sporty's SP-400, I bought the SP-400. Not only does it get excellent reviews from other pilots, it was the only one I could easily use without the manual. I figure that to be fairly important, since the times you'll most likely need it most are going to be "high-stress" situations, and you don't want to be digging around for a manual at those times...

Hammer wrote:All in all, handhelds are a pretty marginal solution in the cockpit. I often talk on non-aviation radios while flying, and I'm always amazed by how much harder it is to communicate compared to using the aircraft radio hooked into the headset with a PTT button on the yoke.

Here I would differ with Hammer a bit. The SP-400 is definitely less powerful than the KX-170B, but I have been pleasantly surprised at how well it works, and how good it sounds in the cockpit. Of course, I'm using it with the headset plugged into their optional adapter, but that's a pretty inexpensive upgrade that is a good idea for a whole bunch of reasons...

Maybe it is an "old radio" thing. I did not pick up the station several years ago, but do now. Likely my radio is starting to fail. sigh. its only money

Sean

Seems odd that all these KX-155's would be failing at the same time? It's too much of a coincidence that we're all getting the same problem by those radio towers! It's either some kind of problem with the design of the radio or the transmitters on those towers are doing something unusual! Really only a problem within a 2 or 3 NM radius of those towers, for me.

The handheld, if we got one would only be an emergency backup. I certainly wouldn't be trying to use a handheld on a regular basis. Unfortunately at the moment there is a long list of maintenance to-do items on the airplane (doors won't lock, primer pushing air for the first 5 or 6 strokes, maybe a small fuel leak on the bottom of the cowl, need a corrosion treatment, some play in the h-stab).

A handheld isn’t a bad thing to have in your emergency vest in any case...I like the option of using AA batteries (lithium) because of their long shelf life and low temperature stability, though AA powered radios are getting hard to find. If it has a rechargeable battery remember to pull it out and charge it every couple months at least.

Regardless of the battery type, block the battery contacts with a piece of plastic flagging so it can’t power up accidentally.

Keep it in a ziplock if it isn’t submersible, and consider upgrading the antenna. I like Smiley Antennas. I remove the antenna and rubber band it to the radio to make it more compact in the vest.