Radio help please - I have no idea

[McMooney]

so sunday, an absolutely perfect day for flying in Houston, I randomly decide to fly to Lake Charles, LA.

take off, everything is great, get to altitude no problems, descend to approx. 3500, radios are nothing but static.

Mind you I'm on flight following,  ATC was NONE TO THRILLED.

fly for a while, static goes away, switch to lake Charles approach perfect.

On the way back, everything is initially perfect.  absolutely clear thru the climb to 8500 and cruise.

I switch to Houston approach (132.375 ) or something, static and drop outs.  ATC gives me a what for then drops me from flight following.

I need to get this fixed, its more than a little disconcerting when the radios just randomly decide to work. 

any ideas?  

 

really hate the idea of spending a bathtub of cash having someone experiment looking for the issue.

 

I'm not sure what to do, or even how to proceed.

[N201MKTurbo]

Both radios?

Did you hear static or did they? Or both?

 

Edited May 8, 2018 by N201MKTurbo

[Skates97]

Also, what radio do you have and if it was both radios what models? 

[Warren]

I had intermittent issues with my radios. When I pushed on the radio or the audio panel it would suddenly improve. Eventually I fixed it by reseating the radios and the audio panel as well as fixing an antenna connection where the shield was completely broken at the connector on the radio tray.  The bad connection was on the back of my KX 165 (I guess 30 years of upgrades and manipulation finally stressed the connection too much).  Replaced the connector and I have had clear communications since. 

[McMooney]

mx-170b and kx-170b, the kx-170b ( com2 ) seems better than the mx-170b com1

 

no only i hear static,  atc can't here me at all when it happens

[EricJ]

I had some similar behavior for a while, and it may have been multiple issues.   I did find a USB power adapter that was going a little crazy once in a while, so replacing that helped.   I also swapped out my ancient KMA20 audio panel for one I got on ebay for cheap, and that helped, too.   I think replacing the 40-year-old KMA20 with another forty-year-old KMA20 was a partial fix, because although things did get better, it didn't completely solve the problem.

I nursed things along long enough that it lasted until the airplane went in for new avionics.   In my case I suspect the second audio panel was better, but still had it's own issues.   YMMV.

 

[Jerry 5TJ]

Probably  something common to both radios:

• audio panel
• intercom
• plane’s generator/voltage regulator 
• Headset or mic

[carusoam]

8 hours ago, McMooney said:

I ...fly to...

radios are nothing but static...

...on flight following,  ATC was NONE TO THRILLED.

 

Houston approach, static and drop outs. 

ATC ...drops me from flight following.

 

I need to get this fixed, its more than a little disconcerting when the radios just randomly decide to work. 

any ideas?  

 

really hate the idea of spending a bathtub of cash having someone experiment looking for the issue.

 

I'm not sure what to do, or even how to proceed.

McMooney,

I cut out all the static in your post....  

focussed on what the challenge is...

Tried to get a feel for what you need...

Knowing what you asked...

 

1) You have radio technology from the 70s.

2) There is something wrong with your radios/installation.

3) You use your radios to fly.

4) Time to get a new to you radio with fresh install...

 

recomendation...

go see the man that sells used digital GPS/Nav/com boxes.

get one.

have it installed.

Celebrate the ability to fly somewhere randomly, talking clearly to every ATC station as you go...

Expect looking forward to spending money on new wire, antenna, and connectors...

Also Expect that you can waste more time, money, on other 70s stuff like platform shoes and wide ties...

The KX170B Both made BK and broke BK... They made a good radio once... and held on to it for way too long.

Feel free to take down the mirror ball and put away the disco records.

 

Or, start at one end, proceed to the other... clean every connection from antenna to radio to ground... depends on your skills.

oxidation is the enemy...

 

Or, start in the middle where BK went from tube radios to digital technology.   KX155 or KX165???...

 

 

 

PP thoughts only... not a radio guy...

Best regards,

-a-

[neilpilot]

3 hours ago, Jerry 5TJ said:

Probably  something common to both radios:

• audio panel
• intercom
• plane’s generator/voltage regulator 
• Headset or mic

Agree.  One other commonality to consider is the noise reduction capacitor (if you have one).  We recently noticed increased static, and the capacitor tested bad.  A replacement cured our issue.  I bought 2, so have an extra if anyone needs one.

[Bob_Belville]

It's not clear to me from the OP but it is possible that the problem is limited to a single frequency. There's a sector in Western VA where I get static on my fancy GTN750. If the static occurs when you're assigned a new freq and the other freqs was okay you might ask ATC if they have another freq. 

[1964-M20E]

Flying home form Indy Sunday in an area around McComb Mississippi the squelch kept opening up on a frequency for Houston Center.  This was on my IFD540.  No other issues so something with that freq in that area.  I have had terrible interference before in certain areas on certain frequencies with other radios.  Avionic guy blamed it on old ELT but I'm not so sure.

this is FM (freaking magic) technology for you.

Go from antenna to radios and tray connectors and make sure everyone is clean and making a good connection.  My NAV 2 sometimes gets really static and a cleaning of the antenna connector on the tray helps.

 

[Marauder]

Another thing to consider is if you made any changes to the plane that could cause the interference. I had one experience where my squelch kept opening because a newly installed JPI 900 was creating the issue. I had another more recent incident where I kept hearing a whine on the pilot headset but nothing on the other jacks. I have isolated it to a piece of equipment that may not be grounded correctly.

And as others have pointed out, sometimes these interferences are unique to an environment or timeframe.

[Jerry 5TJ]

If all else fails, spray some WD-40 through the relief tube.  

Seriously, suggest you take detailed notes on exactly what’s happening:  which radio, which frequency, location, symptoms, aircraft electric power voltage and current, anything notable.  

Locating and fixing intermittent problems is vexing; the tech will need all the help you can offer.  

Another suggestion:  Carry a handheld aviation transceiver & see if the problem extends to it when the panel radios act up.  

PS I had similar problems in my 1965 C model with the Mark 12D and a KX170B it came with. Intermittent radio and audio issues that I tried to track down for several years. Finally I fixed it:  I removed all the Avionics, all the racks, and all associated wiring. Reinstalled a 530W, Icom A210, etc, and PS Engineering Audio panel with all new harnesses and single point grounding.   Problem went away.  

[Marauder]

3 hours ago, Jerry 5TJ said:

If all else fails, spray some WD-40 through the relief tube.  

Seriously, suggest you take detailed notes on exactly what’s happening:  which radio, which frequency, location, symptoms, aircraft electric power voltage and current, anything notable.  

Locating and fixing intermittent problems is vexing; the tech will need all the help you can offer.  

Another suggestion:  Carry a handheld aviation transceiver & see if the problem extends to it when the panel radios act up.  

PS I had similar problems in my 1965 C model with the Mark 12D and a KX170B it came with. Intermittent radio and audio issues that I tried to track down for several years. Finally I fixed it:  I removed all the Avionics, all the racks, and all associated wiring. Reinstalled a 530W, Icom A210, etc, and PS Engineering Audio panel with all new harnesses and single point grounding.   Problem went away.  

Seems you fixed your slow Ovation problem the same way. Replaced it with a turboprop. 

[rpcc]

7 hours ago, neilpilot said:

Agree.  One other commonality to consider is the noise reduction capacitor (if you have one).  We recently noticed increased static, and the capacitor tested bad.  A replacement cured our issue.  I bought 2, so have an extra if anyone needs one.

Will the noise reduction capacitor remove noise from all parts of the electrical system.  I've had problems with noise introduced from my Ipad charger plugged into a cigarette lighter ?  

I would start by turning off all electrical componets other than com one and try that - is there still static?  Turn off com one and then turn on com two - is there still static on the second radio.  That should isolate your issue to something related to the radios and not some other issue.  

If you get there the conversation with your mechanic should be much shorter.

Good luck.

[McMooney]

oh yeah panel pic

[carusoam]

That panel is worthy of a WAAS gps/nav/com!

find @Alan Fox‘s radio emporium to see what he has on the shelf...

 

Story behind  Alan, the Grimm reaper, Sanford, Fox...  He is in the business of placing good misplaced avionics into good homes...

A Garmin 430W would be great... a G430 would be almost as good....

Best regards,

-a-

 

[Jerry 5TJ]

15 hours ago, Marauder said:

Seems you fixed your slow Ovation problem the same way. Replaced it with a turboprop. 

Best Mooney speed mod:  Forget gap seals or cowl upgrades (?), just add a 750 hp PT6A.  

[Yetti]

I have an audio panel and a 170b you could swap out.   Also we're both radios on same or close frequencies?

[drapo]

As Yetti says, if No 2 radio was on the same frequency, or close to it, since it's pretty old technology to use 132.375, that could cause the noise and static as both antennas are too close to one another on our short airplanes... Happened to me, now every time something similar occurs, my first troubleshooting is to power off No 2 radio.

[Yetti]

I believe it is more like the local oscillator of both radios start to interfere with each other.  But that was a bunch of stuff I did not learn, but something to check even if I can't explain it technically.

[EricJ]

16 hours ago, Yetti said:

I believe it is more like the local oscillator of both radios start to interfere with each other.  But that was a bunch of stuff I did not learn, but something to check even if I can't explain it technically.

"Intermodulation distortion." 

 

[Yetti]

always good to have someone around that is smarter than yourself

[carusoam]

Surround yourself with smart friends... 

Go MS!

-a-

[McMooney]

Thanks for all the help, carusoam is probably dead on just need to bite the bullet.
Gonna try flying with one radio this weekend.  CB Forever

looking at installing a Garmin 300xl and new to me audio panel after annual.  

might add a gns-480 if i can find one.

 

Edited May 12, 2018 by McMooney