Weak transmit - radio problem? Bad ANR batteries?

S

samiamPA

Pre-takeoff checklist
Joined
Mar 23, 2020
Messages
183
Display Name
Display name:
samiamPA
I was unable to clearly communicate with approach today. I was less than 20 miles from the station at about 6500 feet. They could hear my initial call, but could not clearly hear my request for FF that followed. This is not the first time this has happened. It seems like at 10+ miles out, transmission becomes spotty.

Does this sound like a bad radio or some other problem? The antenna wire was replaced within the last few years. I did notice the ANR batteries were flashing red when I got home but I didn't think that would cause this problem.

Equipment is a C-150 with a MX-300 and crummy sigtronics intercom. I'm looking for an excuse to upgrade it.
 
If, by "ANR", you mean "active noise reduction" in your headset, the answer is no. That is a function of your headset only, and would only mean you hear less clearly, not the controller.
 
Joe_B1 said:
Check your antenna connections.
Click to expand...
... including the screws holding the antenna to the airframe. Be sure that there is a lockwasher between each internal nut to get a good "bite" of the screw into the skin of the aircraft (makes sure that the skin acts as a ground plane for the antenna above.)
jw
 
Stewartb said:
Check the connection of your PTT switch.
Click to expand...
Just because I like to learn more than I know, what does the PTT switch have to do with a weak signal report?
 
samiamPA said:
I was unable to clearly communicate with approach today. I was less than 20 miles from the station at about 6500 feet. They could hear my initial call, but could not clearly hear my request for FF that followed. This is not the first time this has happened. It seems like at 10+ miles out, transmission becomes spotty.

Does this sound like a bad radio or some other problem? The antenna wire was replaced within the last few years. I did notice the ANR batteries were flashing red when I got home but I didn't think that would cause this problem.

Equipment is a C-150 with a MX-300 and crummy sigtronics intercom. I'm looking for an excuse to upgrade it.
Click to expand...
Put in a GTR-200 (VFR and have a good AP/IA) or certified GTR-225. It has a built in intercom (ditch the sigtronics too), can monitor 2 freq at once, has frequency memory storage, quick emergency transmit, etc. It was great addition to my VFR C150 and not too hard to install, plus we got to rip out a lot of old wiring and put the mic and headset plugs where we wanted them to reduce clutter.
 
Agree with recommendation to check antenna. It is easier to receive through a poor antenna than get power out of one. If you have a SWR meter, check the reading during transmit. If it is high, you may have a poor antenna or cable to antenna.

I had a poor transmission range - less than a mile - but I could hear ATC from many miles away. The SWR was high. Turned out the cable to my antenna was poorly secured, and bounced in turbulence enough times to break wire strands in the cable right at the connector to the antenna.
 
Make sure the mic is close to your lips, like touching.
 
When I was having the same issue it was the antenna. But I went through a couple of headsets before I replaced the antenna and coax. Now I can easily get 60 miles or better.
 
Matthew Rogers said:
Put in a GTR-200 (VFR and have a good AP/IA) or certified GTR-225. It has a built in intercom (ditch the sigtronics too), can monitor 2 freq at once, has frequency memory storage, quick emergency transmit, etc. It was great addition to my VFR C150 and not too hard to install, plus we got to rip out a lot of old wiring and put the mic and headset plugs where we wanted them to reduce clutter.
Click to expand...
Too much money to solve a simple problem ... and it MAY not fix the problem.
jw
 
jim73CQ said:
Too much money to solve a simple problem ... and it MAY not fix the problem.
jw
Click to expand...
But he said he was looking for an excuse to upgrade. This way, you just rip out all the old stuff and replace the wiring and coax and start with zero unknowns. Not to hard to run a few wires for a single radio.
 
Matthew Rogers said:
But he said he was looking for an excuse to upgrade. This way, you just rip out all the old stuff and replace the wiring and coax and start with zero unknowns. Not to hard to run a few wires for a single radio.
Click to expand...
And it STILL may not solve the problem. Why don't you understand that?

And it is "too hard', not "to hard. i find that people who aren't attentive to detail don't know what they are talking about either.

JW
 
Last edited:
jim73CQ said:
And it STILL may not solve the problem. Why don't you understand that?

And it is "too hard', not "to hard. i find that people who aren't attentive to detail don't know what they are talking about either.

JW
Click to expand...
Don’t be so patronizing. A single missing “o” caused by the ubiquitous automated spell check or a slip of the finger. I’ll remember to jump all over you if you ever make a single mistake, pops.

How can a brand new install on a single piece of equipment that functions independently and does not integrate with any existing equipment, with brand new wires (and a new antenna if needed), and checked during install, not solve the problem? Tell me how that works? Install new radio, radio works, throw out old stuff.

And again, the OP is looking to get a new radio.....why not recommend that he get a new radio instead of messing around with a potentially crapped out old radio? That is also part of his question.

I just installed one of these in the same airframe with no prior experience after my Narco crapped out in a similar manner and everything is fine and dandy.
 
I haven't seen what headset he has, but a lot of them have crap mikes to begin with and could have failed. It's a long shot, but it's an easy test, just buy or borrow a different unit and try it out. It's not going to be the batteries in most units as the amplifier for the mic is powered by the bias in the airplane mic circuit (this is how the thing also determines when the plane is running so it can go into battery save when you forget to turn it off). One notable exception is my Tangos which won't work in cordless mode without power to both ends. They do have this emergency cord (stored coiled up in the panel end of the thing) that you can plug in to allow it to work if you lose the batteries completely.
 
Matthew Rogers said:
Don’t be so patronizing. A single missing “o” caused by the ubiquitous automated spell check or a slip of the finger. I’ll remember to jump all over you if you ever make a single mistake, pops.

Helpee selfee, kiddo.

How can a brand new install on a single piece of equipment that functions independently and does not integrate with any existing equipment, with brand new wires (and a new antenna if needed), and checked during install, not solve the problem? Tell me how that works? Install new radio, radio works, throw out old stuff.

"single piece of equipment" does not include wires, antenna, or cable (although most of us in the biz use the abbrvtn "coax"). Each one of those is a link in the system. What you are proposing is what most novices do ... start replacing stuff until you hit the one that is causing the problem in the first place. Of course I started troubleshooting avionics when I was 14 and have done aircraft radio all my life up to date, so what the hell do I know?.

And again, the OP is looking to get a new radio.....why not recommend that he get a new radio instead of messing around with a potentially crapped out old radio? That is also part of his question.

And again, the OP is NOT looking to get a new radio. The grammar of the sentence using "it", refers to the immediate antecedent, which in this instance is his crappy intercom. Last I looked most decent intercoms were 10 to 25% the cost of a new radio. The MX500 is a perfectly good VFR radio, and considering the airframe it is going into, makes a pretty good match.

I just installed one of these in the same airframe with no prior experience after my Narco crapped out in a similar manner and everything is fine and dandy.
Click to expand...

Even a blind pig picks up an acorn every now and again. To be perfectly picky, you did not use the same airframe. Type? Perhaps. Model? Perhaps, but if you used the same airframe he's already GOT a new radio.

jw
 
jim73CQ said:
Even a blind pig picks up an acorn every now and again. To be perfectly picky, you did not use the same airframe. Type? Perhaps. Model? Perhaps, but if you used the same airframe he's already GOT a new radio.

jw
Click to expand...
Give it up already. You aren't helping anyone. You just want to stroke your ego and prove that you are god's gift to the world. The OP does not care if you are the grammar police. And stop with the personal attacks, so far you have said that I was as blind as a pig and that I don't know that I am talking about.

Why waste everyone's time as opposed to offering constructive feedback? Mods, ban us both if you need to, what do I care if I am going to get jumped on for a single missing letter, but this is so counter productive to the OP.
 
The original advice was to test the system components (radio, coax, antenna) separately as opposed to throwing parts at the problem to see which one sticks. If that ain't constructive, I humbly apologize.
jw
 
jim73CQ said:
The original advice was to test the system components (radio, coax, antenna) separately as opposed to throwing parts at the problem to see which one sticks. If that ain't constructive, I humbly apologize.
jw
Click to expand...
That part was, until you started going off on others with different suggestions (or missing letters).

Newsflash, there are different opinions in the world, and pointing out other peoples' non-critical mistakes and saying they don't know anything gets everyone precisely nowher. (E left off for emphasis!!!)
 
samiamPA said:
I was unable to clearly communicate with approach today. I was less than 20 miles from the station at about 6500 feet. They could hear my initial call, but could not clearly hear my request for FF that followed. This is not the first time this has happened. It seems like at 10+ miles out, transmission becomes spotty.

Does this sound like a bad radio or some other problem? The antenna wire was replaced within the last few years
Click to expand...

If you want advice on how to solve the immediate problem, please let me know. What you choose to do or not to do about the radio and intercom is up to you.

jw
 
Ok, hopefully this little grammar feud is over, can we get back to the subject of the OP now?
 
Joe_B1 said:
Ok, hopefully this little grammar feud is over, can we get back to the subject of the OP now?
Click to expand...
Oh, sure, np, that's where we started from, absent distractors. We've got three for sure. perhaps five or six possible problems. In addition, the OP might not have the technical expertise to deal with this him/herself. I'm willing to talk him through this if it takes the rest of the year. I think we can probably eliminate three or four of the problems without a lot of difficulty, but the OP has to want to work on SOLVING the problem, as opposed to using a silver hook to go fishing.
jw
 
FORANE said:
OMG man, that second comma has to be a semicolon!
Click to expand...
Actually, if the subsequent clause bears directly on the precedent clause, the punctuation can be either a comma OR a semicolon. (Jim, running and ducking under a cloud of errant punctuation.)

That is according to my MA-English partner who I have to sleep with tonight, so PLEASE don't start a fight between us. It is often enough between 75+ that we get "together" and tonight could be THE NIGHT !!! :rolleyes:
 
Last edited:
For anyone who is interested in how this actually turned out instead of arguing over grammar, I found the solution today.

It turns out: The nav radio volume being up slightly in this radio causes a static filled transmission that is very weak and difficult to hear.

I read through the logbooks and found an entry from one year ago (previous owner) that was having the same issue. The shop checked all connections and wiring and found it to be good, and made a note that the nav volume needed to be turned down. It was not even making any perceptible noise but it was enough to interfere with my transmission. Volume down, problem solved. What a quirky old unit.
 
That's very strange but glad you found the trouble. Thanks for the follow up.
 
jim73CQ said:
We've got three for sure. perhaps five or six possible problems.
Click to expand...
Oh no. A poorly misplaced period. Looks like we are all human since
jim73CQ said:
i find that people who aren't attentive to detail don't know what they are talking about either.
Click to expand...
I never even picked up that you never capitalized the “I” in this attack. I demand an apology.

But, to the point, looks like the radio is on its way out, so I stand by my recommendation to replace it with a new inexpensive GTR-200/225. It is the type of failure that will come back from time to time at the worst moment when you accidentally bump that volume knob. And these old radios don’t just fix themselves over time.

My old Narco was having random transmission issues for a while and I had a partial power loss emergency 10 miles out from a towered airport. Got just enough communication for the tower to roll the truck and clear the area, but it would not have been nice if we went down early and could not tell them where or when. The radio finally crapped out a year later failing completely to transmit, luckily just on a day of pattern work at the home drome.

There is not much worth upgrading in a C150, but these nice new radios and a set of shoulder harnesses make my C150 a lot nicer.
 
FORANE said:
Agree with recommendation to check antenna. It is easier to receive through a poor antenna than get power out of one. If you have a SWR meter, check the reading during transmit. If it is high, you may have a poor antenna or cable to antenna.

I had a poor transmission range - less than a mile - but I could hear ATC from many miles away. The SWR was high. Turned out the cable to my antenna was poorly secured, and bounced in turbulence enough times to break wire strands in the cable right at the connector to the antenna.
Click to expand...

Correct. Transmission requires significantly more power than reception.
 
You must log in or register to reply here.
Back
Top