Van's Air Force
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"Scratchy" radio transmission
- Thread starter meadeduck
- Start date
Antenna ?
Checking the antenna is a good starting point. It should be well grounded and cable connector should be secure.
Can you hear yourself talk while transmitting? If the side-tone is "scratchy", suspect the PTT switches.
Also try turning the intercom off to see if that makes a difference.
Joe Gores
Checking the antenna is a good starting point. It should be well grounded and cable connector should be secure.
Can you hear yourself talk while transmitting? If the side-tone is "scratchy", suspect the PTT switches.
Also try turning the intercom off to see if that makes a difference.
Joe Gores
Another unpleasant thought - -
I had a problem early on, and it turned out being the cable connection at the antenna. The center connector was not crimped well enough. Try moving the cable around at both ends to see if it makes any difference. I could move it and make it change. Not fun to fix, but can be done.
Do both PTT switches give the same results ?
John Bender
I had a problem early on, and it turned out being the cable connection at the antenna. The center connector was not crimped well enough. Try moving the cable around at both ends to see if it makes any difference. I could move it and make it change. Not fun to fix, but can be done.
Do both PTT switches give the same results ?
John Bender
JerryG150
Well Known Member
me too ...
I was landing at KSRQ this morning and Tampa Approach said my transmission was extremely garbled. As I spoke my feedback in my ear was all broken up every second or two. I was fortunate they handed me off to KSRQ tower and they gave me clearance to land on 32 ... and told me to get it fixed immediately. Neadless to say I'll take it to Sarasota Avionics asap and let them know what you guys posted here. Thanks
While in the shop, I'll see if they can adjust or fix my anti-servo tab indicator on my Dynon 180 ... as soon as I make a slight adjustment, up or down, the indicator shows full up ... but the -12 pitches perfectly ... in tiny increments ... fine to fly ... just the indicator is off.
Oh yeh, my 4 year old grandson is trying to win an Ipad2 on Facebook. If any of you RVators have a Facebook account he would and I would appreciate your vote. (Click here to vote) He's the little guy holding up a piece of bacon. You can vote daily thru 10/2 if so inclined. Thanks a lot.
I was landing at KSRQ this morning and Tampa Approach said my transmission was extremely garbled. As I spoke my feedback in my ear was all broken up every second or two. I was fortunate they handed me off to KSRQ tower and they gave me clearance to land on 32 ... and told me to get it fixed immediately. Neadless to say I'll take it to Sarasota Avionics asap and let them know what you guys posted here. Thanks
While in the shop, I'll see if they can adjust or fix my anti-servo tab indicator on my Dynon 180 ... as soon as I make a slight adjustment, up or down, the indicator shows full up ... but the -12 pitches perfectly ... in tiny increments ... fine to fly ... just the indicator is off.
Oh yeh, my 4 year old grandson is trying to win an Ipad2 on Facebook. If any of you RVators have a Facebook account he would and I would appreciate your vote. (Click here to vote) He's the little guy holding up a piece of bacon. You can vote daily thru 10/2 if so inclined. Thanks a lot.
RickWoodall
Well Known Member
Back up comm
A little off topic, but just a suggestion for anyone opertating with just one comm. Carry your backup! I had a total comm failure during a recent flight across country with my son.
Luckily I had my vertex handheld, that comes with earjack plugs (like $200 complete). I grabbed it, snapped my headphones in and it was outstanding. Never had a comm failure before but very glad my handset was within reach, charged and had a headset jack. Turned a big problem into an almost not issue.
Just a suggestion to keep yours within reach and charged for action. Losing a comm when its your only one...not so much fun in controlled air and I was very lucky I didnt have to recall the light signal stuff.
A little off topic, but just a suggestion for anyone opertating with just one comm. Carry your backup! I had a total comm failure during a recent flight across country with my son.
Luckily I had my vertex handheld, that comes with earjack plugs (like $200 complete). I grabbed it, snapped my headphones in and it was outstanding. Never had a comm failure before but very glad my handset was within reach, charged and had a headset jack. Turned a big problem into an almost not issue.
Just a suggestion to keep yours within reach and charged for action. Losing a comm when its your only one...not so much fun in controlled air and I was very lucky I didnt have to recall the light signal stuff.
JerryG150,
Like John Bender asked, "Do both PTT switches give the same results?" Could be bad PTT switch. I replaced both of mine. Watch the little indicator on the SL40. Does it flash on and off? If so, that is another indication that the PTT switch or its wiring is bad. The SL-40 tray connector could also be the problem.
As for the pitch trim indicator, it could be a bad pot inside of the servo. Or it could be a bad connection. I would check the crimps and connectors at the servo.
Joe Gores
Like John Bender asked, "Do both PTT switches give the same results?" Could be bad PTT switch. I replaced both of mine. Watch the little indicator on the SL40. Does it flash on and off? If so, that is another indication that the PTT switch or its wiring is bad. The SL-40 tray connector could also be the problem.
As for the pitch trim indicator, it could be a bad pot inside of the servo. Or it could be a bad connection. I would check the crimps and connectors at the servo.
Joe Gores
If your transmission on ground is ok but in air bad then it leads to power, ground or interference problems.
Suggesting Revs and change in charging circuit might be part of it.
If you still have the problem send me an email at tatlockj@@netspace.net.au (less one @).
Give me all the info and I'll try and steer you towards a fix.
Jim
Suggesting Revs and change in charging circuit might be part of it.
If you still have the problem send me an email at tatlockj@@netspace.net.au (less one @).
Give me all the info and I'll try and steer you towards a fix.
Jim
JerryG150
Well Known Member
radio transmission ...
Once again, I was in the hospital having my second triple bypass surgery when my avionics was installed.
That being said, after spending mucho $'s to have my radio checked out and ELT fixed, I asked ground for a radio check before taking off from Sarasota airport and I was still transmitting intermittently with lots of static.
I taxi'd to the avionics shop again and they checked it out. The technician pushed the radio deeper into the panel and he said it was much better. Then he pushed the transponder deeper into the panel also. Both units were not tightened into the tray. He then got an allen wrench and tightened both units thru the front hole ... radio is much better now.
Once again, I was in the hospital having my second triple bypass surgery when my avionics was installed.
That being said, after spending mucho $'s to have my radio checked out and ELT fixed, I asked ground for a radio check before taking off from Sarasota airport and I was still transmitting intermittently with lots of static.
I taxi'd to the avionics shop again and they checked it out. The technician pushed the radio deeper into the panel and he said it was much better. Then he pushed the transponder deeper into the panel also. Both units were not tightened into the tray.
He then got an allen wrench and tightened both units thru the front hole ... radio is much better now. Scratch radio...
While visiting relatives on the Left Coast, I went to Chino ("Flo's" got the BEST biscuits and red-eye gravy) and was wandering around the airport when I noticed an avionics shop. I stopped in and spoke with one of the techs there and he told me that I needed to reread the manual and do the setup on the radio....which I'm going to do as soon as I get back.
Meade
N612RV (1/2)
While visiting relatives on the Left Coast, I went to Chino ("Flo's" got the BEST biscuits and red-eye gravy) and was wandering around the airport when I noticed an avionics shop. I stopped in and spoke with one of the techs there and he told me that I needed to reread the manual and do the setup on the radio....which I'm going to do as soon as I get back.
Meade
N612RV (1/2)
N941WR
Legacy Member
What type of antenna do you have on the RV-12?
I have a Comant antenna on my -9 and developed a scratchy radio. It turns out that I wasn?t getting a good ground from the antenna to the fuselage.
The solution was to remove one screw at a time, make a few quick turns with a deburring tool (a countersink bit would also work) in the aluminum antenna base, and put the screw back in with a coating of dielectric grease.
There was enough surface corrosion in the screw hole to cause the problem. Symptoms where the same as what you described, good transmission on the ground and planes flying close by but 10 or more miles away was bad news.
I have a Comant antenna on my -9 and developed a scratchy radio. It turns out that I wasn?t getting a good ground from the antenna to the fuselage.
The solution was to remove one screw at a time, make a few quick turns with a deburring tool (a countersink bit would also work) in the aluminum antenna base, and put the screw back in with a coating of dielectric grease.
There was enough surface corrosion in the screw hole to cause the problem. Symptoms where the same as what you described, good transmission on the ground and planes flying close by but 10 or more miles away was bad news.
N941WR
Legacy Member
FYI - It wasn't "rust" but more like oxidation. All I had to do was spin my de-burring tool in the hole about three times is all. The dielectric grease helps make better contact and prevent future oxidation / corrosion.
PS. Remember to do it one screw at a time. That way you don't have to worry about the antenna moving out of position.
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Walt
Well Known Member
It will help to prevent corrosion by keeping moisture out but Dielectric grease is a nonconductive grease. As such, it does not enhance the flow of electrical current. Dielectric grease is, however, often applied to electrical connectors, particularly those containing rubber gaskets, as a means of lubricating and sealing rubber portions of the connector.
It is not recommended to be applied to the actual electrical conductive contacts of the connector because it could interfere with the electrical signals passing through the connector (the screw contact area in this case).
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N941WR
Legacy Member
Ya learn something new every day! Thanks Walt. Still, my transmissions are clear. I wonder if they would improve if I removed the grease?
Walt
Well Known Member
At the contact area the grease was likely pressed out so I doubt you would see any improvement. A better way is to clean the contact area with contact cleaner, install the screws (or connector) and then spray/fill the void with a corrosion preventative compound such as ACF-50.
Grease...
Yeah.. thats what I was wondering about the grease too. Any recommendation on what to apply to prevent oxidation and loss of contact?
So'll just plan to look for oxidation around the screws and make sure the grounding is good.
Any other tests that I can do to see oif the antenna is being ground properly?
Thanks
Yeah.. thats what I was wondering about the grease too. Any recommendation on what to apply to prevent oxidation and loss of contact?
So'll just plan to look for oxidation around the screws and make sure the grounding is good.
Any other tests that I can do to see oif the antenna is being ground properly?
Thanks
JerryG150
Well Known Member
In Tight?
Be sure your radio is in tight. there is a little screw or hex nut on the side (or in the face) to tighten it into the tray. mine was not secured tight to the tray in the panel. after Sarasota Avionics worked for an hour or so with my bad reception it was caused by the radio being loose in the tray. After it was tighten it worked fine!
Be sure your radio is in tight. there is a little screw or hex nut on the side (or in the face) to tighten it into the tray. mine was not secured tight to the tray in the panel. after Sarasota Avionics worked for an hour or so with my bad reception it was caused by the radio being loose in the tray. After it was tighten it worked fine!
Walt
Well Known Member
I've had good luck with ACF-50.
Loosen and retighten the screws a few times, that usually improves the contact.
Personally I like to remove the paint under the antenna for the best contact.
No way to check resistance unless you have a Milliohm meter.
