sbarger24

sbarger24

Well Known Member
Alright guys I need your help or suggestions here. I really didn?t notice a radio performance issue until today, when I made my first cross country with Bob Mills (just out of phase I). Bob Mills and I could hear each other fine, as we were flying right next to each other. We were flying over to California to meet up with some fellow RVers. About 30 miles out Bob starts talking to the group we are meeting up with, and I can?t hear them at all. They apparently can hear me just fine, but I?m not picking up their transmission at all, until we reach about 10 miles out where they come in crystal clear.

I noticed in Phase I that there were days where I couldn?t pick up the AWOS until about 6 or 7 miles out and blamed it on the AWOS receiver. I have an ICOM 210; RAMI bent whip belly antenna, and a FlightCom 403 intercom. My COAX is RG-400.

Is there any adjustment on my ICOM 210 radio that would improve my performance? Do you think it is a wiring issue or and Antenna issue?
 
hmmmm...

Steve - Flying with Mills alone could be the cause of many of your issues!!!

I'd check the basics - coax connections at the radio and at the antenna. Make sure you have solid connection to the aircraft for a ground plane at the base of the antenna.

Where on the belly is the antenna mounted? Could it have been in the shadow of a gear leg that was blocking the signal?

Any chance to do a quick swap with another 210 to see if it is any better?

The fact that they could hear you, but you not them may point to an intercom/audio issue - especially since you said they were not audible and then very clear at 10 miles out.

Sorry for nothing specific - just some places to look.
 
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petehowell said:
Steve - Flying with Mills alone could the cause of many of your issues!!!
Click to expand...

I tried to tell him that Pete! (See this thread.)

One of the Ravens suggested there might be a squelch adjustment on the back of the ICOM. Steve's gonna pull the book and look. Might be a normal squelch knob to play with too, but I think Steve tried that.

We can try one of my spare CI-122s (unmodified...not one from our other experiments Pete! ;))

Will try all the connections too. It happened both directions (pointing toward the others and away...shoulda had him do a 360 to see if he heard then lost a long count from the others. Can do that up here).

Any thoughts from ICOM users appreciated. Pete, most of your thoughts are also appreciated! :p

So what's a newly-out-of-Phase-I RV-7A look like on its first flight over the mountains and and back, with its builder and owner fresh off his first formation ride-along:

srv72.jpg


Pretty cool! Look close, I know there's an RV grin in there! Tahoe and the Sierras, with a new (and deep) coat of snow, make a nice backdrop, eh!

Oh, yeah, this is about the radio! :eek:

Cheers,
Bob
 
The A210 has electronic squelch. It is in the setup menu.

Mine had a problem at first but it ended up being a bad connector.

The way to rule out the antenna and feedline is with a VSWR meter.
 
My first thought is your coax connectors, Did you make them. If so go to
Radio Shack and buy an RG58 cable and use it instead of your homemade cable. Secure it under carpet and go fly talking to everyone and ask where they are for distance purposes. A $9 cable rules out so much. I had the same issue and found my B&C connections were just a little short for the center connector pin. This solved my problem

Best, Tad
 
tadsargent said:
My first thought is your coax connectors, Did you make them. If so go to
Radio Shack and buy an RG58 cable and use it instead of your homemade cable. Secure it under carpet and go fly talking to everyone and ask where they are for distance purposes. A $9 cable rules out so much. I had the same issue and found my B&C connections were just a little short for the center connector pin. This solved my problem
Click to expand...

My coax cable had one thin wire from the shield, that grounded out the center lead.........and lead to radio reciever problems. It was one that I put together. I have a Garmin SL-40 & Icom A-210. Both are comparible when it comes to range.....when the cable is good.. :)

L.Adamson --- RV6A
 
A-210

Brantel is right on with his suggestions. If this doesn't fix it then the problem is more than likely internal receiver sensitivity across the frequency spectrum and would require alignment by a reputable avionics shop, i.e. not too sensitive at one place on band from 118 mhz-to 135mhz but within specifications across entire band. I hope this isn't more confusion but what a shop may find internally.
Jerry:eek:
 
L. Adamson, I chased this rabbit for months and even had Kahuna a EE trouble shoot with me. I have a 430 and SL40 that worked perfectly when installed until I decided to UPGRADE to RG400 and made the connections myself that the problem surfaced. I am now branded with poor wiring skills and this may take years of therapy to overcome.

SBarger24 report back your results to end this debate.

Merry Christmas to all
Tad
 
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sbarger24 said:
They apparently can hear me just fine, but I?m not picking up their transmission at all, until we reach about 10 miles out where they come in crystal clear.
Click to expand...

If you can transmit ok then chances are it just the squech setting. Not familiar with the ICOM but I'm sure there is a way to adjust it in one of the menus.
 
Thanks for all the suggestions I may try to get my hands on a meter if not I will buy some cheap RG-58 and see if that fixes the issue. I made my own connections on my RG-400 and wired the radio, so it could easily be an issue there.:eek:

Thanks for the picture Bob had a great time!:)
 
Squelch ...

The fact that it works at all is encouraging. The transmission signal is much stronger than the signals received so the coax and connections could reasonably cause your problems. The other is the squelch which only affects the receiver so that should be adjusted first. I doubt that you can get into sensitivity adjustments.

Bob Axsom
 
It is strange that this problem only cropped up now. I would have expected it to be evident when you were giving the radios a good functional test during Phase One testing. I spent quite a bit of time listening to ATIS broadcasts from stations a long ways away doing a series of small turns to put the stations at all azimuths. I also checked out transmission range to distant stations at various azimuths.
 
Lots of great suggestions, will help Steve follow up, and hopefully apply some lessons learned from here and from the Howell-Mills antenna testing keystone cops consortium :p.

Brantel, thanks and fingers are crossed for e-squelch, but coax crimpers and a helpful avionics shop are nearby!

Stripes, thanks, and at least it didn't end up as a new call sign! ;)

Mike, concur with Steve...this side of the mountains are calling to you!! Minden has a good brunch!!

Kevin, good point...he said he had sporadic trouble with ASOS, but not sure if he did much playing with approach during (the recent) phase I. Good suggestion to do all-azimuth, varying range testing, versus a simple "how do you hear" check. I do that with new antenna mods, but didn't when I intalled a new SL-40 and CI-122 in mine a couple years ago (bad on me!). Another great idea for the stack of test cards.

Thanks to all for the suggestions...d'ya find the book yet Steve!? :)

Alas, another test flight to fly (yippee!) I'll go north, you go south! :D

Cheers,
Bob
 
Thanks everyone for your help! Bob I'm actually on my way to Nebraska to see family via your airline. Will get touch with you when I get back in about aweek
 
sbarger24 said:
Thanks everyone for your help! Bob I'm actually on my way to Nebraska to see family via your airline. Will get touch with you when I get back in about aweek
Click to expand...

Say (crackle, crackle) again (crackle, crackle) please...I can't hear ya!

(oooh, bad XMAS Eve joke!) :p:D

Merry Christmas Steve...have a great visit (and good choice of sleigh to get home!)

Cheers,
Bob
 
Hey Steve,
I have a VSWR meter if you want to borrow it. I don't think it's an antenna issue, though. Let me know when you're coming up and we can check things out.
 
You don't need to go to the trouble of getting a meter and checking SWR - if people hear you fine 30 miles away, your antenna is working fine. You can generally RECEIVE ok even with a crummy antenna - so the problem was almost definitely bad squelch setting as Brantel suggested.
 
Pat Stewart said:
Is it possible that you have a bent whip and the guy flying with you had a straight antenna.

Pat
Click to expand...

Pat,

The guy next to him that day (me) has a CI-122 bent whip. Steve's is a bent whip as well, but don't know what brand. The folks in the distance that could hear him but he could not here...not sure...will ask. What are your thoughts on this...might help us troubleshoot. Thanks!

Cheers,
Bob
 
If they can hear you, you should be able to hear them, especially aircraft to aircraft, where power levels (8~10W) and antennas are similar. Check squelch first, since it is an easy fix.

To open up the squelch all the way: push the volume knob (displays "TEST"). If you can hear the other aircraft/ground stations, then adjust the squelch. If you can be heard by others, but pushing the volume knob does not allow the other station to be heard in your receiver, then you have a bigger problem to troubleshoot. (Push volume again to turn off test)

ICOM A210 Menu Mode:
(to adjust squelch)
  1. Power on radio
  2. If in memory mode, push [RCL] to go to frequency (VFO) entry mode
  3. Push and hold [RCL] for 2 seconds to enter MENU mode
  4. Rotate outside dial until it reads "SQL LEVEL" (not MIC1/MIC2/FM SQL)
  5. Rotate inside dial to adjust
  6. Push [RCL] to exit menu mode
Tune to an unused channel (no CTAF, AWOS, tower, etc). Change the squelch until the noise appears, then back off a couple of settings to keep nuisance trips minimal.
 
I had this same problem a few years back in one of my RV8's. There was a discussion on this site about straight antenna performance vs. a bent whip. I ended up straightening both my antennas (careful I snapped one of them).

That made a big difference on the long distance communications however local radio communications had never been a problem. Not sure I would bother doing that again.

Pat
 
Thanks for the information on the ICOM Menu Mode, I plan on adjusting the squelch before doing anything else. I have a feeling that it may be as simple as the squelch setting as everything works so well and clear except for recieving from a distance greater than 10 miles.

I will keep everyone updated on what I find, unfortunately because of work and the Holidays I won't be around my airplane until January 8th. Thanks again for all the help!:)
 
It is not the bent whip antenna

I have the same set-up, bent whip under the belly and Icom A200. I have great reception (100 miles at 3000 ft) and no complaints with my transmissions at my towered airport. Your issue is not the type of antenna.
 
I think I found the issue........

My radio was not fully pushed into the mounting tray. The rim around the radio was actually contacting the instrument panel before fully engaging into the tray. After some trimming it seems to be fully recessed into the tray. I did a test flight and was able to talk to traffic up to 50 miles away. I don't think that is too bad considering I had a mountain range between myself and them.

Thanks for all of your help!

Steve
 
sbarger24 said:
My radio was not fully pushed into the mounting tray. The rim around the radio was actually contacting the instrument panel before fully engaging into the tray.
Click to expand...
Interesting. It might be worth passing a comment on to ICOM that they should add a connector engagement check to their installation manual. A check similar to the one in the GNS 430 installation manual might work, but the number of turns for the pass/fail criteria in step 4 might be different for this radio.

From the GNS 430 installation manual:
  1. Turn on the 400W Series unit, and turn on the avionics master switch (if applicable).
  2. Place the 400W Series unit in the rack and engage the pawl mechanism.
  3. Turn the Allen screw of the locking pawl slowly clockwise until the 400W Series unit just comes on. A ?T? handle makes the turns easy to count, but do not over-tighten.
  4. Count the number of complete revolutions you can turn the Allen screw until it can not turn any more (but take care not to over-tighten). Three turns is the minimum for proper installation. If fewer than three turns are possible, the mounting rack should be moved aft (toward the pilot) such that the aircraft panel does not obstruct the unit from engaging in the rack.
 
I'm glad you found your fix! We'll keep an eye out for seating depth when we install into my father in law's 6A.
 
Steve,

Glad you found the bogey! Guess we need to come up with a flight to test it further, eh! :D

And good info Kevin!

Cheers,
Bob
 
Reseat the ...

This is one of the first things that techs do whether it is a plug in component, a card or a whole unit. Since the radio functioned properly this was a performance issue as stated in the thread title. I doubt that there is a self test (aka built in test) on a common GA radio that is going to detect performance issues where the radio does everything it is supposed to do but not as well as it can. The man in the loop detected the performance issue and corrected it. The reaction of this super person could well have been silence - it is really a good thing to complete the story as he did. Good job done well - It benefits many.

Bob Axsom
 
I'll take you up on a test flight Bob, just to verify that it is working well.

Before changing the depth of the radio in the tray, what I found was that the BNC adapter on the tray seemed to have some movement with the radio engaged. Now that I have the radio engaged farther in the tray the BNC adapter seems to be tight like it is fully engaged into the radio. It was probably just making a partial connection before.
 
Captivated BNC

Not all BNC coneectors have a captivated center conductor. If a BNC does not have this feature, it is possible that if you have a bend in the cable near the plug, the center conductor may be pulled back and even though the bayonet is engaged, the center conductor does not make contact, and the signals will be very weak.
 
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