Can't receive AWOS with SL40

I have a Garmin SL40 and can’t receive AWOS stations. I understand the SL40 can receive frequencies with three decimal places (e.g. 126.825) by inputting the frequency with only first two decimal places (e.g. 126.82) . The SL40 apparently interprets the third decimal on its own. I have tried to receive several AWOS stations with no luck. Anybody have any idea what I might be doing wrong?

I don't have on of those, but I wonder if you can configure the channel spacing? Try looking on the garmin site for the install and pilot guide. Maybe the spacing is to wide or narrow and is not tuning the third digit the way you need it to?

Jim

All early RV-12's have an SL-40 - - -

and mine works very good. You will likely have to go thru the settings. Have you changed any of the settings ?

I have studied both the User and Install manuals for the SL40 and I see where System Functions can be user adjusted. In fact, I have previously adjusted the sidetone level so I?m familiar with how to make changes to the setup. However, looking at the list of possible user adjustments I don?t see anything pertaining to XXX.xxx or XXX.xx frequency selection.

I have initiated a request for assistance with Garmin and now await their response. I?ll post result here when I get resolution to the problem.

SL40 Comm

From the SL40 manual:

2. Turn the Small, inner knob to change the values in 25 kHz increments. The kHz selection range is
between 000 and 975 kHz in 25 kHz steps. Note that only two digits are displayed to the right of the
decimal point.

From my old notes :

SW VER 2.2
Hdphon 000
Mic 1 Sqlch 058
Mic 2 Sqlch 058
Tranmit Mic 1 & 2
Intcom Lvl 249
Sidton Lvl 040
Lo Dsp Lvl 00
Hi Dsp Lvl 50

I think this is where mine are yet.

Update... Went flying this morning (Easter - wife said OK) and I tried six different AWOS stations and was ready to give up. I tried one more and it works. Is it common for so many AWOS to be off-line? All stations were very easily within range. Glad its working. Love the airplane and love the electronics...

Jim,

Does the radio work with other stations using the .025 increments? Try it with a handheld, look for a pattern. Hard to imagine why only AWOS will not work.

John

Have you tried disabling the squelch while the channel is tune?
Some AWOS xmitters are weak, or the auto squelch level might be turned too high.

BigJohn said:

Jim,

Does the radio work with other stations using the .025 increments? Try it with a handheld, look for a pattern. Hard to imagine why only AWOS will not work.

John

Click to expand...

rvbuilder2002 said:

Have you tried disabling the squelch while the channel is tune?
Some AWOS xmitters are weak, or the auto squelch level might be turned too high.

Click to expand...

Yes I would try to find a pattern using another radio. Some can be picked up at a fair distance others cannot be heard unless you are right on top of them.

I have seen AWOS that were not working and some that are intermittent.

Any time that I cannot hear an AWOS or ATIS, I always attempt to disable the squelch.

Check the

Piper J3 said:

Update... Went flying this morning (Easter - wife said OK) and I tried six different AWOS stations and was ready to give up. I tried one more and it works. Is it common for so many AWOS to be off-line? All stations were very easily within range. Glad its working. Love the airplane and love the electronics...

Click to expand...

I suggest checking the notams for those airports with no service if you haven't already done so. Our airport notams the AWOS o/s if they find out it is inop. Especially if it will be a few days before a tech can come out. Also many AWOS systems have land line capability. Depending what part of the system is in bad order, you may be able to check by calling the phone number. And the fastest way for our airport to find the AWOS is down is for a pilot to let the manager or a lineman know. Call up the airports Unicom frequency next time you are airborne and have them check the AWOS if you are not receiving it. they will appreciate your letting them know if you think it is suspect. Takes about 30 seconds for them to check it. Oh, and yes these systems require maintence and require sensor replacement and calibration and it is fairly common to lose at least part of the system. We have had lightning strikes take ours totally out at least two or three times. Also, it is my experience that AWOS systems vary greatly in transmit range due to terrain, altitude and other factors. I've tuned in to the AWOS at some airports on the standby freq. and decided it was out of service when I couldn't get it 10 mile out, and the pick it up a few miles closer.

Joe

Maybe I wasn't clear in above post. I found one AWOS station that I could receive with XXX.xxx so SL40 is working correctly. It seems that a lot of AWOS stations are not broadcasting in this area. I will expand my list to find other AWOS stations.

So does anybody know if it is common that AWOS stations are not broadcasting?

Piper J3 said:

So does anybody know if it is common that AWOS stations are not broadcasting?

Click to expand...

I apologize Jim. I think my post above came out sounding unintentionally derogatory. I thought having a few methods to help you find out if the AWOS's were in fact bad order would be of help in isolating the problem to your SL40.

From me quoted above:

Oh, and yes these systems require maintenance and require sensor replacement and calibration and it is fairly common to lose at least part of the system. We have had lightning strikes take ours totally out at least two or three times.

Click to expand...

For example if a thunderstorm rolls through an area and it contains heavy lightning it would not be unheard of for AWOS's at multiple airports in the storm path to get storm / lightning damage. High wind can damage transmit antennae and degrade range or knock a system off line.

Although I'm certainly no expert I manage a small regional airport and deal with this 3 or 4 times a year so yes I would say in my experience it is not uncommon. Hope that helps...

Joe

You didn't say how far away form the ASOS stations you were. The AIM says you should be able to receive the ASOS within 25NM.

That could be the problem. I wonder if they use low power RF just to make sure you are truly getting the local weather.

Bought my SL40 with a flying plane around it. I marveled at just how good the radio was compared with any rental radios I've suffered through. Signal reception is very very good. I find it strange that you are having these issues. But I have never adjusted any settings in mine so I can't say how long it took the builder to "set it up."

I fly under NY bravo and the surrounding areas, but I've been from the Canadian border to New Orleans and have never had a problem receiving any station with the exception of Block Island, which I can't generally receive until I am inside 10 miles.

I'm not sure I added anything useful here other than to confirm you should not be having these issue. How is your antenna?

Piper J3 said:

That could be the problem. I wonder if they use low power RF just to make sure you are truly getting the local weather.

Click to expand...

Most of them seem to be rather low power.... That is why in my previous post I asked if you had tried turning off the auto squelch?

If you are very far away, it is common for some of the signals to not be strong enough to un-squelch an SL-40.

I got this response from Garmin Support... If the stations are low power it’s possible the signal is not strong enough to break squelch in the SL 40. The SL 40 receiver squelch adjustment can be adjusted by a Garmin Aviation dealer in test mode.

I will try un-squelch next time I fly.

Thanks everyone for your help...