radio frequency setting question

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Matt C

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Matt C
So, I've been having trouble tuning in ATIS and AWOS frequencies given in three decimal place formats on my KX155's as they only go to two decimals. Example - XXX.225. I try tuning to the nearest possible setting and it doesn't work. The radios work fine and have good range on typical two decimal frequencies. I'm interested in using an airport with a tower frequency of XXX.475. I don't want to limit my airport selection by radio frequency. I feel like a moron, but it hasn't really come up before. What am I doing wrong? Thanks in advance.

P.S. My custom installed AoA doesn't tune them in any better. Does the AoA just get me a free pass?
 
Is the kx155 the one where u have to pull the knob out to get that intermediate frequency? Try it out, yo.
 
:yeahthat:
Just tune to the number before that 3rd decimal would appear. Ex. 120.925
So you would dial in 120.92 and then pull out the "25k" knob and it will change to the .925, even though you cannot see it in the display window.
 
Ryanb said:
:yeahthat:
Just tune to the number before that 3rd decimal would appear. Ex. 120.925
So you would dial in 120.92 and then pull out the "25k" knob and it will change to the .925, even though you cannot see it in the display window.
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AH HA! Sneeky - thanks! I saw the 25k tuning but never the digits. Will check it out - thanks all!
 
How hard would it have been to add the capacity to display the extra digit? (rhetorical)
 
Matt C said:
How hard would it have been to add the capacity to display the extra digit? (rhetorical)
Click to expand...

That's one of the advantages of an AOA, and you mentioned you already had one. How's this related to your radio? :dunno:

That's the thing about AOAs, they're ****ing magic! :biggrin:
 
Matt C said:
How hard would it have been to add the capacity to display the extra digit? (rhetorical)
Click to expand...
It's common in older style equipment. The radio's have a frequency spacing of .25khz, which means that any third decimal frequency will either be a 5 or a 0, so it really isn't necessary to display it.

Somebody else will probably be along who can give a better answer.
 
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Ryanb said:
It's common in older style equipment. The radio's have a frequency spacing of .25khz, so any third decimal frequency will either be a 5 or a 0, so it really isn't necessary to display it.

Somebody else will probably be along who can give a better answer.
Click to expand...
Good enough for me, I'm simple. Thanks.
 
Matt C said:
So, I've been having trouble tuning in ATIS and AWOS frequencies given in three decimal place formats on my KX155's as they only go to two decimals. Example - XXX.225. I try tuning to the nearest possible setting and it doesn't work. The radios work fine and have good range on typical two decimal frequencies. I'm interested in using an airport with a tower frequency of XXX.475. I don't want to limit my airport selection by radio frequency. I feel like a moron, but it hasn't really come up before. What am I doing wrong? Thanks in advance.

P.S. My custom installed AoA doesn't tune them in any better. Does the AoA just get me a free pass?
Click to expand...

The manual says "it will change in increments of 50 kHz when the knob is pushed in and 25 kHz when the knob is pulled out.”

The display is in megahertz, or MHz. 50 kHz is the same as .050 MHz.

If the radio is limited to increments of .050 MHz, there’s no way to dial in XXX.225 or XXX.475, because it skips over the .x25 and .x75 frequencies where, when not skipped, the third digit is an implied but not displayed 5.

Their apparent goal is to let you purposely skip the XXX.x25 and XXX.x75 frequencies. That way, I guess, you can quickly move through the more common whole and half frequencies like XXX.x50 and XXX.x00 where the third digit is an implied but not displayed 0.

I vote we keep the knob pulled out and just spin two times faster!

Who's with me? :)
 
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register@teamandras.com said:
I vote we keep the knob pulled out and just spin two times faster!

Who's with me? :)
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Not me.

If you like wearing out "unobtanium" rotary switches in one of the best sounding GA radios ever produced, feel free. I'd like to keep mine operational as long as I can.

Let me guess, you're renting? :)
 
By the way, go count up the number of "splinter" frequencies you'll commonly tune in your local area vs the old frequency scheme. If you're not based somewhere very dense, or flying a lot of IFR, you'll rarely pull that knob out.
 
denverpilot said:
By the way, go count up the number of "splinter" frequencies you'll commonly tune in your local area vs the old frequency scheme. If you're not based somewhere very dense, or flying a lot of IFR, you'll rarely pull that knob out.
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I see it used a lot for WX frequencies. Not much for other stuff.
 
denverpilot said:
By the way, go count up the number of "splinter" frequencies you'll commonly tune in your local area vs the old frequency scheme. If you're not based somewhere very dense, or flying a lot of IFR, you'll rarely pull that knob out.
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Thanks. That makes sense, but I do fly somewhere dense.

I just went south down the coast for a few airports, starting with John Wayne, and compiled this short list of frequencies:

Frequencies.jpg


That seems like enough of a sample. I wouldn't call them splinter frequencies.

Around here, I think it makes sense to keep it pulled out so that all the required frequencies are readily available.

By the way, I once got confused about this like the OP. I landed at Montgomery and tower told me to call ground, but I couldn't reach them for a frustrating minute or two. It seemed like an eternity as my full idiocy was on display. I bet they have that happen off and on at Montgomery.

I certainly understand your mileage may vary if you're in an uncrowded part of the world and they only pop up as a rare exception.
 
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You guys are talking about pulling a knob and 6PC is not involved?
 
register@teamandras.com said:
Thanks. That makes sense, but I do fly somewhere dense.

I just went south down the coast for a few airports, starting with John Wayne, and compiled this short list of frequencies:

Frequencies.jpg


That seems like enough of a sample. I wouldn't call them splinter frequencies.

Around here, I think it makes sense to keep it pulled out so that all the required frequencies are readily available.

By the way, I once got confused about this like the OP. I landed at Montgomery and tower told me to call ground, but I couldn't reach them for a frustrating minute or two. It seemed like an eternity as my full idiocy was on display. I bet they have that happen off and on at Montgomery.

I certainly understand your mileage may vary if you're in an uncrowded part of the world and they only pop up as a rare exception.
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They're called splinter frequencies because that's what they were originally called. They didn't exist long ago, the radios were mandated to switch over to tighter bandwidth standards so they could even exist... :)

Took a long time for most of the fleet to upgrade.

And yeah, you're all packed in like sardines on the coasts, so you'll see more of them there.

Still, if you look over an actual flight, and not just a list of every airport you're flying over and every frequency (you wouldn't talk to ground flying over, or clearance delivery for example), you'll find they're fairly lightly used.

They're used when the overlap on the original frequencies wouldn't work at close ranges, or there's local interference that dictates the spectrum managers use them.

It's really not hard to use the function on the pop out knob radios, it becomes natural, just turn to the next frequency above or below, pull, and one more click, and it's there. It becomes second nature very quickly if you fly behind the King stuff all the time. It's technically a little faster way to get there, too, not that it matters a whole lot.
 
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