What Are These Freqs For?

[mfn002]

Since this has to do with utility stations, I guess I'll put this here...

I recently acquired a strange piece of aircraft radio gear on eBay (Listing picture at bottom of post).

Anyway, it is made by Gables Engineering and has a three-pin connector on the back for lighting. The frequencies it shows are listed sequentially and have a letter/number designation next to them. There are around 100+ of these frequencies listed. They are generally in the 2, 3, 4, 5, 6, 8, 10, 11, 13, 15 and 17 MHz ranges:

02931.00...1A
02987.00...1B
02945.00...1C
02868.00...1D
05000.00...1E
03001.00...1F
02889.00...1G
02182.00...1H
05610.00...2A
05673.00...2B
05638.00...2C
05624.00...2D
10000.00...2E
05652.00...2F
05533.00...2G
03023.50...2H
08945.00...3A
08889.00...3B
08854.00...3C
08910.00...3D
15000.00...3E
08868.00...3F
08833.00...3G
13328.00...4A
13288.00...4B
13352.00...4C
13272.00...4F
13312.00...4G
02454.00...7A
03404.00...7B
04696.00...7C
05589.00...7D
06603.00...7E
08847.00...7F
10049.00...7G
13304.00...7H
02854.00...8A
03411.00...8B
05454.00...8C
05603.00...8D
06610.00...8E
08875.00...8F
10073.00...8G
13320.00...8H
02875.00...9A
03425.00...9B
05484.00...9C
05642.00...9D
06617.00...9E
08882.00...9F
11279.00...9G
13336.00...9H
02882.00...11A
03432.00...11B
05491.00...11C
05645.00...11D
06624.00...11E
08903.00...11F
11303.00...11G
13344.00...11H
02896.00...12A
03446.00...12B
05498.00...12C
05659.00...12D
06631.00...12E
08924.00...12F
11319.00...12G
17909.00...12H
02901.00...13A
03460.00...13B
05505.00...13C
05680.00...13D
06638.00...13E
08931.00...13F
11327.00...13G
17917.00...13H
02924.00...15A
03467.00...15B
05519.00...15C
06540.00...15D
06645.00...15E
08938.00...15F
11343.00...15G
17925.00...15H
02938.00...16A
03481.00...16B
05554.00...16C
06561.00...16D
06666.00...16E
08959.00...16F
11367.00...16G
17941.00...16H
02952.00...17A
03495.00...17B
05561.00...17C
06568.00...17D
06680.00...17E
10009.00...17F
11391.00...17G
17949.00...17H
02966.00...19A
04675.00...19B
05568.00...19C
06575.00...19D
08819.00...19E
10017.00...19F
13264.00...19G
17965.00...19H
02973.00...20A
04689.00...20B
05575.00...20C
06582.00...20D
08826.00...20E
10025.00...20F
13280.00...20G
02980.00...21A
04689.50...21B
05582.00...21C
06581.00...21D
08840.00...21E
10041.00...21F
13296.00...21G

These sound like RDARA frequencies, judging by the alphanumeric designations next to them, but I'm not too sure.

 

[marksmith]

There are some military HF as well as regular HF air frequencies, some time frequencies, and looks like some marine HF.

Mark
WS1095/536/436/996P2/HP1e/HP2e/996XT/325P2/396XT/PRO668/PSR800/PRO652

 

[mfn002]

There are some military HF as well as regular HF air frequencies, some time frequencies, and looks like some marine HF.

Mark
WS1095/536/436/996P2/HP1e/HP2e/996XT/325P2/396XT/PRO668/PSR800/PRO652

That's what I kind of suspected, but it seems odd that they are given in order of frequency, not channel. If it helps any, the seller was located in Greece.

 

[ko6jw_2]

I think the grouping are for channels that would be used in a particular area or route. The pilot would select, say group 16, and then channels A-H depending on time of day and propagation conditions. This would eliminate the need to step through hundreds of channels. More modern HF aircraft radios can be tuned into ham bands and you can, once in a while, hear pilots who are hams operating aeronautical mobile.

These radios also need an antenna tuner with the antenna inside the tail of the plane. They always use upper sideband.

 

[mfn002]

I have some photos I took of the inside, back and front of the item. These may help to explain how this thing works.

Sent from my iPhone using Tapatalk

 

[nd5y]

It was made by Gables Engineering Inc

 

[ko6jw_2]

It's a control panel for a radio, not the radio itself.

 

[mfn002]

I do find it odd that someone would go through all that trouble to make a simple list of frequencies.


Sent from my iPhone using Tapatalk

 

[majoco]

There doesn't appear to be anything electrical in there apart from a couple of dial lights so it's not a radio controller - maybe just a memory aid? There's all sorts of frequencies there, marine, aero, time signals, broadcast (not so many). How does the display work - I thought at first it was just a filmstrip but I see you can change individual rows - strange that it some instances the frequencies seem to follow an upward progression 17A-19A-20A for example.What happened to 18A?

 

[mfn002]

Turning the wheels on either side scrolls through the list, which is printed on transparent film. It shows three lines at a time. The channels are listed in order of frequency, lowest to highest. I suspect it is some kind of list that a pilot can consult. I think that the radio it was meant to go with had the frequencies entered as channels, so when the pilot was told to go to 2182, he would select channel "1H" on the radio.

Here's the way it is actually listed on the chart:

1H
7A
8A
1D
9A
11A
1G
12A
13A
15A
1A
16A
1C
17A
19A
20A
21A
1B
1F
2H
7B
8B
9B
11B
12B
13B
15B
16B
17B
19B
20B
21B
7C
1E
8C
9C
11C
12C
13C
15C
2G
16C
17C
19C
20C
21C
7D
8D
2A
2D
2C
9D
11D
2F
12D
2B
13D
15D
16D
17D
19D
20D
21D
7E
8E
9E
11E
12E
13E
15E
16E
17E
19E
20E
3G
21E
7F
3C
3F
8F
9F
3B
11F
3D
12F
13F
15F
3A
16F
2E
17F
19F
20F
21F
7G
8G
9G
11G
12G
13G
15G
16G
17G
19G
4F
20G
4B
21G
7H
4G
8H
4A
9H
11H
4C
3E
12H
13H
15H
16H
17H
19H