A mystery on MW this AM . . .

[KB2GOM]

So, before I fire up the Commuter Assistance Net on 2 meters, I am fooling around with the CCrane EP PRO on medium wave

If you are unfamiliar with the EP PRO, it has the heart of a digital radio but the user interface of an analog radio, ie, slide-rule tuning with no digital readout.

It was created by Bob Crane because his mother wanted a really simple radio that was easy to operate. I did a write-up on it here: Sometimes simple works . . . really well! Exploring the CCrane EP PRO

Because the EP PRO has digital innards, there is a switch on the back for choosing between 10 kHz (North America) and 9 kHz (Europe) tuning steps.

I switch it to 9 kHz tuning steps, hoping to hear something from across the pond. Around 10:40 UTC, I am tuning around 1600 when I come across a religious broadcaster with people speaking American English. It sounds loud and clear. I switch the EP PRO to 10 kHz tuning steps, and the station vanishes. Wiggling the tuning knob, I can't find it.

I switch back to 9 kHz tuning steps . . . there it is. Because the EP PRO does not have a digital readout, I don't know where -- exactly -- I am tuned.

In quick succession, I fire up a Tecsun PL880, a CCrane Skywave, and my Grundig 800 (hooked to an MFJ 1886). I tune around with each and cannot find the station. I go back to the EP PRO, and the station is still there, but faint.

As 11:00 UTC rolls around, the station fades before I can hear an ID.

Does anyone have a clue what it might be?

 

[buddrousa]

I think Belize is American English not sure about their radio systems. I went to airpack repair class with 3 from Belize.

 

[WA8ZTZ]

AFAIK, Belize is all FM.

The fact that none of the three other radios heard the signal makes me wonder if you have some sort of spurious response in the EP Pro.
In other words, you may be hearing a mixing product on 1600 and not an actual station on that frequency. Do you have strong local AM stations near your QTH? These can be a problem when it comes to mixing. This sort of thing can be almost impossible to track down to the actual cause.

Another thing that has me scratching my head is an analog slide rule dial tuning with selectable 9/10 kc tuning steps.
How does that work?

 

[hill]

9/10 kc tuning steps

More than likely, it adjusts the bandwidth of incoming signal based on the switch position to match the receiving station.

 

[WA8ZTZ]

OK, did a little quick research... my original Radio EP seems to tune in truly analog fashion. However, with your newer EP Pro, the tuning seems to be digital and the slide rule dial is a mechanical face, hence its ability to tune in 9 or 10 kc clicks.

Otherwise, based on your original post, my guess is that what you heard on 1600 was a spur.

 

[wenzeslaus]

Does anyone have a clue what it might be?

here's some clues. 32 results.

Radio Station Finder: Search Results

 

[KB2GOM]

here's some clues. 32 results.

Radio Station Finder: Search Results

Wow, thanks!

 

[WA8ZTZ]

The nearest European channel to 1600 is 1602. If you were tuned to 1602, the bandwidth of your radio is such that you would have heard a station on 1600. Of the 60 or so stations on 1600, only 3 (located in FL, OH, and TN) have a religious format. Their nighttime power is all below 100 watts. The TN station is 50kw non-directional daytime so if it were running full power at night for some reason then that could be a possibility, but such is unlikely.

Again, since none of the other three radios heard the station, you may well have been hearing a mixing product.

 

[Boombox]

Another thing that has me scratching my head is an analog slide rule dial tuning with selectable 9/10 kc tuning steps.
How does that work?

SiLabs has a DSP chip that can be tuned using a potentiometer (I have three radios that use one of these chips, my Radio Shack Pocket Radio, my XHDATA D-328 and a D-219). When you tune up and down the MW band (or SW bands) you can hear the DSP chip sort of 'ratchet' its way up and down the spectrum.

So, with this DSP chip, the software inside the chip is doing the actual 'tuning', and the potentiometer is telling the DSP chip whether to go up, or go down, in frequency. The 9 kHz / 10 kHz switch undoubtedly tells the chip which intervals to use when tuning up or down the MW band -- to go in 9 kHz 'jumps', or 10 kHz 'jumps'.