Much of today was spent working on a parts list for the Deep Voice long wave transmitter.
In the last post, half-a-month ago, I said I'd update the project page, which I did, but I forgot to upload it. Now tht's done:
http://www.kdxradio.com/deepvoice.html
Per RFB's suggestion, the oscillator will be a Datakit PLL Oscillator instead of custom crystals, which will be more versatile in the long run and probably less expensive.
No one has answered me yet whether the U.S. spacing for long wave is 9kHz or 10kHz. Is there a standard? The frequencies usually listed for part 15 use have 9kHz spacing.
There is no Longwave Standard in the U.S simply because Longwave is not allocated in America.
That being said the 162 Primary and 189 secondary should work just fine.
Well I think then the obvious thing to follow would be the most common channel spacing on radios sitting on the store shelves..ie wally worlds and rat shacks.
I was thinking of setting mine up to operate on 167Khz, to mirror the MW 1670 frequency. It's just too bad I cant transmit on 167Mhz for FM!
Oh well...maybe next time!
RFB
By using the Datakit PLL Experimenter Board as the oscillator for long wave, it will be possible to choose either spacing.
15.217 assigns 160 to 190 kHz for part 15 at 1-Watt.
My Sangeon, made for the American market, is normalized for 9kHz spacing, with frequencies of 162, 171, 180 & 189kHz.
By pressing the rotary tuning knob I get 1kHz spacing, giving a total of 39 channels within the allowed space.
I cannot set the radio for 10 kHz spacing on LW.
The radio cannot be set to 167kHz.
Carl Blare hit my point.
Since the US hasn't allocated Longwave there is only the 9khz spacing standard. Everyone else seems to use 9khz spacing excluding North America.
That Being said 167 cannot be used on a digitally tuned radio, unless you change the tuning setting to 1khz steps.
That's why I suggested a standard set of two easily found Frequencies, that go around the DXd 171. It will be hard enough getting an average Joe to use longwave, it would be even harder to get Joe to change the settings on his radio just because the station liked one set of numbers that weren't "normal".
That being said, you would have no problem on Analog tuned radios.
The project link now shows Version 1.0.0 of the Deep Voice long wave transmitter, which depends on ordering custom crystals. The schematic is viewable at this link
http://www.kdxradio.com/deepvoice.html
Today I mapped out the parts list and schematic Version 2.0.0 which uses a PLL Datakit as a programmable oscillator, a more versatile method proposed by RFB. In a few days I'll get this new version posted on the website.
We are getting close to having our own long wave transmitter design.
I would not go that far in saying 9khz is the standard when there is no standard officially declared for LW in the US. With that in mind, and all you have to do is simply take a stroll down the radio isle in wally world, and see how many of those radios with LW are either analog tuned or digital with 1khz spacing. I have yet to see a common radio under 30 bucks with LW and it only tunes in 9khz steps..they all are analog tuning or digital with 1khz.
Now the pricey units either have 1 or 9, or a selector to choose between the spacing. From the consumer point of view, I would spend the 30 bucks to try tuning a band for a station that no one uses..but more than that...it would not be worth the extra cost to listen to static, or only 1 station barely being picked up out of the AC noise and buzz saw junk.
Dedicated DX radio enthusiasts and the general public are two different things all together. I do not intend to just broadcast to radio enthusiasts sporting a room full of radios where only one can be heard at a time. I want to broadcast to the general public..the numbers are far greater. But first they have to be informed about that band and informed that they do not have to spend a huge amount on a radio just to tune in 1 station surrounded by noise and convinced that tuning in regularly is as viable as they tune in to their hip hop or bubble gum FM music stations.
Heck it is difficult building an audience base even for our flea FM's and AM's. The LW will not be any easier..in fact I believe it will be even more difficult simply due to the lack of awareness about the band in the public realm.
RFB
The Datakit PLL Programmable Oscillator is now on order.
Now I am reviewing other parts needs for building the Deep Voice LE transmitter, and I have a question about this simulated final stage from radio8z
C2 is .039uF, and C6 is 39nF. In actual fact, isn't that really one and the same value? (which can be stated either way?)
Some modification required, but can be used to up-convert the LW signal to be received by an AM radio on 1000Khz or whatever.
RFB
It also looks like the converter circuit could make 13.560mHz pop over to the AM band.
Nice idea.
Yep. I posted the links over in the 13.560 thread too!
I was going over our discussions on building converters and remembered that little gem.
RFB
Schematic Version 2.0.0 is now on the Deep Voice Long Wave page showing the version with RFB's PLL Datalink Oscillator, which has a keyboard for changing frequency to virtually ANY frequency!
http://www.kdxradio.com/deepvoice.html
I've begun ordering the parts and will be building the first prototype of this new device.
The Datalink PLL kit arrived and after studying the documentation I see that it will not be a simple build and start project for long wave use.
The paper says it is not a complete kit. One must add or change parts as needed for a desired purpose. For example, it comes with a 10kHz crystal, but the objective frequencies for this design will require a 9kHz crystal, easy enough to solve. But there's more to it than that and as time goes on I'll be consulting with RFB who already has experience with the device and hopefully will be able to describe exactly what to do next.
Because of being set back into a vague zone for the time being, I'm going to revive plans to build the other version, 1.0.0, which simply needs particular crystals. It may prove to be easier, but we shall see.
In the end I hope to have both versions running.
The Datalink PLL kit arrived and after studying the documentation I see that it will not be a simple build and start project for long wave use.
The paper says it is not a complete kit. One must add or change parts as needed for a desired purpose. For example, it comes with a 10kHz crystal, but the objective frequencies for this design will require a 9kHz crystal, easy enough to solve. But there's more to it than that and as time goes on I'll be consulting with RFB who already has experience with the device and hopefully will be able to describe exactly what to do next.
Because of being set back into a vague zone for the time being, I'm going to revive plans to build the other version, 1.0.0, which simply needs particular crystals. It may prove to be easier, but we shall see.
In the end I hope to have both versions running.
Simply punch in 000016, the yellow LED flashes indicating it took the number. Then use the UP key to step up 1Khz steps to 162. For 170 punch in 000017.
The on board PLL filtering is adequate for controlling a plain ol oscillator. Since modulation takes place outside of the PLL and oscillator itself, there is no reason to do any changing to the PLL sensing and loop paths or the PLL crystal.
Only thing necessary to add to the PLL board is an oscillator capable of generating the frequencies needed here...ie 162Khz and 170khz.
RFB