Some Questions Regarding Part 15 AM Broadcasting in C-QUAM Stereo using A Mono Transmitter

[cc333]

I'm considering saving up for something like the Hamilton Rangemaster AM1000, because it's FCC certified, and pretty much a nice, all in one package that includes a built in antenna and ATU (both would be an improvement over the DIY setup I have now, which is neither certified nor equipped with an antenna tuner).

However, the AM1000 only broadcasts in mono, and I'm liking the stereo sound of my current setup, so is it possible to adapt the AM1000 to broadcast in stereo, and if so, how?

Can I simply get an exciter and feed the output of that into the transmitter's audio input, or do I need to modify something or find a special transmitter designed with stereo in mind?

Thank you!

c

 

[Kelly A]

However, the AM1000 only broadcasts in mono, and I'm liking the stereo sound of my current setup, so is it possible to adapt the AM1000 to broadcast in stereo, and if so, how?

Couple things come to mind: Even a used CQUAM exciter would cost ten times more to purchase and change frequencies on, than this flea power transmitter in a project box. You'd be better off consulting with this Keith guy who builds the Bassmaster AM1000 to see if an external exciter would even work with his box.

 

[cc333]

Ah, so the C-QUAM exciters are frequency specific? Hmm.

Cost is a concerned because I have a flea-sized budget, so perhaps I can be content with mono (it's not like AM Stereo tuners are especially common, so it really doesn't matter too much whether my signal is in stereo or not, I suppose).

c

 

[Kelly A]

While looking for something else on EBay, found you these two options:

Motorola CQUAM AM Stereo Exciter & Modulation Monitor - Tested, Working | eBay

Find many great new & used options and get the best deals for Motorola CQUAM AM Stereo Exciter & Modulation Monitor - Tested, Working at the best online prices at eBay! Free shipping for many products!

www.ebay.com

And, if you feel like building an AM stereo transmitter:

AM C-QUAM stereo transmitter kit | eBay

Find many great new & used options and get the best deals for AM C-QUAM stereo transmitter kit at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[cc333]

That first link (Motorola exciter and modulation monitor) is tempting. Can I use it with any mono transmitter, such as the Rangemaster?

The second link I've been looking at off and on for over a year, but I settled on the ASMAX because I liked that it had a modulation readout.

c

 

[speer360]

That first link (Motorola exciter and modulation monitor) is tempting. Can I use it with any mono transmitter, such as the Rangemaster?

"The exciter is currently set for 1490kc."

 

[ContinuousWave]

CQuam exciters take the L and R and create the Quam L-R on carrier and combine the L+R after delays to feed the mono input of the xmtr... The exciter operates at four times the frequency because it needs to generate the 0 and 90° out of phase signals that is used by the I and Q modulators on frequency.. You can build a simple exciter section using the schematics from the Chris Cuff transmitters and then feed that to your Rangemaster... It's not that hard

 

[cc333]

"The exciter is currently set for 1490kc."

Right. It'd probably need a crystal, etc, to set for another frequency, like, say, 1610.

CQuam exciters take the L and R and create the Quam L-R on carrier and combine the L+R after delays to feed the mono input of the xmtr... The exciter operates at four times the frequency because it needs to generate the 0 and 90° out of phase signals that is used by the I and Q modulators on frequency.. You can build a simple exciter section using the schematics from the Chris Cuff transmitters and then feed that to your Rangemaster... It's not that hard

So I can find or make an exciter and I just feed its output to any old transmitter? That's what I wanted to know!

Thank you!

c

 

[ContinuousWave]

Right. It'd probably need a crystal, etc, to set for another frequency, like, say, 1610.


So I can find or make an exciter and I just feed its output to any old transmitter? That's what I wanted to know!

Thank you!

c

CQuam exciters are designed to replace the xtal in the transmitter and feed any mono transmitter to make it stereo..you just need to hook it up correct...you'll need a new xtal at 4x the frequency.. www.Klove.nl can make them..