Issue #26: Guest Article - The RFBitBanger Transceiver and SCAMP Digital Mode

Hello T&E readers on QRZ.com . . . Our latest article is all about a brand new QRP transceiver, developed by Dr. Daniel Marks to support emergency communications. Dan's article details the radio, now a very unique kit being offered for $150, and describes the new Digital Mode he developed to support this radio. Now, alpha-numeric messages can be sent without the need for an external computer, making it the perfect mode for EmComm. And, on top of that, it sends CW and SSB! Dan and Dave will answer your questions in this forum discussion. If you missed the original discussion, it is available at this link on the QRZ home page. (You're missing quite a bit if you have QRZ access set up for some page other than Home). Regards, Dave Jensen W7DGJ

 

What a fantastic idea! This kit will be on my ever growing bucket list...

 

Thanks Chuck. I'm hankering to order one of these as well. I really like the idea of the new digital mode, and I can definitely see how this will impact the "prepper" ham community in particular. But, it would be great fun to have a digital mode that worked from a mountaintop without a laptop computer to drag along! And, what's the worst case here, you plug in a key and do CW? Cool! Dave

 

I am aware of the potential utility of the RFBitBanger to preppers, which is fine, but I have more generally been uneasy at what's been going on for the last few years. I think what the electronic industry material shortages show is that unfortunately the virtuous cycle of technological improvement can go backwards because if one industry falters, other industries that depend on that industry can also falter as well, and many industries are now dependent on electronics and computers to function. The RFBitBanger is intended to be an example of technological resilience which minimizes the need for the most advanced electronics to make a long distance communications radio.

Thanks for your interest because I think the ideas of technological resilience should get more attention.

 

Very interesting, probably need to do more research on this topic!

73

 

I have a question for Dan . . . I know when you developed it, Dan, that SCAMP was for emergency use as you wanted an easy-to-build radio that could send and receive a digital mode without needing an external computer. But was it also something that could be picked up by the digital ham to have fun with on a Saturday morning? Or is it a mode that you think will only be for EmComm use in some future scenario?

 

I have been corresponding with W1HKJ regarding possibly including SCAMP as a mode supported by fldigi so that it can be a mode usable for ordinary QSOs and not just for emergencies. It is quite possible to implement SCAMP on a standard computer, soundcard, and transceiver setup. Communication between the RFBitBanger as a DSB receiver and a transceiver in USB should be relatively straightforward. One potential difference is that SCAMP is designed to be usable even if the sideband setting is reversed (that is, LSB is configured for USB or vice-versa) as this just swaps the mark and space tones. An implementation on a SSB receiver needs to determine at the beginning of a transmission if the space tone frequency is less than or greater than the mark tone frequency, in case the transmitter has its sideband setting wrong.

Some have asked for a version of the RFBitBanger that basically acts just as a modem without including the RF transceiver so that it could be connected between a computer and a transceiver. I have not quite worked out all of the details of this. If the transceiver is configured with the correct RIT (receiver incremental tuning) this should work fine, but if for some reason it is not possible to configure RIT getting the modem to work correctly with the transceiver gets more complicated. I would like SCAMP to be somewhat tolerant of configuration errors or radio limitations.

So the short answer is yes, it should be quite usable as a mode for ordinary QSOs. A complication comes in to ensure that two stations with opposite sideband configurations can still talk to each other, but I think that will be worked out.

 

The initial 95 RFBitBanger kits have sold out. More will be offered soon.

 

This is great Dan! I hope that one reason for this was your article here, Dave

 

I would buy this just for SCAMP.