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Simple FT8 DSB rig

Adam Rong
 

I built it on my perf board. I made the first QSO days ago with a ham 1168 miles away. It is a 20m DSB 1-watt transceiver with VOX.

Ron Stone
 

Adam - Would love to see the schematic for this baby and your other 20 meter version too.  Thanks!

Ron (KA3J)

Adam Rong
 

Ron,

A kit is being designed based on this circuit. I will announce in a month or two. You will likely see the prototype in digital mode forum in Hamvention this May.

Thanks,
Adam

在 2019年3月29日,上午7:39,Ron Stone <rsstone2@...> 写道:

Adam - Would love to see the schematic for this baby and your other 20 meter version too.  Thanks!

Ron (KA3J)

Ron Stone
 

Adam,

Very good.  I was under the impression that you were just doing a 40 Meter version of this rig.  Sounds like you're planning to do a 20 Meter version as well.  Any chance, you'll sell a version that does not include an enclosure?

73,

Ron (KA3J)

Adam Rong
 

Ron,

The 20-meter version will be announced later. Why a version without an enclosure? Do you plan to integrate to a big system?

Thanks,
Adam

Ron Stone
 

Adam,

Thanks for your response.  I was thinking of combining it with a Raspberry PI and batteries in a single enclosure for portable use, and use my phone for the UI.

73,

Ron (KA3J)

Adam Rong
 

Sounds like a good idea. Here we have a ham already tested this system okay.

Thanks,
Adam

Furtuna Mircea
 

Adam -An excellent idea for this mini transceiver.
If the price will be competitive, it will be a great success.

I do not have crystals for those frequencies, otherwise I try a replica.
Mircea-(YO9IOF)

Adam Rong
 

Thanks Mircea,

The price will be competitive of course. I hope more people can enjoy this tiny radio for portable/mobile operation. I will return home tomorrow after a 10-day trip to restart the test. I should be able to ship in 5 weeks.

Thanks,
Adam

On Wed, Apr 17, 2019 at 1:46 PM Furtuna Mircea via Groups.Io <mircea99fm=yahoo.com@groups.io> wrote:
Adam -An excellent idea for this mini transceiver.
If the price will be competitive, it will be a great success.

I do not have crystals for those frequencies, otherwise I try a replica.
Mircea-(YO9IOF)



--
Thanks,
Adam Rong

Ron Stone
 

Adam,

What do you think of going SSB instead of DSB at least for the transmitter?  I believe this would just involve the addition of a simple 3 pole crystal filter and an additional SA612 mixer circuit - not many components at all.  Suitable crystals for 20 meters are readily available - 4 MHz for the crystal filter and 10,073 MHz for the mixer (or 4 MHz and 3.072 MHz for 40 meters) which would just have to be pulled slightly.  This approach would double the effective power and also keep the channel cleaner - i.e., avoid the unnecessary LSB signal.

73,

Ron (KA3J)

Adam Rong
 

Ron,

I built a SSB FT8 radio based on my KN-Q7A PCB and it works okay. If you check out my previous post, I even added a VOX circuit for this rig.

However this SSB concept is very common, and I am trying something new. The result is very promising and the unwanted LSB band is not so harmful as the power is QRPP level.

Thanks,
Adam