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The Bitx uses a Double Balanced Modulator (DBM). If it's truly balanced it doesn't generate a carrier, just the two sidebands. If it didn't, it's unlikely the crystal filter could remove the carrier.

Wow, thanks for the all the replies! It makes good sense now - understanding how the crystal filter works really helps me wrap my head around the whole thing. Allard, thanks for that link - it is

Congratulations to you and your daughter getting your tickets. I wish her luck on the general class exam. I would build the bitx stock and run it for a few weeks, then upgrade to one of Allard's

Somebody already has. Michael (WA6ISP) did it, I think. There's another one out there somewhere too. I'm sure Michael will chime in shortly. Vince. -- Michigan VHF Corp. http://www.nobucks.net/

HI Allard and all on the group I do not know about aruino programming, my query is simple, maybe the answer is difficult. It is possible to modify the raduino sketch, to use a rotary encoder instead

There is an excellent posting by Jerry Gaffke, KE7ER, that explains it all: /g/BITX20/message/24724 73 Allard PE1NWL

Apologies... I oversimplified and therefore stated wrong. I should have written...? ''That we can pass the carrier and a small portion of each sideband by changing the frequency of the signal that we

Maybe just a little more clarification on that. When you mix and take the sum, you don't change the side band. When you mix and take the difference, you actually invert the side band. The relationship

The crystal filter is just a gateway it doesn't carevwhat type of rf gets through...? We're simply choosing which half of an am signal to pass...? By moving the signal up or down the spectrum by

Yeah you could try an external pull up resistor of 10-47K. Perhaps the internal pull up resistor is faulty. 73 Allard PE1NWL

Gordon, thanks for that explanation. Although I understand sidebands in general, I now better understand how the crystal filter works! 73! -- Ryan Flowers - W7RLF MiscDotGeek.com (

Hmmm.... some confusion here. If double sideband looks like ..;;\\ //;;.. then upper sideband looks like //;;.. no matter whetehr it is made by a bitx, an iCOM or a Heahtkit...... In all cases, the

Perhaps, I'll have to check that. However, both my test sketch and the B40 sketch are using the same hardware and setting or attempting to set the same 5Mhz frequency on the AD9850.? With that set of

Richie, ok so I guess the passband crystal filter is symmetric in which case it doesn't care. Gordon, so if the receiver is decoding in USB and receives a USB signal like "..::?" (as would come from

?typo: meanto to say, ""the filter can't tell and doesn't care whether the spectrum going through it is upper or lower sideband" ________________________________ Sent: Tuesday, November 28, 2017 12:35

?the filter can tell and doesn't care whether the spectrum going through it is upper or lower sideband..... What makes it upper or lower sideband is the relative relationships between the radio

Hey David, I figured this out last year when I could never resolve SSB in any superhet that I built. I got a copy of EMRFD and it all came together. Here is my attempt at explaining it. First, the

Hi Allard at A2 I measure 2V and can not find any short to ground. Next thing I will try to wire a resitor from A2 to +5V and see what happens - comming back. Thanks Gert

So, as I understand it, a SSB signal is where half of an AM signal and the carrier are suppressed. For illustrative purposes, I'll draw a full AM signal like ..::||::.., where || is the carrier and

?Getting it to do upper side band isn't that terribly difficult, a small mod or two in the raduino sketch will do it ---- but it is just as easy to upload one of Allards' sketches and then it handles