¿ªÔÆÌåÓý

Date
Re: change keyer type on nextion
Anyone happen to have a version 3 hmi for 3.5"? Thx.
By Sam Tedesco · #66027 ·
Re: DC blocking cap between souncard and ubitc mic input. #ft8 #ubitx
Awesome, it didn¡¯t hit me at first. I just grabbed two off eBay for $11 for both. I have parts I was going to use on interfaces, transformers, optocouplers, the easydigi has all you need. I¡¯ve
By Joe Puma <kd2nfc@...> · #66026 ·
Re: Pseudo-Sine?
Well, where are the harmonics showing up? :) -adrian wrote:
By Adrian Chadd · #66025 ·
Re: Pseudo-Sine?
So, perhaps a dumb question or maybe two .., but "Why the continued instance on using low-pass filters ...Wouldn't some band-pass filters make more sense?? Jim
By jim <ab7vf@...> · #66024 ·
Re: DC blocking cap between souncard and ubitc mic input. #ft8 #ubitx
Joe Puma, yes that is most likely the purpose. Been there, done that, learned a thing.
By Gordon Gibby <ggibby@...> · #66023 ·
Re: Pseudo-Sine?
As I said in post 66008: On Mon, Mar 4, 2019 at 12:03 PM, ajparent1/KB1GMX wrote:
By Jerry Gaffke · #66022 ·
Re: Pseudo-Sine?
Allison, Are you referring to my suggestion of unbalancing the D3,D4 mixer,? CLK2=VFO, CLK1=45mhz, CLK0=dead?? Given the 45mhz crystal filter, there should then be only 45mhz energy present going
By Jerry Gaffke · #66021 ·
Re: Pseudo-Sine?
to fix this more fully: Switchable filters to replace? the 33mhz? existing one L1-4. for the 3.5- 5mhz range a low pass filter with cutoff of 6mhz for the 7- 10mhz range a low pass filter with
By ajparent1/kb1gmx · #66020 ·
Re: Pseudo-Sine?
Jerry, The problem is the source is square and the DBM is being used for a switch. That means the output is square.? AS to CW it works better than the old pump in a tone and can be clean with the
By ajparent1/kb1gmx · #66019 ·
Re: Pseudo-Sine?
Unfortunately, they went and outlawed spark in 1929.? ? ;-) Jerry
By Jerry Gaffke · #66018 ·
Re: Pseudo-Sine?
I use an old noise generator.? that is a very broadband signalyou can probably tailor it to the HF band73 kd5yyk
By bill wright · #66017 ·
Re: Pseudo-Sine?
I believe Allison has found that the four transmit LPF's are adequate. It is the board routing imposed by using the minimum possible number of relays? that is allowing those harmonics to sneak
By Jerry Gaffke · #66016 ·
Re: Pseudo-Sine?
Most attempts at transmitting CW on *Bitx* variants over the last 15 years have involved? injecting an audio tone into the mike input. Ideally, the result is indeed exactly the same as any other CW
By Jerry Gaffke · #66015 ·
Re: Pseudo-Sine?
When I tested the SSB harmonic performance with a single audio tone, it looked to me like a CW carrier. I also noted that the harmonics were much lower using the full SSB path.? Is a simple solution
By Evan Hand · #66014 ·
Re: Pseudo-Sine?
Ignore that last paragraph of my previous post, included below. It's garbage text.
By Jerry Gaffke · #66013 ·
Re: DC blocking cap between souncard and ubitc mic input. #ft8 #ubitx
The easydigi does have this blocking cap. .1uf Joe KD2NFC
By Joe Puma <kd2nfc@...> · #66012 ·
Re: Pseudo-Sine?
Assuming 16dB gain in the 45mhz amp and a 45mhz signal into the D1,D2 mixer that is at least 10db down from a 7dBm CLK2 local oscillator, the 45mhz square wave coming out of the D3,D4 mixer should
By Jerry Gaffke · #66011 ·
Re: Pseudo-Sine?
Not enough coffee this morning Jerry, However, there is NO way to create a "pseudo sine wave" that will cover that frequency spread (1.8 to 30 MHz) with the current setup and Jerry's right, the only
By Jim Sheldon · #66010 ·
Re: How to connect ubitx microphone jack to soundcard output
The highest value capacitance, the better, I would use either a nonpolarized electrolytic or polyester caps for this audio application. Then a 1:1 dc- isolating audio or data transformer to get rid of
By iz oos · #66009 ·
Re: Pseudo-Sine?
One possibility for CW transmit would be to inject a low level keyed 45mhz square wave at CLK1, the 45mhz crystal filter will turn that into a sine wave. CLK2 can remain a square wave at Transmit_Freq
By Jerry Gaffke · #66008 ·