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Re: Who has AGC... Fun Facts
Jerry Gaffke
You don't have to be a dinosaur.
toggle quoted messageShow quoted text
IF derived is better because it comes on faster, it would take milliseconds to sense low frequency audio, and in that time the RF/IF stages will go into overload and distort. So we have audio derived AGC and RF derived AGC (that is where the signal level is detected), and while most radios then adjust the RF and/or IF gain accordingly, we could also adjust the AF gain. We might need 3 or 4 different acronyms. ;-)
On Sat, Apr 20, 2019 at 11:06 AM, Scott McDonald wrote: And because I’m a dinosaur I want to believe a decent IF-derived system is better, though I have to admit the ubitx audio-derived stuff is pretty good. :)
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Re: More Nextion 3.5" tweaks to do
Joe Puma
Thanks Sam, I will give it another look. There is where i was adjusting the lines for vertical positioning I believe, Its hard to run a test to check if you properly stretched the graph unless you put the code in your Nextion. The simulation mode goes not give you data for the graph. I see Nextion editor has a generator, I was thinking that maybe its signal generator so you can simulate a signal for the graph.
toggle quoted messageShow quoted text
Joe KD2NFC
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Unboxing #ubitx v5
#ubitx
Ron Stauffer
I created a short unboxing video of the uBitx v5 and I put it on my maker blog at hamradiomaker.com
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Re: Who has AGC... Fun Facts
Adrian Chadd
A decent IF system would be great if we did AM/FM, right? :) But it's OK how it is! -a
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Ubitx tx/rx "chatter" (read old thread)
Hi all! I have just connected a bc645 4 pin electret mic to my ubitx and am getting a 5 tx/rx "chatter" on transmit on a dummy load, when press ptt. When i release, all is fine, rx is lit and i hear rcv audio. As a test, i enabled tx stop on the cec software, and pressed ptt. The tx indicator lights red for as long as i hold ptt, and then returns green as I unkey. This seems to indicate the ptt works as intended. After unselecting tx stop, the chatter returned. What am I missing? ...continuing to read thread...
73, Kelly K5AID
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Re: Ubitx tx/rx "chatter" (read old thread)
Arv Evans
Possibly you have connected the audio lead to the PTT circuit and the rig is being keyed by audio. Possibly you are getting RF into the PTT line (long curly cords are problematic). _._
On Sat, Apr 20, 2019 at 2:35 PM Kelly Mabry <kmabry2007@...> wrote: Hi all! I have just connected a bc645 4 pin electret mic to my ubitx and am getting a 5 tx/rx "chatter" on transmit on a dummy load, when press ptt. When i release, all is fine, rx is lit and i hear rcv audio. As a test, i enabled tx stop on the cec software, and pressed ptt. The tx indicator lights red for as long as i hold ptt, and then returns green as I unkey. This seems to indicate the ptt works as intended. After unselecting tx stop, the chatter returned. What am I missing? ...continuing to read thread...
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Re: More Nextion 3.5" tweaks to do
Sam,
"subtract existing controls"..... Please explain, as I'm willing to dive into it and try. I've attached my latest tweaks though I'm not at all ready to post it until I check it out in the field and get the graphs right. 73, Ted
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Audio AVC
Jim Tibbits
what with all the fond philosophing and theorizing and debating about avc vs.agc ..behold a REAL circuit ..
found this in an old magazine ... Modded it to look like this And included measurements ...something I have not seen on a lot of the others ... No phase shifters (feedback is DC) so I doubt it will oscillate too much ...works...keeps my ears calm AGC/AVC is a complex problem....Simple solutions to complex problems seldom yield positive results Jim
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Re: Remote Head?
Dexter N Muir
Great stuff, Ted! VGA cable? hadn't thought of that! :) in true AmateurLogic(.TV) fashion: Cheap-old-man compliant!
73 de ZL2DEX
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Re: Audio AVC
Jack Brabham - KZ5A
Looks like a simple solution to a complex problem.
73 Jack KZ5A
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Re: Remote Head?
Dexter N Muir
As an ex-workmate put it (in false Irish brogue): "Good t'inkin', O'Rourke ... yer foired!" :) 73 de ZL2DEX
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Re: Ubitx tx/rx "chatter" (read old thread)
Evan Hand
That seems to be a common problem depending on antenna and antenna connections. I had similar issues with an off center fed dipole and RF on the coax braid. Fixed it with snap on ferrites on the coax, others have used blocking baluns. Also a .o1 to .1 mf cap on the PTT line to ground has been listed as helping.
the above are my experiences and thoughts, YMV 73 Evan AC9TU
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Re: Ubitx tx/rx "chatter" (read old thread)
Here is what I am using as a wiring guide. Specifically the 4 pin connector is the black as audio, brown as ptt and red as ground. Coming from the front left audio board, J6. (Sunil kit)
Kelly K5AID
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Re: Ubitx tx/rx "chatter" (read old thread)
Hi Kelly,
Looks like you should have Pin1 on the new mic going to the red wire connection on the 3-pin board connector. Also you should have Pin2 on the new mic going to the black wire connection and Pin3 going to the brown wire connection (and no connection to Pin4). Is this the way you have it? 73, Mark
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Re: Ubitx tx/rx "chatter" (read old thread)
Not even close... doh... so embarrassing this is...
Will fix and retry... Kelly K5AID
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Bitx 40
Earl Warhus
I would like to know if the brown wire from Raduino should be grounded? Thanks Earl Ve1awc
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Re: Ubitx tx/rx "chatter" (read old thread)
Update: chatter gone! I wired it as Mark directed, and it doesnt chatter!
73 & thanks! Kelly K5AID
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Re: Audio AVC
Meets my criteria for a mod (1) works (2) minimally invasive (3) dirt cheap, easily obtainable parts (4) easy to remove (when it don't work) Jim
On Saturday, April 20, 2019, 11:43:06 PM UTC, Jack Brabham - KZ5A <kz5a@...> wrote:
Looks like a simple solution to a complex problem. 73 Jack KZ5A
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Re: uBitX PTT cycling
MVS Sarma
Hi Kelley, Try to place on 1000pf (1nf) capacitor across the electret mic. Things should improve. All the best. Regards Sarma vu3zmv
On Sun, 21 Apr 2019, 12:27 am Kelly Mabry <kmabry2007@... wrote: Hi all! I have just connected a bc645 4 pin electret mic to my ubitx and am getting a 5 tx/rx "chatter" on transmit on a dummy load, when press ptt. When i release, all is fine, rx is lit and i hear rcv audio. As a test, i enabled tx stop on the cec software, and pressed ptt. The tx indicator lights red for as long as i hold ptt, and then returns green as I unkey. This seems to indicate the ptt works as intended. After unselecting tx stop, the chatter returned. What am I missing? ...continuing to read thread...
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Re: uBitX PTT cycling
MVS Sarma
Congrats Kelley, you solved it.
On Sun, 21 Apr 2019, 8:39 am MVS Sarma via Groups.Io <mvssarma=gmail.com@groups.io wrote:
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