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Re: #ubitx #ubitx-help
#ubitx-help
#ubitx
Tell that to varidur.? Reverse protection diodes are cheap insurance.
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Re: Mic doesn't work in bitx40
#bitx40
Thanks for your reply.. I've already swap the leads of the electret mic. But the same thing is happened. What voltage suppose the capacitor showed exactly? |
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Knob adapter sleeve (6mm ID, 1/4 inch OD)
I got a bit frustrated finding a knob to fit the 6mm knobs on the uBitx.? Fortunately I found these adapter sleeves to bring the shaft OD up to 1/4 inch so I can use standard American 1/4 shaft knobs!??? I received them today and they work.? You do have to be careful to pull them out slightly before you tighten the set screws so the knob has enough clearance to be pushed in for the switch to work.
https://www.ebay.com/itm/222983860788 -Jonathan |
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Re: #ubitx #ubitx-help
#ubitx-help
#ubitx
This reference suggests silicon diodes generally fail with a short when subjected to over-voltage.
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And generally fail with an open when subjected to too much current. ? ?? The uBitx reverse protection diode would likely blow open due to excessive current (and heat) if the power supply is not fused properly. Jerry On Mon, May 21, 2018 at 08:50 pm, WA9PWR wrote:
Generally silicon diodes will fail with a short circuit, protecting the hardware. |
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Re: #ubitx #ubitx-help
#ubitx-help
#ubitx
Generally silicon diodes will fail with a short circuit, protecting the hardware.
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Re: boosting the power on 28 MHz
#ubitx
I just want to say that I'm very happy to see you take this on!
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Jerry On Mon, May 21, 2018 at 07:30 pm, ajparent1/KB1GMX wrote:
yes and other mods as well.? For now its at best a partial fix. |
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Re: W8TEE vft/tft questions
Jack Purdum
Tom: If we are talking about the VFO/TFT board, look for the place where we read the encoder. If this is the BITX code, look for the symbolic constant ENCODERTUNING around line 1720. At line 1729, you should see some scaffolding code: #ifdef DEBUG???????? ?
Serial.print("Examine Fast Tune: Start = ");??????? // May be useful for setting Fast Tune rate Serial.print(fasttuneStart); Serial.print("?? end = "); Serial.print(fasttuneEnd); Serial.print("? diff = "); Serial.println(fasttuneEnd - fasttuneStart); #endif??????? ? If DEBUG is defined (see line 36) it will print the info out. (If it's commented out with "//", remove those.) This should tell you if the encoder is working and if the Fasttune parts are working. Jack, W8TEE
On Monday, May 21, 2018, 5:09:08 PM EDT, tom.mccobb@... <tom.mccobb@...> wrote:
I completed? a build of Jack's board a few months ago, and it was working fine. I even made some mods to his code, adding a 4th button press destination from which I could set tuner increments to 50Hz, 100Hz, 1KHz.? (I never had much luck with the encoder speed routines) All was fine until just recently.? Now when I rotate the encoder, It will pretty much stay in the the same 2KHz range.? If I spin it furiously, I can get it to move erratically up and down the band, but I have obviously broken something. Which isn't a complete surprise given how many times I have dismantled the unit to change my front panel layout, swap in a SO-359 for the standard antenna jack, replaced the power connector on the W8TEE board to a screw terminal, etc.? I suspect I laid the VFO down on the metal case with some pins touching where they shouldn't have. So the? question is where to look.? I have checked and verified voltages.? I backed out my modified sketch and reinstalled the original.? I have swapped in several different encoders (I got a bunch of them).? No joy.? The behavior is the same whether it is driven by the USB power connector when disconnected from the Bit40, or the Bit40 power.? (I am feeding it 12v, btw, as the schematic specifies, not the 7-9v in the assembly guide. Is that a problem?).? In all other respects it appears to work - I think - see below.? I have a spare Mega 2560, and as soon as can get headers on it I will swap that in.?? While troubleshooting, I put the outputs on a scope.? The buffered output looks to be about 2.5-3v , and is a nice clean sine wave at about 60 Hz - and it does not change when the encoder is rotated.? The un-buffered output is about the same frequency, but voltage is several orders of magnitude smaller.? And the square wave output is just noise, or at best a very noisy triangle wave.? Does this indicate a problem with the A9850?? (Yes, it could indicate that I don't know what I am doing with the scope, a Tek 2235). Any pointers?? It is kind of fun troubleshooting, but I would like to get it working again before the end of the decade. Thanks. |
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Re: Socketing a Nano to the other side of the Raduino
Cuz sheet metal work is not as much fun as burning solder.
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Shielding various sections of the radio from each other is not a bad idea. And the Raduino/display is a good place to start. Allowing the Si5351 clocks out of the box while disallowing everything else might be problematic. Simple solution: move the Si5351 to the uBitx, filter the i2c bus to a few hundred khz and less. Though I do think that running the processor from the BFO and kicking? the USB-to-UART out entirely would pretty well solve most interference from the Raduino.?? Jerry On Mon, May 21, 2018 at 07:23 pm, ajparent1/KB1GMX wrote: Why not remote it some from the mainboard and put a box around the back of it |
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Re: boosting the power on 28 MHz
#ubitx
yes and other mods as well.? For now its at best a partial fix.
FYI the IRF510s will deliver 10W and then some at 10M! Allison |
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Re: Socketing a Nano to the other side of the Raduino
Why not remote it some from the mainboard and put a box around the back of it
with the wires sneaking out of? it.? The front of the box is the front panel and the Raduino is tinned up.? Take care with the signal leads (use SHORT twisted pairs). Used those tricks for old style counter circuits that radiated digital noise like mad. In my case the height of the board when mounted is a problem.? Solution is change the board connector into a right angle and then relocate the display with wires. That lowers the profile.? ?Both boards can easily then have a cover over them made of soldered up PCB, hobby brass, or copper screening.? Control pins will exit though the screen box via 1000pf feedthroughs.? I try to keep noise in the box so to speak. Allison |
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Re: Transmitter Mods
¿ªÔÆÌåÓýJust to let those know that sent me
prepaid envelopes, I was away for the last 2 weeks, and will send
out the parts tomorrow for the requests that I received during my
absence.
Howard On 4/17/2018 11:25 AM, Howard Fidel wrote:
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Re: Anyone working With Nextion HMI LCD Touch Displays and UBITX?
Haven't tried that specific one but I have an Rpi with a 7" TFT with touch.? Power required i
s about that of the Rpi.? But it looks good and is really nice to use. However using it with a Raduino is likely a bit tough as its compute intensive and IO too. STMF4 or Cypress CY8CKit-049-42xx. The Cypress family is handy as its PSoC peripherals allow some programable CLBs for custom interfaces.? That and 32 bit ARM at 40Mhz 32k falsh and 4K ram (plus ADC, serial, lots of IO) makes a nice step up. Allison |
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Socketing a Nano to the other side of the Raduino
We would like to socket the Nano, but then the standard display doesn't fit,
If we extend the pins to make it fit, then we may have to redo our enclosure to give the display some extra room. Here's a possible solution: Remove Nano from the Raduino, add socket strips to the other side of the Raduino, Get a Nano with the pins not yet installed: ? ?? Solder them pins to the top side of the Nano. Plug and play. Bad news is that the Nano is now sitting right above the RF part of the uBitx, no longer shielded by the Raduino's ground plane. So the audio tone issue could be the next issue to solve. Fortunately, the CH340 is now easy to remove/disable, use a USB-to-UART cable assembly instead. Perhaps hang caps on the 16mhz resonator to bring it down in frequency, or replace it with a non-16mhz crystal?? Drive it from the BFO? Or tinfoil and duct tape? Jerry, KE7ER |
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Re: RF power chain mods and improvements..
Here is where i'm at...
This is experiments 101, interim progress. While waiting for parts, used whats on hand: Made Q90 a 2n2369A smt part, Better gain bandwith product (ft) gain maintains at higher frequency (also lowered bias) I installed 6 2n2222A in the predriver and driver.? (HFE hold up at high current( Put 470 pf across R82 ( gain increases with frequency. Placed 390pf cap from top of RV1 to the wiper? (only works if your not maxed out!) ? ?The trick here is couple more rf through RV1 with increasing frequency.? If it is all the ? ?way up its hard to get more vis this path. Put 3.3uH inductor in series with R86 (allows decreasing feedback with frequency) Turned up the bias on the IRF510s. I'm running at 210ma per device!?? Doing this really helped the output power at 20M and up. Key down at 10W is 2A. Power set to 10W at 12.0 V 3.6mhz 40m? ? 10.3w 30M? ? 6W? ???? output low pass filter?? 20m? ? ?9.8w 17M? ? ?7.5w ???? low pass filter again?? 15M? ? ? 8w 12M? ? ? 8.5W 10M? ? ? 8W? ? ? ? ? This is still interim testing and I have many more things to try. It does confirm that the performance can be more uniform. I'm perplexed that 30M and 17M is so low, it may be the low pass filter in use. The only problem I see with 210ma per device is the no-modulation standing current is .8A which is not battery friendly but maybe what we need.? They do not seen to heat much.? It suggests T11 is less?than optimum. I need to try improved output transformer both 1:1 (2t:2t) and 1:2 (2t:3T) on bn43-6802 (and bn61-6802).? I may also try a different configuration driver transformer. This IS NOT FINAL, net even close. I need to see what it looks like with spectrum analyzer.? The final result will be put up with pictures and explanation of what, where, and how. Patience please. Allison |
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Re: Anyone working With Nextion HMI LCD Touch Displays and UBITX?
Thanks! Joe VE1BWV On Mon, May 21, 2018 at 10:35 PM, Doug W <dougwilner@...> wrote: There was a thread a few months back... |
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Anyone working With Nextion HMI LCD Touch Displays and UBITX?
Hi, With the current nano as the processor it does not take much to bog it down so using Nextion? Touch displays would provide much improved visual enhancements Free software is available? to build your graphic display, and emulate functions before uploading to the Display... |
Jonathan