Menu

Show posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Show posts Menu

Messages - ELK

#1
Quote from: caulktel on August 17, 2018, 10:22:32 AM
Don't know if any of you have been following the debacle going on over at the bitx20.io group regarding the uBitx, but those few fortunate people who have quality Spectrum Analyzers and know how to use them, have found that the uBitx 'mostly' does not pass FCC specs, (US), for spectral purity, (some nasty spurs). Some are advising not to use them on the air until some kind of fix is figured out. Funny I have been using mine every since they came out and nobody has knocked at my door yet, but I don't want them to either. All of the EE's on the group are seeking to redesign the uBitx to meet specs. I find this whole thing to be rather disheartening after all the time and effort I put into my two radios. They are talking about cutting the traces going to the LPF section and adding a daughter board with a new LPF design to fixed the existing boards. Not quite sure what to do but wait and see what everybody comes up with. :( :-[ :-\

Joel
N6ALT

I own a µBitX but I'am not a subscriber of this group. Did they say anything about the frequencies of those spurs ? Are they over 30 MHz  ? In this case, an external third order LPF (at the cost of a few dB of power loss) might do the job...

73's, Stan.
#2
Quote from: caulktel on July 20, 2018, 10:53:01 AM
I ordered another uBitx, it should be here in a few days. It will be the V4 board with some improvements incorporated into the new PCB. I will be using a 3.2 inch Nextion touch screen display on this one.
I'm going to make numerous case improvements to this one, like bolting the finals to the case for better heat dispersion. Gil, you wont like this one because it's going to have a higher idle current draw than the previous one, but it isn't intended for portable use.
I look forward to starting work on it. Ill post my progress.

Joel
N6ALT

Be careful with the finals. If I recall well, the IRF510's back is connected to the drain, which is not "groundable". If you want to bolt them to the case, don't forget to use TO220 insulation kits  ;)


73's, Stan.
#3
Technical Corner / Re: Armored BitX40.
August 09, 2018, 10:24:31 AM
Hi everyone !

I have ordered 2 different kinds of 4x4 and 4x5 membrane matrix keyboards to simulate Gil's military keyboard and work on the corresponding Arduino code.

While waiting for them to come from China (with a bunch of other thingies for my Arduino ecosystem), I am working on adding morse code "talking" capacities to report useful data without any display to the original BitX40 Raduino code.

My main issue is to find enough free pins to connect the keyboard, a buzzer (passive if a pwm pin is available, active if not) for morse rendition and a pin to read battery voltage via a voltage divider (or a specific voltage/current sensor like INA169 and its successors).

I'll get you in touch of my progression...


73! de Stan.