Different co-ax only matters if it's part of the radiating antenna. Feedline (e.g. to tuner or other matching network) not so much. Once the antenna gets close enough to resistive at whichever value, it matters little. If you have co-ax coming out your ears, it's handy as part of a dipole - broadens the resonant range.
73 de ZL2DEX

Then of course there's using the existing circuit with a couple more diodes in the base circuit to drive power transistors Darlington-fashion with emitter resistors of 0.05 ohms - and a duplicate circuit driven anti-phase? to the 'earthy' side of the speaker. Real advanced, but totally basic - and all from the junk-pile! Go burst your eardrums with Hi-Fi at your leisure!
<sarcasm off>

That's perfect thank you. I'm not going into the 50 Vs 75 ohm debate other than to say that I am using 75 cable with an impedance transformer on my current rig. Works exceptionally well with an SWR of 1.2 on a home brew slim Jim on 2m. I get 75 ohm cable for free before anyone starts accusing lol.

That's possibly not going to work with HF variance of wavelengths, so I'm either going to have to pay for cable or come up with something else ?

and basic audio-amp practice: measure that standing current by the voltage across either or both emitter resistors. Report your finding of the V or I for cleanest audio here and a consensus will quickly be shown that can quickly be set in any rig - maybe with that preset measured could indicate a default value that can be pre-installed (factory mod?). It may vary per speaker impedance / ouput transistor type / emitter resistors value, giving more audio to taste. Honestly, has no-one any audio experience? That basic circuit is infinitely extensible!
73 de ZL2DEX

If this is about uBitx V4 then you need to do the audio mod. Some boards may be overly distorted!

Cut the track between D15 and D16 and solder the center and one end lead of a 100 Ohm preset.
I use a bourne10 turn.

Set the trimmer to 0 ohm and switch on. Now slowly increase preset till distortion vanishes and the
audio volume will increase. This should happen about mid point. Do not advance it too much as you
will have hot output transistors.

Raj

I went with BNC because that's what is on the end of my buddy-pole coax.
--
Lee - N9LO? "I Void Warranties"

?

Hello.

I'm building a Bitx40 (v3 board) in an Amateurradiokits.in Universal Blue II case.? I'd like to use a Baofeng Mic with this build.? I have a couple of questions.

Question 1:
The Baofeng mic connector has 2.5 and a 3.5 mm connectors on it, the Bitx40 and case kit both came only with 3.5 mm jacks.? I bought a 2.5mm jack but it's to small for the mounting hole on the case.? Is there some place to get a 2.5mm jack which fits in a 3.5 mm mounting hole?? The case was advertised as having the connector mounting spacing to accommodate a Baofeng mic, but I don't see how it's supposed to work with the mounting hole sizes provided.

Question 2:
The Sleeves on the mic and speaker jacks will make contact with the metal case.? Is that a concern at all?

Question 3:
Based on the answer to question 1 I may decide to modified the Baofeng mic using the method described by John McGrath (KF6EFG) found here.



This means I won't be using the speaker in the Baofeng at all.? I'm fine with this.? One question though.? Can the Mic and PTT GND be common so I can use a single 3.5mm stereo jack (tip, ring and sleeve)?? Also same question as before, is it a concern if the sleeve is shorted to the case?

Craig (VE6TBW)

SMA's are ideal, use one of those if you have them.
Good to several ghz.
Not that impedance control matters much at HF, as evidenced by the the lack
of coax between antenna connector and uBitx main board.
Many qrp rigs use RCA phono plug connectors, designed for audio, not impedance controlled.

The machining on some of the BNC's provided with the uBitx kit is not up to par,
the pin of the mating BNC connector on your cable may not make sufficient contact.?
No, this is not a 50 vs 75 ohm connector issue, the provided connectors are 50 ohms.
And 75 ohm BNC connectors would mate just fine with 50 ohm BNC connectors anyway.

Some ham gear manufacturer decided to use SO239's back about 1930, and it became the standard.
Since it's the standard, nobody can sell a commercial medium or high power transceiver these days
without an SO239 on it, or they'd be deluged with calls asking how to hook it up to the PL259
on the antenna cable that's been coming in through the window these last 90 years.
But at HF frequencies, could use just about any connector that ohms out ok.?

Jerry

Oh yea. That Nextion will do fine if you use Rich Neese's?



TFT or Hmi's


--
N5KBP

Purest will tell you that the BNC is superior to the SO239 but at HF it's not that big a deal. Use whatever you have. The SMA's will do fine. I use the SO239 simply because all my jumpers on my HF antenna system are PL259's.
--
N5KBP

The terms firmware and software are interchangeable in this scenario. The difference in a hex file and a ino file is that a hex file is machine readable and an ino is human readable. When? you write code it is called source file. This is the ino. The arduino IDE compiles or converts this human readable file to a hex file the arduino can read and follow. It hen uploads the hex file to the arduino. The hex file That Dr. Lee distributes is nothing more than the ino file he has already compiled for you. I prefer the ino file myself. It gives you the flexibility to change things if you wish. ie make it use the i2c dsp meter, drop unused functions to free up memory etc.
--
N5KBP

Hi group,
I successfully added Nextion 2.4 screen to my uBit-x? using Dr. Lees? CEC software/firmware? version 1.097 (currently 1.1)'
I have had a lot of fun learning how to use it,? but still confused about the update process
Dr. Lee talks about 2 methods of uploading changes.? 1) upload the arduino code directly to the radino, or 2)? Save the arduino code as a hex file and use the bootloader to load the hex file.
When I first set this up, I followed Dr Lee's instructions? on uploading the hex files and was successful.? Dr Lee seems to prefer this method as he goes into great detail on how to do it..
My question is, am I getting confused between firmware and software, are the two methods the same, or will everything be accomplished by uploading the latest? ino file.
Thanks,
Andy KM4TRT

So I just got my uBITX last week, and am looking at the antenna connector.

Now, I am VERY new to all this, so be kind.? I would like to keep all my gear standardised from this point on.? Now I appreciate that BNC and SO239 are commonly used, however, is there any advantage to one over the other?? I have a load of chassis mount SMA connectors... any reason to not use these?

I have been looking at ? Is that the right one (spending the extra quids on getting the enhanced version)??

Hi

THX. Because i will use stock volume control delivered with uBitx, I will disconnect VOL_MID from volume control? and connect it to IN from external amp.

Martin, OK5MCA

TSW (Triumvirate Skonk Worx, ) has just released an incremental "Bug Fix" version of our 2.8" color TFT Touch screen software which allows touch control, keyboard control and now MOUSE control of the uBITX radio.?

Before you even ask, the 2.8" screen is NOT a Nextion, it's a fair bit cheaper than a Nextion it works only with our BITeensio card which uses a Teensy 3.6 MPU. The BITeensio card, since it uses the far more powerful Teensy 3.6 for the MPU, was not designed for and will not run with the CEC software.

The BITeensio and TSW's software for it runs stand-alone and does not need an external memory manager to change or update any of the user's parameters without having to connect to a computer to do so.? The only two reasons to even hook a computer to the uBITX running with our BITeensio MPU system is to update the firmware or to use the W2CTX remote control program (RCP) to remotely control the uBITX.?

The full source code, operating instructions and current information for this software can be downloaded from the files section (easily accessible from the main page by following the links) of the website.? I've even created a couple of videos outlining the 2.8" screen with our new "mouse control" firmware? that you can view from the website.? They are works in progress and I am not a professional videographer so there are bloops and a mistake or two as well, but the do show a good bit of what the BITeensio with the 2.8" display can do to control the uBITX.

All of our earlier firmware for the original Raduino and any of our newer cards is downloadable from the same website's links to our "files" section.?

BITeensio uBITX controller cards are available in kit form and ordering information is located on the website.? This kit is not really for beginners though it isn't all that difficult to assemble with care and by following the explicit directions in the construction manual.? By the way, all documentation for everything TSW has done for the uBITX is available in PDF format for download in the "documentation" directory of the files section on our website.

Jim Sheldon, W0EB
TSW Project Coordinator/Manager

开云体育

Terry that’s about my style also! ?At least until I get everything fixed up. ?Makes it easy to get it to work on new ideas.?

Just wire in a separate 12 volt relay of your wanting , And power it from the same transmit line voltage that the transmit relay is powered from on the main PCB ....? Job done?

i use a wooden base board about half an inch thick with aluminium from and back panels screwed to the edge. looks ugly but costs next to nothing

terry gm4dso

That’s great thank you. I will try that.?

Regards Carl.