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Re: zBitx Transceiver does it all
Still testing my new zBitx.
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A software update may be necessary to fix CW. ?
I'm not sure the latest updates are finished or well tested for CW. ?So I plan on waiting a bit before I try updating the software. ?
The update process is described in the online zBitx manual, and require connecting the zBitx to the internet. ?The Pi in the zBitx is running standard Raspberry Pi Linux. ?You can log into it and type shell commands.
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Receive on my zBitx seems noisy. ?
There is a pulsing noise from the speaker, even with the antenna disconnected and both IF gain and audio volume turned down halfway.
Transmitter harmonics look OK; but there are some other Tx spurs that need more investigation.
FT8 Rx and Tx both seem to work on my zBitx. ?But I see more FT8 decodes using my HL2 on the same antenna.
The zBitx control UI seems a bit clunky to me (but then again, there are those who don't like the UI of my iPhone apps :-)
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- Ron |
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Re: zBitx Transceiver does it all
Apologies for the cut-and-paste errors in my previous post.
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My zBitx came with 1.0.6.
But I'll probably update soon to get the latest CW latency fixes.
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My first tinySA measurement showed the 1st harmonic is 44 dB down from the carrier.
Thus barely meets FCC regulations ... ?If I measured correctly (though 50 dB of attenuation).
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- Ron |
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Re: zBitx Transceiver does it all
Received my zBitx last night, via DHL.? Powered it up today.? Seems to work. ? https://www.hfsignals.com/index.php/zbitx/ ? About half the price of an Hermes Lite 2, and it includes a Raspberry Pi Zero 2 W running Linux for the radio UI. Also slightly smaller and lighter than my HL2. ? I can ssh into it's Pi Linux, modify and (re)build the software (open source on GitHub). I can also display the UI in a web browser, such as Safari on an iPad (including specrum & waterfall, etc.) So one can run this radio from a colocated iPad via two ethernet adapters (one for the iPad, one for the Pi Zero).? Audio out can be piped over the net, but not microphone input So it can't be used for remote SSB operation. Only keyboard CW and FT8 remote. Half the price of an HL2, and that includes a Raspberry Pi Zero 2 W running Linux for the radio UI. Also slightly smaller and lighter than an HL2. ? I can ssh into it's Pi Linux, modify and (re)build the software (open source on GitHub). I can also display the UI in a web browser, such as Safari on an iPad (including specrum & waterfall, etc.) So one can run this radio from a colocated iPad via two ethernet adapters (one for the iPad, one for the Pi Zero). ? Much easier on the eyes than operating via the small touch display. Audio out can be piped over the net, but not microphone input; so no remote SSB operation. Only keyboard CW and FT8 are remotely operable over the net. ? Includes WiFi capability, a Keyer w/ macros, and FT8 built-in. ? Receiver is a semi-wideband (for the 24 kHz wide spectrum) analog SSB design (which the Pi then further DSP filters for narrower bandwidths). Uses a 24-bit ADC (ENOB is around 15 bits according to Cirrus Logic WM8731 data sheet) in mono mode. Speaker seems decently loud. ? Needs a 9V power supply for 5W. I'm currently running it off of 2 LiFEPo4 18650's at 6.5V, so only at 2W Tx. Or I could use an 8 cell AA holder with 2 dummy cells for about 9V. ? For under $200 (not including any new VAT), vastly better than the uSDX+ V2. ? Ron ? |
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Re: Elecraft AX3 Antenna
No, sorry, a Tarheel.? 5ft whip.? But great location to SW.
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73, Eric NF6S ex WD6DBM ?
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Re: Elecraft AX3 Antenna
I like the AX1, and bought an AX2 with the intent to modify it, but that hasn't worked out.? The AX3 should work well from secret location #2 in chester, where I have worked tuvalu on 15 cw.??
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73, Eric NF6S ex WD6DBM ?
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Re: Elecraft AX3 Antenna
It's free standing, and breaks down to 6" pieces.
If coat pocket sized and free standing are your requirements, What's the competition?
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Maybe the eBay $20 to $40 5MHz-55MHz Mini QRP Shortwave Antenna with Tuner Adapter?
And that still needs a mounting bracket and tripod or base of some sort.
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Ron |
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Re: Elecraft AX3 Antenna
Shocking nobody, that would be me.
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73, Eric NF6S ex WD6DBM ?
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Elecraft AX3 Antenna
Elecraft has just announced the AX3 antenna.? 6 bands, 30, 20, 17, 15, 12 & 10m.? You have to have a tuner to use it.? It comes with a very small tripod (3 rods fit in 3d printed base of antenna.? Cost 274 dollars.? Yes, that is correct.? ?It can be seen on their website.? ?I am interested in others opinions of it and if anyone is going to buy one.
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Doug |
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Fw: [FARS-Announce] FARS March Meeting - Tonight!
Fact Checking: The active cascode amplifier was invented in 1979 and included in Analysis and Design of Analog Integrated Circuits, first edition 2001. They are a refinement of the cascode amplifier which goes back to vacuum tubes. I back in the day, I used discrete transistors for amps into 10's of MHz. The abstract to Ed's talk said they were what made the NanoVNA and TinySA possible. These devices use direct conversion. No amplifier on the front end. Yes, they have mixers and switches for the input circuits. The enabling hardware for these amazing devices is mostly the digital chips and a display that can all be powered by a battery.
That said, these hand held devices are can be really handy.
----- Forwarded Message ----- From: Steve Stearns via FARS-Announce <fars-announce@...> To: 'FARS Announce' <fars-announce@...> Sent: Friday, March 28, 2025 at 11:08:13 AM PDT Subject: [FARS-Announce] FARS March Meeting - Tonight! Foothills Amateur Radio Society Membership Meeting on Friday March 28 ... Presentation:? Broadband (4 GHz) Precision Amplifiers ? Summary:? We are now all familiar with the NanoVNA and the Tiny SA.? There are also numerous digital scopes now that are very affordable.? An example is the DSO03D12 -? a dual trace color portable oscilloscope with probes that easily measures in real time up to 150 MHz.?? This instrument also has built in DVM and signal generator ¨C all for less than $150.? These instruments would have cost in the thousands of dollars 10 years ago. ?Only the most serious hams own expensive HP or Tektronix equipment?? So why are they now all so affordable??? The simple answer is an innovative operational amplifier (¡°op amp¡±) design.? For the last 50 years, op amp design followed a tried-and-true formula that did not change.? Dave Fullagar designed the uA 741 in 1968. ?It had unity gain bandwidth of 1.5 MHz.? True, small incremental improvements happened over the years, such as current mode feedback.?? However, these were evolutionary, not revolutionary.? Steady improvement in semiconductor processing gave incremental gains in frequency response (10¡¯s of MHz at most). ?However, in the early 2000¡¯s a new amplifier topology was invented that allowed controlled high precision feedback gains in the 4-6 GHz range.? This configuration is only now finding its way into amplifier text books.? Ed will explain this new circuit configuration and how it works. ? About the Speaker:? Ed Fong, WB6IQN, teaches RF Wireless Communications and I/O Design Fundamentals for UC Santa Cruz in Silicon Valley. He taught RF Wireless at UC Berkeley from 1998 to 2011.? Ed is the owner of Ed¡¯s Antennas . ?Ed¡¯s DBJ-1, DBJ-2, and TBJ-1, dual- and tri-band antennas are popular with hams, commercial and government users, and were featured in magazine articles in QST (February 2003, March 2007, and March 2017) and CQ (Summer 2012), and reprinted in three ARRL books:? VHF/UHF Antenna Classics (2003), Antenna Compendium Volume 8 (2010), and Portable Antenna Classics (2015).? Ed¡¯s past presentations to FARS include the uSDX+ portable HF transceiver (November 2023), phase-locked loops (August 2023), single-sideband modulation (January 2023), ground-independent vertical antennas (August 2019), and DMR radio (April 2018). |
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Does anyone have Eric's email address?
Does anyone have Eric's email address or Eric, if you are reading would you please email me at doghouse3@...??
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Thanks, Joy |
David