Date   
Re: latest ubitx manger ??

Kevin Rea
 

thank you !!!

Re: VK3YE AGC pcb.

Nick VK4PP
 

Hi Richard.
I did make it a bit smaller, but only by standing the resistors and diode on-end.
I agree, SMD is do-able, I have the Kees AGC, but TH is easier on the eyes and less tiring, I also just like the look of TH components too.



I might be able to do a board that you can use either/or if you so choose...Hmm...

I have been thinking deep in my mind about putting all these boards I have done into a single one, as well as a complete TH ubitx board.
Maybe in a modular stacked version... But right now I'm a bit time poor...

73 Nick VK4PLN

Re: End Fed antennas w/ uBITX #ubitx

Warren Allgyer <allgyer@...>
 

Jerry

As I have said, it depends upon your definition of “work”. 

Using your 10 watt transceiver with this antenna is the same as using a 1 watt transceiver with a resonant half wave fed by a tuner or low loss transformer. I have made worldwide contacts using 1 watt. 

I just want want people to understand that they can do much better for a lot less money if they understand what is actually happening with their antenna. 

Almost any antenna will “work”. “Working well” can be easily achieved with a little bit of effort and our collective knowledge level can be improved at the same time. 

WA8TOD

Re: End Fed antennas w/ uBITX #ubitx

Jerry Gaffke
 

Warren,

If you have a lossy transformer, it's not working like it should.
For whatever reason.

You are digging into this, making measurements, more than most folks do.
That's good.
But there are multiband EFHW antennas that work well.

Jerry


On Wed, Jul 25, 2018 at 04:22 PM, Warren Allgyer wrote:
The number is out of context. This was actual VSWR of the wire itself measured with an impedance bridge referenced to 2500 ohms. On the input side of the transformer the measured VSWR was under 2:1 in all cases due, as previously discussed, to the lossy transformer. 

Re: End Fed antennas w/ uBITX #ubitx

Warren Allgyer <allgyer@...>
 

Jerry

The number is out of context. This was actual VSWR of the wire itself measured with an impedance bridge referenced to 2500 ohms. On the input side of the transformer the measured VSWR was under 2:1 in all cases due, as previously discussed, to the lossy transformer. 

WA8TOD

WA8TOD

Re: VK3YE AGC pcb.

Richard Spohn
 

Regarding the VK3YE...don't make it smaller. I like Kees' AGC kit but
I choked on getting it because I have never worked on SMT boards and
just thinking about doing so makes me tired. Having a through-hole
AGC kit is something I am interested in. Don't make it smaller. -
Rich WB2GXM

On 7/25/18, Mvs Sarma <mvssarma@...> wrote:
Nice . I suppose we could try to make it smaller

regards
sarma
vu3zmv

Regards
MVS Sarma


On Wed, Jul 25, 2018 at 9:43 AM, Nick VK4PLN <nickpullen@...> wrote:

Something I'm Working on...




73 Nick VK4PLN




Re: End Fed antennas w/ uBITX #ubitx

Jerry Gaffke
 

Judging from the VSWR figures for the EFHW, it's not working like it should.
For whatever reason.

It looks simple.
But the chatter in that facebook page suggests a homebrew multiband EFHW is tough to get right. 

Jerry



On Wed, Jul 25, 2018 at 03:21 PM, Warren Allgyer wrote:
I have designed an experiment to quantify the relative skywave performance of two HF antennas. I use the reporting capabilities of WSPR as the data collection. I built an A/B antenna switcher that synchronized with the two minute WSPR cycles and selects the alternate antenna each successive cycle. 
 
A test run is normally done to collect at least 500 spots. That data is downloaded into an Excel database and the parsed by antenna and reporting callsign. Call signs that are reported on only one antenna are excluded. I then compute the average reported S/N margin for each callsign and aggregate those averages by antenna. It sounds complicated but once the model is set up the process of inputting a set of data and analyzing only takes a few minutes. 
 
Here is an example that compares an EFHW 40 meter using the subject transformer with my 230 foot open wire fed doublet. 
 

Re: latest ubitx manger ??

 

latest ubitx manger ??

Kevin Rea
 

hi guys,
After getting my stock ubitx working, i am ready to install my Nextion 3.2" enhanced screen.

what is the latest version of ubitx manager and where do i download it from ?
i found a version: 1.081, but it cannot read from my stock ubitx board.
I have the power off, i think that is how you are supposed to do it, I connected the usb cable to my pc and in my device manger
it reads the port as:  USB-SERIAL CH340 (COM8)
so i went into its settings and made sure it was 38400, None, 8, One,
that is what the ubitx manager is also set on.
In ubitx manager i clicked on the button on the top of the screen, 'Open'   after a few seconds that button turns to 'Port Close',
so i am assuming they are talking to each other..
I then hit the button - 'Read from uBITX' and after a few seconds I get this read error at the bottom of the screen- ' Error Receive Length = 1/1027'

any ideas folks ?

thanks for any help.
kevin rea
lancaster, calif.
k6rea

Re: Replacement audio amplifier?

 

Sorry, I forgot to mention, I was referring to the Banggood amps and others like them. The LM386 amps would be a better choice but a bit noisy.

Joel
N6ALT

Re: Replacement audio amplifier?

 

I would be a little Leary of using these in a HF transceiver as they are class D amplifiers and most probably would cause interference on the ham bans when receiving. I have various 'Boom Cubes' that use these type of amps in them and work great for audio amps but when they start working hard a band of noise shows up on the 40 meter spectrum and its very ugly moving all over the place.

Joel
N6ALT

Re: Replacement audio amplifier?

Nick VK4PP
 

There are complete LM386 amp boards for $1 on ebay. I bought 5 just because, yet to test one though....
LM386 Audio Amplifier Module 200 Times Input 10K Adjustable Resistance
73 Nick VK4PLN

Re: End Fed antennas w/ uBITX #ubitx

Warren Allgyer <allgyer@...>
 

Hi Allison 
 
I have designed an experiment to quantify the relative skywave performance of two HF antennas. I use the reporting capabilities of WSPR as the data collection. I built an A/B antenna switcher that synchronized with the two minute WSPR cycles and selects the alternate antenna each successive cycle. 
 
A test run is normally done to collect at least 500 spots. That data is downloaded into an Excel database and the parsed by antenna and reporting callsign. Call signs that are reported on only one antenna are excluded. I then compute the average reported S/N margin for each callsign and aggregate those averages by antenna. It sounds complicated but once the model is set up the process of inputting a set of data and analyzing only takes a few minutes. 
 
Here is an example that compares an EFHW 40 meter using the subject transformer with my 230 foot open wire fed doublet. 
 
 
WA8TOD
 


Re: Replacement audio amplifier?

Robert Ogburn
 

Consider this for general use audio amp.

https://www.banggood.com/10Pcs-XPT8871-5V-5W-1A-Single-Channel-Mono-Digital-Audio-Amplifier-Board-p-1268826.html?rmmds=detail-left-viewhistory__3&stayold=1&cur_warehouse=CN  

 

5W  5V  digital mono. uses the XPT8871 IC (SIMILAR TO LM4871).

Amp has typical 3dB point of ~350 Hz and ~90kHz..  suitable for voice.

 

 10 assembled amps from Banggood for $5.31 USD shipping included.

uBitx went POP. now very thing Audio and High SWR on TX.

Nick VK4PP
 

Well, what a night, just as I was finishing off the last bit of work on the radio, a new battery pack and fuses and connectors.

I decided, whilst I was listening to the radio, to switch over to the new battery. Now I did not use the off switch, just unplugged the Anderson from one battery and into the other.

POP, on it came, but the receive audio had changed. It had lost all of its punch, very empty and tinny, almost like i was running a 1khz filter or something.
I tried the TX and the power needle just straight to max and a high SWR too, that's with out speaking into the mic.

Strangely, it appears that CW TX is not effected... So?

So my initial thoughts are that I have jut blow the speaker? Nope, the TX is affected too...

Now I am thinking I have blown some of the front end mixer transistors... I know CW works different to SSB with regards to the mixers and such, ill look into that today and get a better understanding of what can be happening?

Radio still tunes and is on frequency, Just terrible thin RX audio and massive TX feedback/SWR.

Any thoughts?

Thanks and 73, Nick VK4PLN

Re: VK3YE AGC pcb.

Nick VK4PP
 

EasyEDA.com.

Re: End Fed antennas w/ uBITX #ubitx

Warren Allgyer <allgyer@...>
 

To wit:

Re: End Fed antennas w/ uBITX #ubitx

Warren Allgyer <allgyer@...>
 

I am actually in Ulaanbaatar at the moment. I have my brand new uBITX , built into  9 x 18 x 3 inch pistol case, along with a 12v SLA, charger, mic, paddles , speaker, the aforesaid 14:2 binocular transformer, and a resonant 40 m EFHW hanging out the window of a sixth floor apartment. I am also the proud owner of multiple airline inspection notices left in the case as they tried to figure out what I was packing on the way over. I did enclose a copy of my license and a letter of explanation which seem to have done the trick. No problems. 

WA8TOD

Re: si5351a CLK drive levels in uBITX #ubitx

Jerry Gaffke
 

Yup.
In addition to under-driving the mixer, we are over-loading the si5351 outputs.
Some previous speculation regarding the si5351 attenuators can be found here:
    https://groups.io/g/BITX20/message/46122



On Wed, Jul 25, 2018 at 01:05 PM, ajparent1/KB1GMX wrote:
I agree full throttle and cut the attenuators out or down.  If anything I'd expect the birdies 
to go down with the mixers run at a reasonable level rather than underdriven.

I have to assemble everything to measure that but I'd expect better results.

Re: uBITX Increasing 28 Mhz output by changing C81 #ubitx-help

 

Allison :

Thanks for your comments.  I will consider them for a future round of mods (I do have a pile of 2n2222a's). 
I am actually pretty much OK with the power out that I have at the moment, I was just hoping to even it out a bit with a 
couple of simple component changes. 

I think I am getting about 3w out on 20m with 12+v in and the difference between that and 5W is 40m not worth worrying about.
Also 1W out on 10m is not something I am going to have to be very concerned about until propagation significantly improves on that band,
with an upswing in the sunspot cycle. Realistically 1 W and a wet noodle for an antenna is all you need to work the world on
10m anyway, when it is open. 

I think that it is time to start thinking about the logistics of getting my rig into a permanent enclosure.  

Cheers

Michael VE3WMB