Date   

Buyer beware! RD16HHF1

victorladeira@...
 

   Got 2 RD16HHF1 off E bay . https://www.ebay.com/itm/RD16HHF1-TO-220-Mitsubishi-HF-RF-Power-MOSFET/291322273944.  They are clearly labeled as such but the pin out test as GDS instead of GSD. Pretty weird so not sure what going on. He sent me two more mosfets which also had the same pin out. Anybody run into this? Not sure if I want to smoke test my uBitx with these.
                                                                                                                         Victor AL3K


Re: boosting the power on 28 MHz #ubitx

victorladeira@...
 

  So with this mod I can just drop in the RD16HHF1 (crossing the drain and source)? And set bias for 250ma each? 


Re: ubitx mic pre-amp not working, no SSB

Skip Davis
 

Tim I not sure if anyone has answered your request yet but I made some measurements on my uBITX.
My Voltages at the same points you showed:
TX 12.2vdc
R66,R65 junction 11.86vdc
R65, C63, Q6 collector junction 10.4vdc
Q6 emitter, R63 junction 1.42vdc
Q6 base, R61, R62 junction 2.09vdc

These were taken without audio, ptt only, I hope this helps.

Skip Davis, NC9O

On May 11, 2018, at 17:42, Tim Gorman <tgorman2@cox.net> wrote:

Onward and upward to another problem! My mic pre-amp is not working.
The voltages seem to be all screwed up.

Attached is a png showing the pre-amp schematic and the DC voltages I
measure.

There is way too much current through the collector resistor dropping
the idle voltage to .52v. Where that current is going is beyond me. The
emitter voltage is only .44v which tracks with a 1.12v base voltage
which should indicate about a 0.5ma current through the transistor at
idle.

I've replaced Q6 and C60 and nothing changed.

I thought maybe C61 was shorted but when I removed it and turned the
unit on, it immediately went into SSB transmit mode -- with no mic or
PTT hooked up! That *really* baffles me!

I measure no DC voltage on the mixer side of C63.

Does anyone have any suggestion on where to look?

tim ab0wr




<mic_preamp.png>


Mike audio

VE7CWS WRSeiler <waltrseiler@...>
 

Hello folks, I need some ideas on what might be the cause of tight audio, that’s the complaint I get from others so I’m guessing that the audio output from the mike is narrow. I’ve checked the wiring and connections, all appears fine. Perhaps a faulty mike element??? Everything is stock on this build and the mike polarity is correct. Just for the heck of it I’ll try another electret element as soon as I can find one.

cheers and 73
WRS VE7CWS


Re: SMT sizes in µBITX

Howard Fidel
 

I spent the last 10 years of my professional career designing intraoral sensors for Schick/Sirona/Dentsply. We routinely worked with 0201 parts. They were too small for me to work on, but our technicians did manage to solder them. I can handle down to 0402 but prefer 0805 parts or larger.

Howard
Quoting Ashhar Farhan <farhanbox@gmail.com>:

I tried to keep all resistors and capacitors to 1206. However, some of the
C0G caps in the filters were not available readily. Hence, we chose the
more common 0805 for those.

- f

On 11 May 2018 8:45 am, "Jack Purdum via Groups.Io" <jjpurdum=
yahoo.com@groups.io> wrote:

Not too long ago I sneezed on a pile of 0402 SMD and, after the cloud hit
the ground, I had a 100W transceiver!

Jack, W8TEE


On Thursday, May 10, 2018, 11:05:03 PM EDT, Terry Morris <
terry.kb8amz@gmail.com> wrote:


I am in awe with anything smaller than 1608/603.


Terry - KB8AMZ
Brimfield Twp, OH USA
Linux User# 412308, Ubuntu User# 34905
OSs: LM18.2 64bit, Ubuntu 16.04, tahrPup64 64bit, Raspian
Orgs: PCL70-FOP, NTHS, ALUG, ARRL, PCARS#78, NAQCC#6668, NO-QRP-C,
QRP-ARCI#8855, SKCC#14195, USN 1965-1969 AG3

I chair the PCARS CW/QRP SIG and Linux for Hams SIG, second and fifth
Tuesday

my computer, my opinion

On Thu, May 10, 2018 at 10:31 PM, Jack Purdum via Groups.Io <
jjpurdum=yahoo.com@groups.io> wrote:

[image: Inline image]



On Thursday, May 10, 2018, 8:30:18 PM EDT, William Cullison <
wa8vih@gmail.com> wrote:


I have never worked with SMT and have no idea what size various components
are. Could someone please enlighten me.

73 Bill WA8VIH/4


Re: uBITX drive level.. #ubitx

Jerry Gaffke
 

Vgs(thresh) spec for the IRF510 is min of 2v, max of 4v,   fifth spec down on page two of the datasheet:
    https://www.vishay.com/docs/91015/sihf510.pdf

This means the gate voltage for a specific drain current can vary as much as 4-2 = 2volts from device to device.
That's why there are two pots to set gate bias individually, not just one.

If you can set the drain current to 100ma on each of the two IRF510's, they are likely just fine.

Be very careful about setting those pots to "a lot more" than 100ma, 
that's a good way to make the IRF510's pop from the heat.
For example, if you bring the bias current up to 1 Amp, then both IRF510's are dissipating 12v*1Amp = 12 Watts,
and the IRF510 die could be much hotter than the IRF510 tab. 
So, if they are both at 100ma, I'd leave well enough alone.

You don't say what band you are getting 5W out on.
But that's in the ballpark of what others are getting. 

Jerry


On Fri, May 11, 2018 at 08:06 pm, Ralph Mowery wrote:
I'm getting the same 5W output on CW and SSB (with a loud "helloooo").  I also noticed that my PA bias pots when set to the proper 100ma per IRF510 are at slightly different settings.  RV1 is turned all the way up.

Does this sound like a drive level issue?  Or do I maybe need to replace the IRF510's?


Re: uBITX drive level.. #ubitx

Ralph Mowery
 


Try cutting the bias pots to minimum bias.  Then turn one of them up to the desired bias.  Then turn it back to minimum.  Then try turning the other pot to the desired bias.  If each pot will adjust the bias to the desired amount and even a lot more, then the IFR510 connected to that pot should be ok.  If you can not raise the bias to both of the equally I would look at changing the IFR510.


On Fri, May 11, 2018 at 2:36 PM, KE0GYC <dragonfanatic90@...> wrote:
I'm getting the same 5W output on CW and SSB (with a loud "helloooo").  I also noticed that my PA bias pots when set to the proper 100ma per IRF510 are at slightly different settings.  RV1 is turned all the way up.

Does this sound like a drive level issue?  Or do I maybe need to replace the IRF510's?



Re: ubitx_20.ino does not compile, anybody else encounter this? #ubitx-help #ubitx #arduino #firmware

freefuel@...
 

This is the error I get when trying to compile the original code. 

Arduino: 1.8.6 Hourly Build 2018/05/03 04:12 (Mac OS X), Board: "Arduino Nano, ATmega328P"
 
Build options changed, rebuilding all
/Users/user/Downloads/ubitx-master/ubitx_20/ubitx_menu.ino: In function 'int menuBand(int)':
ubitx_menu:26:5: error: expected primary-expression before 'return'
 *   return;
     ^
/Users/user/Downloads/ubitx-master/ubitx_20/ubitx_menu.ino: In function 'int menuCWSpeed(int)':
ubitx_menu:211:7: error: expected primary-expression before 'return'
 *     return;
       ^
exit status 1
expected primary-expression before 'return'
 
This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.


-Justin N2TOH 


Re: Antenna Impedance Confirmation

William Cullison <wa8vih@...>
 

Kees,

Well you certainly got this discussion going hot and heavy. Thanks

73 Bill WA8VIH

On Fri, May 11, 2018 at 6:42 PM, Vince Vielhaber <vev@...> wrote:
Noise level was at least 10 over on the B40, based on how much signal I had to push thru from the service monitor.  It was both radiated and conducted.

Vince.

On 05/11/2018 05:46 PM, Kees T wrote:
Vince,

I figure they would be noisy but just how noisy and can they be shielded
sufficiently ? Series RF beads/chokes, etc ?

Or take a real low tech approach and drive "3?" red LEDs depending on
voltage level. All you are looking for is the "dip" and the battery
voltage idea goes out the window.

73 Kees K5BCQ


--
  Michigan VHF Corp.   http://www.nobucks.net/   http://www.CDupe.com/
                          http://www.metalworkingfun.com





Re: Enclosure

JOHN CRONHELM <johncronhelm@...>
 

Did he acknowledge receipt of order after you ordered and sent the money.  There were 71 available when I ordered.  Do you just have to sit tight until notified by PayPal?  I sent an email,but no reply.  Just needed to know what to expect.
Many thanks,
John vo1jcc.


Re: SWR

Jerry Gaffke
 

I said
>    So best case resolution of the detectors using the 10 bit ADC on the Nano is 25000/1024 or about 25mW

Wrong
It's better than that.
Power is proportional to voltage squared, and we're reading peak RF voltage.

With a maximum measurable voltage of 50 volts peak, that's  50 * 0.707 = 35.35 volts rms of transmitted RF.
Maximum measurable power is thus 35.35vrms * 35.35vrms / 50ohms = 25 Watts.

An LSB step of our 10 bit ADC is 35.35vrms/(2**10) = 35.35 / 1024 = 0.0345 volts rms.
And so at the bottom of the range of our 10 bit ADC, we see discrete power levels of 0.0345*0.0345/50 = 24 microwatts.
So if everything works great and the bias is adjusted carefully and the diode is still linear down there, this could
conceivably be usable down to milliwatt levels.  I'll be happy if it's usable down to 100mW.

And that's with the ADC using the standard 5v reference.
Going to the ATMega328P's internal 1.1v reference gives us a voltage step nearly 5 times smaller,
and power in watts is 5*5 = 25 times smaller.  So instead of discrete power levels of 24 microwatts
at the bottom end, it would be more like 5 microwatts

We'll have trouble with noise long before we have trouble with the inherent resolution.

Jerry


On Fri, May 11, 2018 at 03:10 pm, Jerry Gaffke wrote:
I'm shooting for a max reading of 25 Watts into 50 ohms. 
So best case resolution of the detectors using the 10 bit ADC on the Nano is 25000/1024 or about 25mW
Could have a low range by going to the 1.1v reference voltage on the Nano ATMega38P's ADC, bringing that to around 5mW.
    https://www.arduino.cc/reference/en/language/functions/analog-io/analogreference/


Re: SWR

Doug W
 

On Fri, May 11, 2018 at 03:10 pm, Jerry Gaffke wrote:
Or whistle into the mike, assuming you can whistle a pure single frequency note.
I can't, but my phone can https://play.google.com/store/apps/details?id=com.keuwl.functiongenerator
 
--
www.bitxmap.com


Re: Broadband HF Folded Dipole Antennas

William R Maxwell
 

I have a Chinese copy of the old B&W folded dipole and have only used it on 2 ocassions, Kees. I saw considerable losses when compared to a G5RV that we used as a comparison at the same campsite, although I did not try it across all the HF bands to see if the loss varied, as Gordon reports.


Added to that, mine was obviously aimed at the military or commercial market and is therefore damned heavy! Not for QRP use methinks, at least not for portable use.


Bill, VK7MX


On 12/05/2018 1:07 AM, Gordon Gibby wrote:

Kees --- I particularly DISLIKE those broadband tilted-folded-terminated antennas because they ahve HUGE LOSSES on various  ferquencies, as much as 10 dB.


I much prefer something like a well-designed off center fed dipole with current/voltage baluns and the resullting abilaity to work reasonably well across wide swaths of the spectrum --- or an auto tuner and a balanced line fed random dipole.


10 dB losses jjust make me shudder inside.    


Gordon Gibby



From: BITX20@groups.io <BITX20@groups.io> on behalf of Kees T <windy10605@...>
Sent: Friday, May 11, 2018 10:47 AM
To: BITX20@groups.io
Subject: [BITX20] Broadband HF Folded Dipole Antennas
 
Broadband HF Folded Dipole Antennas at QRP power levels.......any experience with them out there ? The advantage of these is "no tuner required". I recall B&W selling these in the 60's and the military likes them because they don't require tuning and are good from 2-30MHz with a maximum SWR of about 2:1 and since they are wire antennas, you can roll them up and carry them easily.

73 Kees K5BCQ


Re: RadI2Cino - I2C replacement kit for the uBITX Raduino Now with Teensy 3.6 adapter #ubitx

Jerry Gaffke
 

Arthur,

Your kit is probably the uBitx, sometimes called the mBitx:
    http://www.hfsignals.com/index.php/ubitx/
  
But it could be the Bitx40:
    http://www.hfsignals.com/index.php/bitx40/

That's about all it could be if you bought it from hfsignals.com.
If you bought it elsewhere, there's another dozen possible variants of  the Bitx out there.
So saying you have a Bitx is not quite good enough.

We've been assuming you have a uBitx radio.
The stock firmware that is programmed into the uBitx by hfsignals when it ships is the ubitx_20 firmware up on github:
   https://github.com/afarhan/ubitx

If you have a Bitx40 radio, then you will need to use other firmware, I'd recommend this:
   https://github.com/amunters/bitx40


Once you get firmware installed again and the radio working,
then there is other firmware to try out that will give more bells and whistles.

Hopefully not too many whistles.  ;-)

Jerry, KE7ER


On Fri, May 11, 2018 at 03:12 pm, artns7e wrote:
That eluded me due to I don't have the ubit_20 kit  I have the BITX Transceiver from HF signals with Raduino circuit with uBITX's software.


Re: Antenna Impedance Confirmation

Vince Vielhaber
 

Noise level was at least 10 over on the B40, based on how much signal I had to push thru from the service monitor. It was both radiated and conducted.

Vince.

On 05/11/2018 05:46 PM, Kees T wrote:
Vince,

I figure they would be noisy but just how noisy and can they be shielded
sufficiently ? Series RF beads/chokes, etc ?

Or take a real low tech approach and drive "3?" red LEDs depending on
voltage level. All you are looking for is the "dip" and the battery
voltage idea goes out the window.

73 Kees K5BCQ


Re: FT8 on uBITX experiences

kg9rb@...
 

Hoping all u digital gurus can help. 
I'm wanting to use ft8 on my unit. 

I never have used digital except some packet early in life. I know there is an USB port on the radruino board. I know I can use a mini USB to regular USB to computer. Now the questions I have are, 

1.what software do I need to load the radruino to recognize this. 
2.what software is everyone using that is compatible to the units after any upgrades. 
3.basically help. I started out with a johnson Viking transmitter crystal controlled with a hallicrafters s38b receiver with light switch controlling a Relay for to, r control. 😊used hw8,paccomm transceivers, ten ten 509,ss transceiver ,some mfj,. So mainly analog Operations with cw, qrp straight key. If anyone has a tutorial for hams like me would u send a link. I use vertical antennas with outbacker jr and homemade aluminum pipe antenna with loading coil. Also end fed dipole capable of multiband with my mfj versatuner. Anyone up to guiding me to a tutorial on this ft8 ,etc.? I'm computer savvy but software lacking. 

73s
David
Ka9koj
My email reflects my recent callsign. I gave it up for my original callsign I obtained when I was first licensed in 1980
kg9rb@...


Re: ubitx_20.ino does not compile, anybody else encounter this? #ubitx-help #ubitx #arduino #firmware

freefuel@...
 

ah Thank you Marco, I will make sure I have that library installed. that may be the reason I keep getting compile errors for the original code. 

-Justin N2TOH 


Re: SWR

Jerry Gaffke
 

Here's a description of the hardware involved:
    https://groups.io/g/BITX20/message/47634


On Fri, May 11, 2018 at 03:10 pm, Jerry Gaffke wrote:
Problem with the two Nano readings goes away if you tune up the antenna in CW mode.
Or whistle into the mike, assuming you can whistle a pure single frequency note.


Re: RadI2Cino - I2C replacement kit for the uBITX Raduino Now with Teensy 3.6 adapter #ubitx

artns7e <Artns7e@...>
 

thanks, Jerry and Jack;  yes I am new to the Arduino world 
That eluded me due to I don't have the ubit_20 kit  I have the BITX Transceiver from HF signals with Raduino circuit with uBITX's software.

I see now there are a few ways to load the Arduino nano device  with (.HEX) a.( .INO ) File in a subdirectory with  6 other  files  from ubitx_20/ubix_20.ino

I will try this next again thank All of you for the Help.
Arthur Ripple  NS7E 


Re: SWR

Jerry Gaffke
 

Problem with the two Nano readings goes away if you tune up the antenna in CW mode.
Or whistle into the mike, assuming you can whistle a pure single frequency note.

It might sort of work well enough on regular SSB phone transmisssions with large enough caps on the detector outputs.
I'd have my doubts about the SWR figure in that case, but the forward and reverse power readings might be useful.

Here's a couple old posts:
    https://groups.io/g/BITX20/message/48408
    https://groups.io/g/BITX20/message/48422

So the bias offset could be read once immediately before we start transmitting 
at the outputs of the two diode detectors, the same points we read during transmit.
Alternately, we could read the offset once during calibration and store it to eeprom.
Or read it once during development and hard code that offset into the firmware.
I think that last one would work well enough, better than most such detectors which have no offset adjustment.

Then whenever we read the diode detectors for power and swr, we subtract that offset.

I'm shooting for a max reading of 25 Watts into 50 ohms. 
So best case resolution of the detectors using the 10 bit ADC on the Nano is 25000/1024 or about 25mW
Could have a low range by going to the 1.1v reference voltage on the Nano ATMega38P's ADC, bringing that to around 5mW.
    https://www.arduino.cc/reference/en/language/functions/analog-io/analogreference/

So when measuring 100mW, the 5mW resolution means we might see 95mW, 100mW, or 105mW.
If everything works perfectly and the ADC's are really 10 bit, this could be useful down to around 100mW.

Jerry, KE7ER



On Fri, May 11, 2018 at 02:36 pm, Kees T wrote:
OK, sounds good to me and eliminates the external ADC and S/H circuitry. I thought there was a problem syncing up the two Nano readings here also ? I really like those HSMS-2815 matched diodes. Where are you going to read the bias offset to subtract from the ADC reading ? ....may change over time.