Date   
Re: Amazing video from ATT archives freely available on youtube

Tom, wb6b
 

On Thu, Apr 25, 2019 at 01:31 AM, Laurence Oberman wrote:
This is amazing. No computer graphics no simulation
Hi,

Here is a video (film), in 1959, counting individual photons with nothing but old oscilloscopes, incandescent lamps and a motorized spinning pinhole. Also amazing.

https://youtu.be/HUsNFLpDsTw

I love these old videos.

Better yet, no handwaving, screaming and mugging for the camera, in artificially created excitement about the amazement of quantum physics and light.

Tom, wb6b


Additional comment: The mechanical depiction of SWR video was really interesting, too. Just one point. If you don't have a significant part of a wavelength in a cable or other connection, SWR really is not a factor. Unless you are dealing with microwaves, if you are talking about the impedance match between stages in a transmitter, most likely a "mismatch" in driving the finals (for example, as I often hear described) is not reflecting anything nor has an SWR. But it is still a convenient way to describe impedance matching as so many tools, like smith charts, are built around the concept. 

Re: 2N2222A getting super hot

Roy Appleton
 

I just ordered this, looks like it would work well for measuring component temperatures! 
https://m.banggood.com/HT-175-Infrared-Thermal-Imaging-Camera-Digital-Thermal-Imager-20300-p-1249453.html

Roy
WA0YMH

Re: S Meter output sticking when changing tune step. #ubitx-help #smeter #ubitx

KE2GKB
 

Hi Derek the device has a bleeder resistor on it already. It is what is selected via the switch and controls the "Decay" time. Have you calibrated the S-Meter display using the ubit configuration manager from KD8CEC? Its possible some values are set weird!

As mentioned in the email from David, Its possible that when you change tune that the firmware is what is also causing the delay, We have no real way to know. I know on my V3 its quite snappy.

-- Tim Keller - KE2GKB https://shop.kit-projects.com

Re: S Meter output sticking when changing tune step. #ubitx-help #smeter #ubitx

derek (G4VWI)
 

Many thanks for your reply. 
I am trying different settings using KD8CEC manager.
I have made some progress but it is still  a bit sluggish. (I2C update on the cards).
I take it no output should be present with the board grounded and "switched out".
Computer hash does not help when reading values. That is why I asked what values others had measured and used.
Thanks again.
Derek G4VWI

Re: Amazing video from ATT archives freely available on youtube

Nigel
 

Thank you for sharing, absolutely fascinating for sure!  

Wonder how (if?) high schools teach same subject / topic  nowadays?

Guess its the 'old school' I belong to that make watching enjoyable, perhaps not enough 'showbiz' or 'drama' for today's young students.... (as also noted in another comment).

73

Nigel ZS6RN ex G8DEV

Re: S Meter output sticking when changing tune step. #ubitx-help #smeter #ubitx

 

Correct the AGC must be in slow or fast to get a s-meter reading
--
David

 N8DAH
Kit-Projects.com

Shop is open!

Re: Are these output watt rating crazy?

Adrian Chadd
 

.... how'd you get it to tx on 160? :)


-a


On Thu, 25 Apr 2019 at 07:42, Mark Hatch <mark2382@...> wrote:
Just got my V4 uBitx operational. Currently, as designed with no mods.

Got a new Diamond Watt/SWR meter (SX200) and fired it up using CW into a dummy load. Got the following...

160M   20w
80        15
40          7
30          8
20        15
17          8
15          5
13          7
10          5

No difference (as expected on pep vs average)

The higher frequencies seem to be similar to what others have reported, perhaps a little high.  But 160, 80 and 20 just seem far to high and makes me wonder whether the "new" meter has a calibration issue.

73
Mark
AJ6CU

Re: For Sale: 3 Factory Raduinos #ubitx

avavra1@...
 

Hi Jim:

Are any of them pin compatible with a Ver 4 motherboard as far as you know?

TIA de Andy, KD3RF

Re: Are these output watt rating crazy?

Mark Hatch
 

LOL...  Did not know it wasn't supposed to...  It did into a dummy load. Have the latest KD8CEC installed if that matter. 

Mark

Re: Are these output watt rating crazy?

MadRadioModder
 

It will transmit there… just no output filter…

 

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Adrian Chadd
Sent: Thursday, April 25, 2019 11:12 AM
To: BITX20@groups.io
Subject: Re: [BITX20] Are these output watt rating crazy?

 

.... how'd you get it to tx on 160? :)

 

 

-a

 

 

On Thu, 25 Apr 2019 at 07:42, Mark Hatch <mark2382@...> wrote:

Just got my V4 uBitx operational. Currently, as designed with no mods.

Got a new Diamond Watt/SWR meter (SX200) and fired it up using CW into a dummy load. Got the following...

160M   20w
80        15
40          7
30          8
20        15
17          8
15          5
13          7
10          5

No difference (as expected on pep vs average)

The higher frequencies seem to be similar to what others have reported, perhaps a little high.  But 160, 80 and 20 just seem far to high and makes me wonder whether the "new" meter has a calibration issue.

73
Mark
AJ6CU


Virus-free. www.avg.com

--

…_. _._

Re: Are these output watt rating crazy?

 

Hi,

The output will vary depending on the supply voltage, and on the setting of the driver potentiometer.  I doubt whether the latter is set precisely at the factory, so the boards will probably vary initially on their output.  On CW, some bands have more harmonics than others, so this will also show as variation in output wattage (since wattmeters are not frequency selective).  So considering these factors, I don't think your numbers are crazy.

73,


Mark.

Re: For Sale: 3 Factory Raduinos #ubitx

Jim Sheldon
 

They ALL are - they are genuine factory Raduino's that came with my kits. Since I do not use the Raduino at all, these are surplus to my needs.  I did remove the bubble wrap and mark the version of firmware that was in the NANO on the NANO's MPU. You can flash the Version 4.3 or CEC or whatever firmware you are using into the NANO.  The V5 ones do come with and are marked factory V5.1 already in them - they came from the factory.

Jim

Re: Are these output watt rating crazy?

 

Hmm,

On second thought, adding up all the harmonics probably won't make much of a difference.  More likely the variations in the individual bands is due to uneven reponse in the stages and mixer prior wrt frequency, and maybe too if some of the LPF's are too close to the band edge.

73,


Mark.

Re: Are these output watt rating crazy?

Mark Hatch
 

Thanks!

Ignoring 160,  I was just surprised to see 15w on 80 and 20. I know I didn't buy a Bird meter, but the spec on the 20w scale is 7.5%....

Mark

Re: Bitx 20 3b "ugly" build

MadRadioModder
 

I did this last year… constructed an entire uBITx v4 from scratch but built it in modules for each stage so that I could replace stages with newer experimental designs to try them out.  Two or three others did the same thing.  I designed a backplane with power, agc, control signals that the modules could plug into.  In the end I replaced the front end with a PGA103+ mmic and two PE4306 attenuators, other stages with dual gate ultra-low noise FETs (for AGC control).  Also used a modified version of the K2 crystal filter scheme for variable pass-band.  Then built a second receiver and modified the CEC code fit into a Teensy 3.6 to control both receivers at once (split).  The teensy also does DSP filtering (passband, notch, etc. for both receivers).

 

A couple things to glean from this experience (and to conform to good RF design in general) were:  1) bypass the rails and control lines well… everywhere. Then do it again.  2) enclose each stage in a shield (simple made from circuit boards works perfectly)… this keeps cross talk and spikes from adjacent stages to a minimum

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of n7ql.us@...
Sent: Thursday, April 25, 2019 6:59 AM
To: BITX20@groups.io
Subject: [BITX20] Bitx 20 3b "ugly" build

 

I am getting ready to attempt a Bitx 20 3b build but instead of PCBs I am going to go the "ugly" route. I have many of the parts already and the few I don't I'll buy but it will be cheaper than buying the whole kit. I am wondering if anyone here has gone this route and how well it turned out. Thank you.


Virus-free. www.avg.com

--

…_. _._

Re: Bitx 20 3b "ugly" build

Laurence Oberman
 

Would love to see a picture of your Rig  MadRadioModder
Sound like a really good project you built.
Your forum name is definitely is earned for that work :)
Regards
Laurence

On Thu, Apr 25, 2019 at 1:44 PM MadRadioModder <madradiomodder@...> wrote:

I did this last year… constructed an entire uBITx v4 from scratch but built it in modules for each stage so that I could replace stages with newer experimental designs to try them out.  Two or three others did the same thing.  I designed a backplane with power, agc, control signals that the modules could plug into.  In the end I replaced the front end with a PGA103+ mmic and two PE4306 attenuators, other stages with dual gate ultra-low noise FETs (for AGC control).  Also used a modified version of the K2 crystal filter scheme for variable pass-band.  Then built a second receiver and modified the CEC code fit into a Teensy 3.6 to control both receivers at once (split).  The teensy also does DSP filtering (passband, notch, etc. for both receivers).

 

A couple things to glean from this experience (and to conform to good RF design in general) were:  1) bypass the rails and control lines well… everywhere. Then do it again.  2) enclose each stage in a shield (simple made from circuit boards works perfectly)… this keeps cross talk and spikes from adjacent stages to a minimum

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of n7ql.us@...
Sent: Thursday, April 25, 2019 6:59 AM
To: BITX20@groups.io
Subject: [BITX20] Bitx 20 3b "ugly" build

 

I am getting ready to attempt a Bitx 20 3b build but instead of PCBs I am going to go the "ugly" route. I have many of the parts already and the few I don't I'll buy but it will be cheaper than buying the whole kit. I am wondering if anyone here has gone this route and how well it turned out. Thank you.


Virus-free. www.avg.com

--

…_. _._

Re: Are these output watt rating crazy?

Jerry Gaffke
 

If transmitting on 160 meters, the uBitx would have the 80 meter transmit LPF filter selected.
Must have an external 160 meter low pass filter between rig or antenna,
or you will be sending some nasty 2'd and 3'rd harmonics (almost a square wave!).

Firmware should probably display a warning when 160m is selected.

Jerry, KE7ER


On Thu, Apr 25, 2019 at 09:23 AM, Mark Hatch wrote:
LOL...  Did not know it wasn't supposed to...  It did into a dummy load. Have the latest KD8CEC installed if that matter. 

Mark

Re: Amazing video from ATT archives freely available on youtube

Jerry Gaffke
 

SWR was about the only thing they could measure 100 years ago, 
just run some sort of RF voltmeter along the open wire transmission line to the antenna
and measure the peaks and troughs.

Would be more informative to know the complex impedance of the load,
but SWR is still easier to measure and it's what hams are most familiar with.

Jerry, KE7ER


On Thu, Apr 25, 2019 at 08:01 AM, Tom, wb6b wrote:
Additional comment: The mechanical depiction of SWR video was really interesting, too. Just one point. If you don't have a significant part of a wavelength in a cable or other connection, SWR really is not a factor. Unless you are dealing with microwaves, if you are talking about the impedance match between stages in a transmitter, most likely a "mismatch" in driving the finals (for example, as I often hear described) is not reflecting anything nor has an SWR. But it is still a convenient way to describe impedance matching as so many tools, like smith charts, are built around the concept. 

Re: Amazing video from ATT archives freely available on youtube

Laurence Oberman
 

Yep, For me the thing about this video was the ingenuity to use the
pivoting metal rods like that to show the wave motion.
Amazing, still cant get over how he came to that idea.

On Thu, Apr 25, 2019 at 4:45 PM Jerry Gaffke via Groups.Io
<jgaffke=yahoo.com@groups.io> wrote:

SWR was about the only thing they could measure 100 years ago,
just run some sort of RF voltmeter along the open wire transmission line to the antenna
and measure the peaks and troughs.

Would be more informative to know the complex impedance of the load,
but SWR is still easier to measure and it's what hams are most familiar with.

Jerry, KE7ER

On Thu, Apr 25, 2019 at 08:01 AM, Tom, wb6b wrote:

Additional comment: The mechanical depiction of SWR video was really interesting, too. Just one point. If you don't have a significant part of a wavelength in a cable or other connection, SWR really is not a factor. Unless you are dealing with microwaves, if you are talking about the impedance match between stages in a transmitter, most likely a "mismatch" in driving the finals (for example, as I often hear described) is not reflecting anything nor has an SWR. But it is still a convenient way to describe impedance matching as so many tools, like smith charts, are built around the concept.

Re: #parts #parts

Doug W
 

You did not say which radio you are interested in.  For the µBITX http://www.hfsignals.com/index.php/ubitx-circuit-description/ is a good place to start.  Toward the bottom of the page under the heading Coil Details you will find information on the inductors.  The component values are shown on the drawings on that page as well.  For the BITX40 you want http://www.hfsignals.com/index.php/2017/11/23/bitx40-circuit-description/
--
www.bitxmap.com