Date   
Re: receiver overload

Jerry Gaffke
 

Indeed.


On Sat, Apr 21, 2018 at 09:24 am, Tim Gorman wrote:
The "noise" from the lightning strike comes through no matter where the tuner is set.

Re: RTL SDR

Jerry Gaffke
 

Thanks for the info!
Sounds like the  "Experimental: HF Direct Sampling Mode" to receive frequencies 
from 500khz to 28.8mhz  is not quite ready for prime time.
Or at least, not for punters like me.
Good to know.

Jerry, KE7ER


On Sat, Apr 21, 2018 at 09:20 am, Doug W wrote:
I have the same dongle and am happy with it.  You can order it on Amazon https://www.amazon.com/RTL-SDR-Blog-RTL2832U-Software-Defined/dp/B0129EBDS2 for the same price with prime shipping to boot.  I did experiment with direct sampling but in the end broke down and bought an upconverter https://www.amazon.com/gp/product/B009LQT3G6 and later the enclosure.  It is not lost on me that all of that costs about the same as a BITX40 and by the time you throw in random connectors and what not about the same as a µBITX.  I have not tried connecting it to a Pi but using an otg adapter I have used it with an old android phone.  I haven't used it on the phone in a while but I seem to remember using the free version of SDR Touch.  Prior to having a real antenna I was using this balun https://www.amazon.com/gp/product/B00R09WHT6 and random wire with limited success and a few cheap telescoping whip antennas.
I just did a quick search and as usual Adafruit has a solid tutorial on with links to libraries https://learn.adafruit.com/freq-show-raspberry-pi-rtl-sdr-scanner?view=all
For general ideas and knowledge you can't beat https://www.rtl-sdr.com/

Re: receiver overload

K9HZ <bill@...>
 

Here: https://www.arraysolutions.com/antennas/static-bleed-inductor



Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ

Owner - Operator
Big Signal Ranch – K9ZC
Staunton, Illinois

Owner – Operator
Villa Grand Piton – J68HZ
Soufriere, St. Lucia W.I.
Rent it: www.VillaGrandPiton.com
Like us on Facebook!

Moderator – North American QRO Group at Groups.IO.

email: @Doc_Bill

-----Original Message-----
From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Tim Gorman
Sent: Saturday, April 21, 2018 11:25 AM
To: BITX20@groups.io
Subject: Re: [BITX20] receiver overload

Noise from static buildup varies with the weather and wind. If you think you have static buildup then all you have to do is disconnect your antenna, use a jumper cable to short each element to ground, and then reconnect the antenna. If your noise level drops significantly then you had static buildup. If not, then you are hearing atmospheric noise and/or phase noise in the receiver. The two can be differentiated by just disconnecting the antenna to see what kind of noise drop you see.

Noise from static buildup is typically not static. It does not sound like the white noise, more like a buzzing or popping, and sometimes even like a musical tone.

A tuner, even one that is isolated by a capacitor from the antenna, typically won't "tune" static buildup noise. The noise is basically from small discharges caused by charge equalization. Can you use your tuner to to "tune-in" or "tune-out" the noise from the static discharge of a lightning strike? Mine won't. The "noise" from the lightning strike comes through no matter where the tuner is set.

If noise in the receiver goes up and down as you operate your tuner to find the best match between your receiver and your antenna it's because it is actually working. It is highly unlikely that the noise you hear going up and down is from static buildup on the antenna.

tim ab0wr

On Fri, 20 Apr 2018 20:21:25 -0500
"K9HZ" <@Doc_Bill> wrote:

I guess that then assumes you have a very simple tuner (Cap-L leg)?
No impedance transformers, inductors to ground, etc.


Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ
PJ2/K9HZ

Owner - Operator
Big Signal Ranch – K9ZC
Staunton, Illinois

Owner – Operator
Villa Grand Piton – J68HZ
Soufriere, St. Lucia W.I.
Rent it: www.VillaGrandPiton.com
Like us on Facebook!

Moderator – North American QRO Group at Groups.IO.

email: @Doc_Bill



-----Original Message-----
From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Tim
Gorman Sent: Friday, April 20, 2018 8:18 PM
To: BITX20@groups.io
Subject: Re: [BITX20] receiver overload

I agree! But if the problem here is static buildup then a tuner won't
help any more than the coax connector on the rig!

tim ab0wr

On Fri, 20 Apr 2018 17:37:45 -0500
"K9HZ" <@Doc_Bill> wrote:

That is not where you want static charges dissipating! Chokes to
ground, resistors, at the antenna. All a better place for it (the
fire) to happen.


Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ
PJ2/K9HZ

Owner - Operator
Big Signal Ranch – K9ZC
Staunton, Illinois

Owner – Operator
Villa Grand Piton – J68HZ
Soufriere, St. Lucia W.I.
Rent it: www.VillaGrandPiton.com
Like us on Facebook!

Moderator – North American QRO Group at Groups.IO.

email: @Doc_Bill



-----Original Message-----
From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Tim
Gorman Sent: Friday, April 20, 2018 4:05 PM
To: BITX20@groups.io
Subject: Re: [BITX20] receiver overload

I'm sure it happens. But not consistently. You need wind and
something to create the charge like blowing dust. If the tuner is
dissipating the charge why doesn't the rig itself do it, at least
with an unbalanced feed?

tim ab0wr

On Fri, 20 Apr 2018 08:47:00 -0500
"K9HZ" <@Doc_Bill> wrote:

Unless the antenna is picking up a static charge and the antenna
tuner is acting like an impedance to ground draining that charge
off. Don't laugh, it happens.


Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ
PJ2/K9HZ

Owner - Operator
Big Signal Ranch – K9ZC
Staunton, Illinois

Owner – Operator
Villa Grand Piton – J68HZ
Soufriere, St. Lucia W.I.
Rent it: www.VillaGrandPiton.com
Like us on Facebook!

Moderator – North American QRO Group at Groups.IO.

email: @Doc_Bill



-----Original Message-----
From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Tim
Gorman Sent: Friday, April 20, 2018 8:42 AM
To: BITX20@groups.io
Subject: Re: [BITX20] receiver overload

Usually a tuner will increase noise, at least atmospheric noise,
as the tuner creates a match between the receiver and the antenna.
A matched antenna shouldn't "tame" the noise. If that is actually
happening then a closer look at the system might be appropriate.

tim ab0wr



On Fri, 20 Apr 2018 11:39:39 +1000 "John Sharpe"
<johsharpe@...> wrote:

Hi all,

I just had a thought about new users of the uBitx and the
Bitx40.

I have both of these fine rigs but with my good antenna - a
ZS6BKW
<http://www.nc4fb.org/wordpress/zs6bkw-multi-band-antenna/> at
30 feet
- the receivers are swamped by noise and big signals on 40
metres.

When I tested just now a 59+ 10 signal on my IC-7300 was
unreadable on the Bitexes with the big antenna (which has a low
SWR at 40 metres) because of noise. With an antenna of just 6
feet of wire in the shack the signal was readable (but weak) on
the Bitexes!

I usually use a tuner beween the antenna and the Bitexes - that
works fine to tame the noise. Also I have fitted an RF control
to the Bitx40 that helps quieten big signals.

But if you have lots of noise in the receiver and no tuner - try
a smaller antenna on receive (it will be no good for
transmitting). If that improves things maybe you need a tuner or
an RF control.

73s John V2VOL



---
This email has been checked for viruses by AVG.
http://www.avg.com













Re: uBITX #933/2 Finally quite satisfied with operaton #ubitx

Gary Anderson
 

Jim,
Fantastic build!  Quite a milestone in itself to have converted baseline Raduino functionality from an ATmega328 to a Kinetis K66 Arm M4.
It's an extreme upgrade to the 'digital' micro-controller hardware side of the uBITX, paving the way for many additional enhancements and features to be handled by the micro-controller.
I applaud the work you and W2CTX have done here.  

Thank You for sharing your progress,
Gary
AG5TX

Re: RTL SDR

Joe Puma
 

 I think the V3 dongle is a little more robust then the "Experimental: HF Direct Sampling Mode” software option for the RTL2832. When using the just the Q branch of the chip you bypass the R820T2 tuner and can tune in HF directly. The V3 dongle went a extra step from the typical chineese versions of these rtf-sdr dongle to include some filtering and other components as there is no front end after the Q branch.  

You just need a good antenna system but its sensitivity is close to my commercial radio. I think it leaves open a lot of room to build on or integrate into a project very cheaply. It is a perfect sdr receiver for pan adapter alone even if your IF is below 28.8mhz by using the Q branch. 

Joe
KD2NFC

On Apr 21, 2018, at 1:11 PM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:

Thanks for the info!
Sounds like the  "Experimental: HF Direct Sampling Mode" to receive frequencies 
from 500khz to 28.8mhz  is not quite ready for prime time.
Or at least, not for punters like me.
Good to know.

Jerry, KE7ER

On Sat, Apr 21, 2018 at 09:20 am, Doug W wrote:
I have the same dongle and am happy with it.  You can order it on Amazon https://www.amazon.com/RTL-SDR-Blog-RTL2832U-Software-Defined/dp/B0129EBDS2 for the same price with prime shipping to boot.  I did experiment with direct sampling but in the end broke down and bought an upconverter https://www.amazon.com/gp/product/B009LQT3G6 and later the enclosure.  It is not lost on me that all of that costs about the same as a BITX40 and by the time you throw in random connectors and what not about the same as a µBITX.  I have not tried connecting it to a Pi but using an otg adapter I have used it with an old android phone.  I haven't used it on the phone in a while but I seem to remember using the free version of SDR Touch.  Prior to having a real antenna I was using this balun https://www.amazon.com/gp/product/B00R09WHT6 and random wire with limited success and a few cheap telescoping whip antennas.
I just did a quick search and as usual Adafruit has a solid tutorial on with links to libraries https://learn.adafruit.com/freq-show-raspberry-pi-rtl-sdr-scanner?view=all
For general ideas and knowledge you can't beat https://www.rtl-sdr.com/

Re: Hyderabox!

Ken Hansen
 

I strongly detect sarcasm in your post Skip, but others like to complain about such things as 'travesties' and crimes against the ghosts of Benton Harbor, but as a 6m AM transceiver this device is nearly worthless if operating 'good as new', and if it was a 'basket case' in need of serious repair, all the more justification to put the chassis to good use IMHO.

If you go to Dayton/Xenia you'll see plenty of these 2m and 6m lunchboxes offered up for very modest prices, if I find one clean enough I'd get one and do it myself - it's a great case and includes lots of room for a battery pack!

Ken, N2VIP

On Apr 21, 2018, at 11:17 AM, Skip Davis via Groups.Io <skipnc9o=yahoo.com@groups.io> wrote:

Oh no another Benton Harbor lunchbox bit the dust only to be resurrected into a new and glorious life. Or is that a reincarnation as uBITX?

Skip Davis, NC9O

Re: Coast to coast on my ubitx yesterday

_Dave_ K0MBT
 

Hi Tim
Yeah I do have a an oscope but the readings I gave you were from my swr meter. Is my meter right?? It is a cheap cb meter. Still the readings seem to close to what others have posted. Probably is my location and atmospherics but was able to reach out and touch someone as the old Bell ads once said. Yesterday I contacted someone in Tucson and today it was Nantucket. 

My antenna is a homemade choked dipole resonant on 40 and 80. Hung between trees overlooking a ravine. I use recycled RG6 from an old residential television system. I have thought about upgrading it but then I wonder what would be gained. 

I am running 13.8 on all circuits. I put details in my first post. 

I did not check the bias on the pa. But did go through the other calibration steps. The bfo was not set very close. 

This is my main HF rig now and probably will be for some time. I have thought about making the bitx40 a mobile unit. 

Re: show your mic

MAX <max@...>
 

Speaking of mics, I have to raise my voice almost to the level of shouting to get 5 watts out on 40 meters.  Is this normal or should I look for a problem?

 

Regards.

 

Max K 4 O D S.

 

I've Never Lost the Wonder.

 

Antique Electronics Site: http://www.angelfire.com/electronic/funwithtubes/

 

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Mvs Sarma
Sent: Saturday, April 21, 2018 7:17 AM
To: BITX20@groups.io
Subject: Re: [BITX20] show your mic

 

I had grabed a taperecorder mic with 3.5mm mono pin.
 replaced the cable with 2+shield.had a small pushed switchmounted and wired.
 repalced the 3.5mm momo pin to stereo pin. Here is a image of my mic.The pp9 battery helps to imagine the mic size.
regards
 sarma
 vu3zmv

Re: receiver overload

Tim Gorman
 

So what?

That site has nothing to do with how noise from static buildup sounds!

The original message said "I usually use a tuner beween the antenna and
the Bitexes - that works fine to tame the noise."

Again, the tuner can't tame the noise which is actually likely
atmospheric noise or electromagnetic interference from motors, lights,
etc. Those are all induced from external sources which the tuner can't
control.

BTW, the original message said he was using a form of dipole, not a
vertical.

Most antenna tuners, be they an L-network or a T-network, do not provide
a DC path to ground from both elements of an antenna. At least none
that I am familiar with. The only one that does is the Z-match. Most
Z-match tuners today are built for QRP only. Since my equipment has to
do multiple service, having a QRP only tuner isn't high on my to-do
list.

tim ab0wr




On Sat, 21 Apr 2018 12:14:49 -0500
"K9HZ" <@Doc_Bill> wrote:

Here: https://www.arraysolutions.com/antennas/static-bleed-inductor



Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ
PJ2/K9HZ

Owner - Operator
Big Signal Ranch – K9ZC
Staunton, Illinois

Owner – Operator
Villa Grand Piton – J68HZ
Soufriere, St. Lucia W.I.
Rent it: www.VillaGrandPiton.com
Like us on Facebook!

Moderator – North American QRO Group at Groups.IO.

email: @Doc_Bill



-----Original Message-----
From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Tim
Gorman Sent: Saturday, April 21, 2018 11:25 AM
To: BITX20@groups.io
Subject: Re: [BITX20] receiver overload

Noise from static buildup varies with the weather and wind. If you
think you have static buildup then all you have to do is disconnect
your antenna, use a jumper cable to short each element to ground, and
then reconnect the antenna. If your noise level drops significantly
then you had static buildup. If not, then you are hearing atmospheric
noise and/or phase noise in the receiver. The two can be
differentiated by just disconnecting the antenna to see what kind of
noise drop you see.

Noise from static buildup is typically not static. It does not sound
like the white noise, more like a buzzing or popping, and sometimes
even like a musical tone.

A tuner, even one that is isolated by a capacitor from the antenna,
typically won't "tune" static buildup noise. The noise is basically
from small discharges caused by charge equalization. Can you use your
tuner to to "tune-in" or "tune-out" the noise from the static
discharge of a lightning strike? Mine won't. The "noise" from the
lightning strike comes through no matter where the tuner is set.

If noise in the receiver goes up and down as you operate your tuner
to find the best match between your receiver and your antenna it's
because it is actually working. It is highly unlikely that the noise
you hear going up and down is from static buildup on the antenna.

tim ab0wr

On Fri, 20 Apr 2018 20:21:25 -0500
"K9HZ" <@Doc_Bill> wrote:

I guess that then assumes you have a very simple tuner (Cap-L leg)?
No impedance transformers, inductors to ground, etc.


Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ
PJ2/K9HZ

Owner - Operator
Big Signal Ranch – K9ZC
Staunton, Illinois

Owner – Operator
Villa Grand Piton – J68HZ
Soufriere, St. Lucia W.I.
Rent it: www.VillaGrandPiton.com
Like us on Facebook!

Moderator – North American QRO Group at Groups.IO.

email: @Doc_Bill



-----Original Message-----
From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Tim
Gorman Sent: Friday, April 20, 2018 8:18 PM
To: BITX20@groups.io
Subject: Re: [BITX20] receiver overload

I agree! But if the problem here is static buildup then a tuner
won't help any more than the coax connector on the rig!

tim ab0wr

On Fri, 20 Apr 2018 17:37:45 -0500
"K9HZ" <@Doc_Bill> wrote:

That is not where you want static charges dissipating! Chokes to
ground, resistors, at the antenna. All a better place for it (the
fire) to happen.


Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ
PJ2/K9HZ

Owner - Operator
Big Signal Ranch – K9ZC
Staunton, Illinois

Owner – Operator
Villa Grand Piton – J68HZ
Soufriere, St. Lucia W.I.
Rent it: www.VillaGrandPiton.com
Like us on Facebook!

Moderator – North American QRO Group at Groups.IO.

email: @Doc_Bill



-----Original Message-----
From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Tim
Gorman Sent: Friday, April 20, 2018 4:05 PM
To: BITX20@groups.io
Subject: Re: [BITX20] receiver overload

I'm sure it happens. But not consistently. You need wind and
something to create the charge like blowing dust. If the tuner is
dissipating the charge why doesn't the rig itself do it, at least
with an unbalanced feed?

tim ab0wr

On Fri, 20 Apr 2018 08:47:00 -0500
"K9HZ" <@Doc_Bill> wrote:

Unless the antenna is picking up a static charge and the
antenna tuner is acting like an impedance to ground draining
that charge off. Don't laugh, it happens.


Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ
VP5/K9HZ PJ2/K9HZ

Owner - Operator
Big Signal Ranch – K9ZC
Staunton, Illinois

Owner – Operator
Villa Grand Piton – J68HZ
Soufriere, St. Lucia W.I.
Rent it: www.VillaGrandPiton.com
Like us on Facebook!

Moderator – North American QRO Group at Groups.IO.

email: @Doc_Bill



-----Original Message-----
From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of
Tim Gorman Sent: Friday, April 20, 2018 8:42 AM
To: BITX20@groups.io
Subject: Re: [BITX20] receiver overload

Usually a tuner will increase noise, at least atmospheric
noise, as the tuner creates a match between the receiver and
the antenna. A matched antenna shouldn't "tame" the noise. If
that is actually happening then a closer look at the system
might be appropriate.

tim ab0wr



On Fri, 20 Apr 2018 11:39:39 +1000 "John Sharpe"
<johsharpe@...> wrote:

Hi all,

I just had a thought about new users of the uBitx and the
Bitx40.

I have both of these fine rigs but with my good antenna - a
ZS6BKW
<http://www.nc4fb.org/wordpress/zs6bkw-multi-band-antenna/> at
30 feet
- the receivers are swamped by noise and big signals on 40
metres.

When I tested just now a 59+ 10 signal on my IC-7300 was
unreadable on the Bitexes with the big antenna (which has a
low SWR at 40 metres) because of noise. With an antenna of
just 6 feet of wire in the shack the signal was readable (but
weak) on the Bitexes!

I usually use a tuner beween the antenna and the Bitexes -
that works fine to tame the noise. Also I have fitted an RF
control to the Bitx40 that helps quieten big signals.

But if you have lots of noise in the receiver and no tuner -
try a smaller antenna on receive (it will be no good for
transmitting). If that improves things maybe you need a tuner
or an RF control.

73s John V2VOL



---
This email has been checked for viruses by AVG.
http://www.avg.com


















Re: receiver overload

Joe Puma
 

I heard that when you use an antenna tuner you actually raise the noise floor. 🤷🏻‍♂️I understand why but never heard it getting rid of noise. Maybe the tuner provided a better ground then what you had so yea maybe it made it seem like it reduced noise if your antenna system is inadequate.

Joe

On Apr 21, 2018, at 2:03 PM, Tim Gorman <tgorman2@...> wrote:

So what?

That site has nothing to do with how noise from static buildup sounds!

The original message said "I usually use a tuner beween the antenna and
the Bitexes - that works fine to tame the noise."

Again, the tuner can't tame the noise which is actually likely
atmospheric noise or electromagnetic interference from motors, lights,
etc. Those are all induced from external sources which the tuner can't
control.

BTW, the original message said he was using a form of dipole, not a
vertical.

Most antenna tuners, be they an L-network or a T-network, do not provide
a DC path to ground from both elements of an antenna. At least none
that I am familiar with. The only one that does is the Z-match. Most
Z-match tuners today are built for QRP only. Since my equipment has to
do multiple service, having a QRP only tuner isn't high on my to-do
list.

tim ab0wr




On Sat, 21 Apr 2018 12:14:49 -0500
"K9HZ" <@Doc_Bill> wrote:

Here: https://www.arraysolutions.com/antennas/static-bleed-inductor



Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ
PJ2/K9HZ

Owner - Operator
Big Signal Ranch – K9ZC
Staunton, Illinois

Owner – Operator
Villa Grand Piton – J68HZ
Soufriere, St. Lucia W.I.
Rent it: www.VillaGrandPiton.com
Like us on Facebook!

Moderator – North American QRO Group at Groups.IO.

email: @Doc_Bill



-----Original Message-----
From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Tim
Gorman Sent: Saturday, April 21, 2018 11:25 AM
To: BITX20@groups.io
Subject: Re: [BITX20] receiver overload

Noise from static buildup varies with the weather and wind. If you
think you have static buildup then all you have to do is disconnect
your antenna, use a jumper cable to short each element to ground, and
then reconnect the antenna. If your noise level drops significantly
then you had static buildup. If not, then you are hearing atmospheric
noise and/or phase noise in the receiver. The two can be
differentiated by just disconnecting the antenna to see what kind of
noise drop you see.

Noise from static buildup is typically not static. It does not sound
like the white noise, more like a buzzing or popping, and sometimes
even like a musical tone.

A tuner, even one that is isolated by a capacitor from the antenna,
typically won't "tune" static buildup noise. The noise is basically
from small discharges caused by charge equalization. Can you use your
tuner to to "tune-in" or "tune-out" the noise from the static
discharge of a lightning strike? Mine won't. The "noise" from the
lightning strike comes through no matter where the tuner is set.

If noise in the receiver goes up and down as you operate your tuner
to find the best match between your receiver and your antenna it's
because it is actually working. It is highly unlikely that the noise
you hear going up and down is from static buildup on the antenna.

tim ab0wr

On Fri, 20 Apr 2018 20:21:25 -0500
"K9HZ" <@Doc_Bill> wrote:

I guess that then assumes you have a very simple tuner (Cap-L leg)?
No impedance transformers, inductors to ground, etc.


Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ
PJ2/K9HZ

Owner - Operator
Big Signal Ranch – K9ZC
Staunton, Illinois

Owner – Operator
Villa Grand Piton – J68HZ
Soufriere, St. Lucia W.I.
Rent it: www.VillaGrandPiton.com
Like us on Facebook!

Moderator – North American QRO Group at Groups.IO.

email: @Doc_Bill



-----Original Message-----
From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Tim
Gorman Sent: Friday, April 20, 2018 8:18 PM
To: BITX20@groups.io
Subject: Re: [BITX20] receiver overload

I agree! But if the problem here is static buildup then a tuner
won't help any more than the coax connector on the rig!

tim ab0wr

On Fri, 20 Apr 2018 17:37:45 -0500
"K9HZ" <@Doc_Bill> wrote:

That is not where you want static charges dissipating! Chokes to
ground, resistors, at the antenna. All a better place for it (the
fire) to happen.


Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ
PJ2/K9HZ

Owner - Operator
Big Signal Ranch – K9ZC
Staunton, Illinois

Owner – Operator
Villa Grand Piton – J68HZ
Soufriere, St. Lucia W.I.
Rent it: www.VillaGrandPiton.com
Like us on Facebook!

Moderator – North American QRO Group at Groups.IO.

email: @Doc_Bill



-----Original Message-----
From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Tim
Gorman Sent: Friday, April 20, 2018 4:05 PM
To: BITX20@groups.io
Subject: Re: [BITX20] receiver overload

I'm sure it happens. But not consistently. You need wind and
something to create the charge like blowing dust. If the tuner is
dissipating the charge why doesn't the rig itself do it, at least
with an unbalanced feed?

tim ab0wr

On Fri, 20 Apr 2018 08:47:00 -0500
"K9HZ" <@Doc_Bill> wrote:

Unless the antenna is picking up a static charge and the
antenna tuner is acting like an impedance to ground draining
that charge off. Don't laugh, it happens.


Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ
VP5/K9HZ PJ2/K9HZ

Owner - Operator
Big Signal Ranch – K9ZC
Staunton, Illinois

Owner – Operator
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-----Original Message-----
From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of
Tim Gorman Sent: Friday, April 20, 2018 8:42 AM
To: BITX20@groups.io
Subject: Re: [BITX20] receiver overload

Usually a tuner will increase noise, at least atmospheric
noise, as the tuner creates a match between the receiver and
the antenna. A matched antenna shouldn't "tame" the noise. If
that is actually happening then a closer look at the system
might be appropriate.

tim ab0wr



On Fri, 20 Apr 2018 11:39:39 +1000 "John Sharpe"
<johsharpe@...> wrote:

Hi all,

I just had a thought about new users of the uBitx and the
Bitx40.

I have both of these fine rigs but with my good antenna - a
ZS6BKW
<http://www.nc4fb.org/wordpress/zs6bkw-multi-band-antenna/> at
30 feet
- the receivers are swamped by noise and big signals on 40
metres.

When I tested just now a 59+ 10 signal on my IC-7300 was
unreadable on the Bitexes with the big antenna (which has a
low SWR at 40 metres) because of noise. With an antenna of
just 6 feet of wire in the shack the signal was readable (but
weak) on the Bitexes!

I usually use a tuner beween the antenna and the Bitexes -
that works fine to tame the noise. Also I have fitted an RF
control to the Bitx40 that helps quieten big signals.

But if you have lots of noise in the receiver and no tuner -
try a smaller antenna on receive (it will be no good for
transmitting). If that improves things maybe you need a tuner
or an RF control.

73s John V2VOL



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Re: show your mic

AA9GG
 

I simply replaced the element in an old replacement stock CB mike I had with the one supplied in the BitX40 kit.  Works quite well.

On Sat, Apr 21, 2018 at 12:57 PM, MAX <max@...> wrote:

Speaking of mics, I have to raise my voice almost to the level of shouting to get 5 watts out on 40 meters.  Is this normal or should I look for a problem?

 

Regards.

 

Max K 4 O D S.

 

I've Never Lost the Wonder.

 

Antique Electronics Site: http://www.angelfire.com/electronic/funwithtubes/

 

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Mvs Sarma
Sent: Saturday, April 21, 2018 7:17 AM
To: BITX20@groups.io
Subject: Re: [BITX20] show your mic

 

I had grabed a taperecorder mic with 3.5mm mono pin.
 replaced the cable with 2+shield.had a small pushed switchmounted and wired.
 repalced the 3.5mm momo pin to stereo pin. Here is a image of my mic.The pp9 battery helps to imagine the mic size.
regards
 sarma
 vu3zmv




--
Paul Mateer, AA9GG
Elan Engineering Corp.
www.elanengr.com
NAQCC 3123, SKCC 4628

Re: RTL SDR

Gerry Hull
 

No Jerry, I would connect the dongle to the 1st I-F at 45 MHz.  That way, you keep the display centered as you tune, plus you get the front end selectivity and sensitivity.

73 Gerry W1VE


On Sat, Apr 21, 2018, 1:11 PM Jerry Gaffke via Groups.Io <jgaffke=yahoo.com@groups.io> wrote:
Thanks for the info!
Sounds like the  "Experimental: HF Direct Sampling Mode" to receive frequencies 
from 500khz to 28.8mhz  is not quite ready for prime time.
Or at least, not for punters like me.
Good to know.

Jerry, KE7ER

On Sat, Apr 21, 2018 at 09:20 am, Doug W wrote:
I have the same dongle and am happy with it.  You can order it on Amazon https://www.amazon.com/RTL-SDR-Blog-RTL2832U-Software-Defined/dp/B0129EBDS2 for the same price with prime shipping to boot.  I did experiment with direct sampling but in the end broke down and bought an upconverter https://www.amazon.com/gp/product/B009LQT3G6 and later the enclosure.  It is not lost on me that all of that costs about the same as a BITX40 and by the time you throw in random connectors and what not about the same as a µBITX.  I have not tried connecting it to a Pi but using an otg adapter I have used it with an old android phone.  I haven't used it on the phone in a while but I seem to remember using the free version of SDR Touch.  Prior to having a real antenna I was using this balun https://www.amazon.com/gp/product/B00R09WHT6 and random wire with limited success and a few cheap telescoping whip antennas.
I just did a quick search and as usual Adafruit has a solid tutorial on with links to libraries https://learn.adafruit.com/freq-show-raspberry-pi-rtl-sdr-scanner?view=all
For general ideas and knowledge you can't beat https://www.rtl-sdr.com/

Re: Upgrade the software to Allard's version #radiuno #bitx40help #nano

Allard PE1NWL
 

On Sat, Apr 21, 2018 at 06:13 am, SaMa photo SaMa photo wrote:
But doing so overwrite the already loaded software, if I wanted to save a copy of the original sotware in my PC is possible?
 
If you ever want to restore the original software, you can always download it from https://github.com/afarhan/bitx40 and upload it back into your Raduino.

But the story that they say to save the calibrations and then upload them again because otherwise raduino starts from scratch?
The new software uses a different method for calibration, so you cannot use the original calibration value.
After upgrading to the new software, you must perform frequency recalibration anyway (don't worry too much about this, it's not very difficult, you can use another transceiver or AM broadcast station as a reference. See the instructions that are included with the software).
If you do not perform the recalibration, the frequency may be off by a few 100 Hz or so.

Good luck!
73 Allard PE1NWL

Firmware manual for KD8CEC rev 1.072

Rod Davis
 

Hi All,

Attached is the new firmware manual for KD8CEC firmware rev 1.072.

Feedback is certainly solicited and welcomed; please send any feedback to the email
address shown in the document, not to the bitx20 group.

Regards,

Rod KM6SN



Just received my radio. Is this good audio chip?

Gerry Hull
 

I think it is.. just m as king sure...

73 Gerry W1VE

Re: Just received my radio. Is this good audio chip?

Doug W
 

You're good.  WX are the bad ones.  Anything socketed is after the problem was discovered and fixed.

Re: receiver overload

Tim Gorman
 

That's always a possibility.

Some tuners also can act as low-pass filters or even as a parallel tuned
circuit, i.e. a bandpass filter. If the dominating noise contribution
is from a frequency-limited source such as a man-made source both could
work to lower the noise in the receiver. But I don't think this happens
very often.

tim ab0wr

On Sat, 21 Apr 2018 14:10:29 -0400
"Joe Puma" <kd2nfc@...> wrote:

I heard that when you use an antenna tuner you actually raise the
noise floor. 🤷🏻‍♂️I understand why but never heard it getting rid of
noise. Maybe the tuner provided a better ground then what you had so
yea maybe it made it seem like it reduced noise if your antenna
system is inadequate.

Joe

Re: Update to the VK2ETA variation of Ian Lee's KD8CEC uBitx software #ubitx

John (vk2eta)
 

Hello Skip,

Yes sorry, I didn't check the upload. 

I have uploaded the updated zip file in the new folder at https://groups.io/g/BITX20/files/Variations%20on%20KD8CEC%20Software%20%28by%20VK2ETA%29%20+%20ATU%20sketch/ATU%20schematics%20and%20pictures.zip

Here is a write up I did to describe the ATU: https://groups.io/g/BITX20/message/45165

I have also included here the two parts of the schematic. Part 1, the L-Network:

Control part:


Any question, ask. All the best,

73, John (VK2ETA)

Re: Coast to coast on my ubitx yesterday

Tim Gorman
 

Dave,

I would trust your meter more to tell you the swr than the actual
power.

If you have a dummy load you can hook up then this site:
http://www.ab4oj.com/test/pwrmeas.html
will give you good info on how to accurately measure your power using
your oscilloscope.

tim ab0wr


On Sat, 21 Apr 2018 10:50:28 -0700
davesters@... wrote:

Hi Tim
Yeah I do have a an oscope but the readings I gave you were from my
swr meter. Is my meter right?? It is a cheap cb meter. Still the
readings seem to close to what others have posted. Probably is my
location and atmospherics but was able to reach out and touch someone
as the old Bell ads once said. Yesterday I contacted someone in
Tucson and today it was Nantucket. 

My antenna is a homemade choked dipole resonant on 40 and 80. Hung
between trees overlooking a ravine. I use recycled RG6 from an old
residential television system. I have thought about upgrading it but
then I wonder what would be gained. 

I am running 13.8 on all circuits. I put details in my first post. 

I did not check the bias on the pa. But did go through the other
calibration steps. The bfo was not set very close. 

This is my main HF rig now and probably will be for some time. I have
thought about making the bitx40 a mobile unit.

Re: Coast to coast on my ubitx yesterday

Tim Gorman
 

Dave,

This is also a good site for how to measure output power.

http://dudleylab.com/Appnote-4-Power-tests1.pdf

tim ab0wr


On Sat, 21 Apr 2018 10:50:28 -0700
davesters@... wrote:

Hi Tim
Yeah I do have a an oscope but the readings I gave you were from my
swr meter. Is my meter right?? It is a cheap cb meter. Still the
readings seem to close to what others have posted. Probably is my
location and atmospherics but was able to reach out and touch someone
as the old Bell ads once said. Yesterday I contacted someone in
Tucson and today it was Nantucket. 

My antenna is a homemade choked dipole resonant on 40 and 80. Hung
between trees overlooking a ravine. I use recycled RG6 from an old
residential television system. I have thought about upgrading it but
then I wonder what would be gained. 

I am running 13.8 on all circuits. I put details in my first post. 

I did not check the bias on the pa. But did go through the other
calibration steps. The bfo was not set very close. 

This is my main HF rig now and probably will be for some time. I have
thought about making the bitx40 a mobile unit.