I added a new section called "sBITX" to the groups.io WIKI with the info David suggested.
--
? 73
??? Bob? KD8CGH
|
i forgot the attachments. hopefully they appear now.
|
hello friends. i hope it is ok to post this here. i made a linear amplifier, similar to wa2eby. basically two amps running in anti phase. maybe it may be helpful to someone who wants to boost the signal a bit more,
for your ham operations. i think it should work well. sugestions are welcome.
best regards,?
joao g.
|
Re: Cheap Chinese Linear LPF
On Fri, Jun 4, 2021 at 06:22 AM, Jerry Gaffke wrote:
If you need a better temperature gauge for your oven, could crush the oven light.
Already wired in with high temp tolerant wire insulation.
Keep a flashlight handy, hung from a nail in the wall near the oven.
That's a great idea :) If you don't need as fast of response in your oven, maybe you could leave the envelope on. The oven light might be able to do double duty as a light when you open the door, and temperature measurement and control when the door is closed.? An amazing invention... Advancing cooking technology born right here on this group. If you are married, though, you don't want to be pulling apart the stove for too long re-engineering and improving it. May cause unintended strife in your domestic life.? Tom, wb6b
|
Shirley, given that we are looking for a wide bandwidth, we wouldn't need much of matching. I just took the first eight off the smd strip and they worked!
On Fri 4 Jun, 2021, 10:32 PM Shirley Dulcey KE1L, < mark@...> wrote: I was eyeing those 40 MHz fundamental mode crystals that you can buy from Digi-Key and Mouser. The prices are reasonable, under 30 cents. Looks like you've now done some of the work to try them out. I do wonder how many it will be necessary to buy to get a properly matched set.
I've been thinking of trying my first sBITX build as a modular one, doing each section of the circuit on a separate board. (Each of the two KISS mixers on a board, the crystal filter on another, and so forth.) Miniaturizing everything onto a single board is less important for something with a 7" touchscreen because it's never going to be small anyway. But I'm also looking forward to seeing the finished board design.
On Fri, Jun 4, 2021 at 10:42 AM Ashhar Farhan < farhanbox@...> wrote: I am reassigning pins to simplify the pcb layout. So, please hold on for a week (until I get my pcbs) before starting to make the sbitx. I also managed a 30 khz wide filter on 40 mhz (whoa!) Which means, we will be able to cover the entire HF band.
On Fri 4 Jun, 2021, 7:53 PM David Forrest, < drf5na@...> wrote: The??video,?
the??link to the googledoc presentation materials and
the??repository, with the code chunks like
rx_process() :??
are all enlightening.
|
Re: Receiver working, sensitivity issues?
I think we are addressing multiple topics now. The paradigm of the small loop versus a longer length of wire as a receive only antenna. For the latter wire diameter less critical.??
Simian don't be discouraged as you learn and explore. I hope you are receiving with your ubitx soon. A longer wire for receiving is easier to get working first, while you continue to consider a loop. I have qso with a few folk who used a small loop, but they always have substantial conductor and a sharp tuning network.?
Curt
|
I was eyeing those 40 MHz fundamental mode crystals that you can buy from Digi-Key and Mouser. The prices are reasonable, under 30 cents. Looks like you've now done some of the work to try them out. I do wonder how many it will be necessary to buy to get a properly matched set.
I've been thinking of trying my first sBITX build as a modular one, doing each section of the circuit on a separate board. (Each of the two KISS mixers on a board, the crystal filter on another, and so forth.) Miniaturizing everything onto a single board is less important for something with a 7" touchscreen because it's never going to be small anyway. But I'm also looking forward to seeing the finished board design.
On Fri, Jun 4, 2021 at 10:42 AM Ashhar Farhan < farhanbox@...> wrote: I am reassigning pins to simplify the pcb layout. So, please hold on for a week (until I get my pcbs) before starting to make the sbitx. I also managed a 30 khz wide filter on 40 mhz (whoa!) Which means, we will be able to cover the entire HF band.
On Fri 4 Jun, 2021, 7:53 PM David Forrest, < drf5na@...> wrote: The??video,?
the??link to the googledoc presentation materials and
the??repository, with the code chunks like
rx_process() :??
are all enlightening.
|
?David? At 11 MHz, it is difficult to build a 10 khz filter without desoldering all the caps and the matching transformers.? However, if you are okay with the 3 Khz bandwidth, then it can be used unmodified
On Fri 4 Jun, 2021, 9:50 PM David Forrest, < drf5na@...> wrote: Couldn't sBITX do a 10kHz wide window with a relatively unmodified uBITX without the 27MHz or 40MHz IF mods?
|
Couldn't sBITX do a 10kHz wide window with a relatively unmodified uBITX without the 27MHz or 40MHz IF mods?
|
Perhaps a README.md file like this would be good for the repository: # sBITX -- An open source SDR that you can hack See these resources for more information: ?-- Ashhar Farhan's presentation video * ? -- link to the googledoc presentation materials * ?-- this code repository *? /g/BITX20/topic/83191173?-- discussion thread # Building on the Raspberry Pi: ? ? apt install fftw3? libgtk-3-dev?libasound2-dev?libncurses-dev?wiringpi
? ./build sbitx
|
I am reassigning pins to simplify the pcb layout. So, please hold on for a week (until I get my pcbs) before starting to make the sbitx. I also managed a 30 khz wide filter on 40 mhz (whoa!) Which means, we will be able to cover the entire HF band.
On Fri 4 Jun, 2021, 7:53 PM David Forrest, < drf5na@...> wrote: The??video,?
the??link to the googledoc presentation materials and
the??repository, with the code chunks like
rx_process() :??
are all enlightening.
|
The??video,?
the??link to the googledoc presentation materials and
the??repository, with the code chunks like
rx_process() :??
are all enlightening.
|
Re: Cheap Chinese Linear LPF
Interesting.
Most metals have about the same temperature coefficient of resistivity as tungston:
? ??
Must be a very fine filament so it changes temperature quickly when exposed to air of a different temperature.
A strand of 0000 (very fine) steel wool would probably work.
The light bulb filament has the advantage of already being in a convenient holder.
If you need a better temperature gauge for your oven, could crush the oven light.
Already wired in with high temp tolerant wire insulation.
Keep a flashlight handy, hung from a nail in the wall near the oven.
Jerry, KE7ER
toggle quoted message
Show quoted text
On Fri, Jun 4, 2021 at 12:20 AM, Tom, wb6b wrote:
One more interesting use of crushed lightbulbs. A person who "served" on Antartica for a year gave a talk at a club meeting. One on the experiments measured the outside temperature at an remote station using 100 watt light bulbs with the envelopes broken off. For some reason they needed very fast response time, and the light bulb filaments did the job. ?
|
Hi Gerald
I have built a somewhat similar loop with 2.6m of half inch heliax and a very small capacitor (5pf to 40pf), aiming the top bands. The problem is that tuning is very, very sensitive in that range and I am importing a reduction vernier to improve that.
Having a single loop for the whole band might not be very efficient. I built a second loop, with 2.4m for using on 10m, and a third, 4m loop aiming to improve the efficiency 40m band. All of the loops uses the same capacitor, and some extra parallel capacitors.
All in all, building a loop is a fun and rewarding project! Enjoy the trip!
Rafael PU1OWL
|
Re: Cheap Chinese Linear LPF
On Thu, Jun 3, 2021 at 06:09 PM, kx4om wrote:
Are you familiar with the Youtube channel "Applied Science"? The engineer who runs it has some interesting videos:
Yes, that is one of my favorite you-tubers. I like how he used crushed light bulbs as a cathode in his spectrometer. I have a surplus Pirani vacuum gauge that I'm using now, but am interested in seeing how crushed light bulbs might work for making a DIY vacuum gauge.? Here are a couple of other channels I like: BigClive Fran Lab Tech Ingredients Applied Science Technology Connections Tim Hunkin (Great... Now when I want to find one of these channels all I need to do is refer to the handy bookmarks, above.) There are several physics and math channels I like also. When I switched to doing software engineering after many many years of just doing ones and zeros, I need as much refresher as I possibility can get.? One more interesting use of crushed lightbulbs. A person who "served" on Antartica for a year gave a talk at a club meeting. One on the experiments measured the outside temperature at an remote station using 100 watt light bulbs with the envelopes broken off. For some reason they needed very fast response time, and the light bulb filaments did the job. ? Tom, wb6b
|
Right. Thanks Farhan. And have a good weekend!
Rafael
toggle quoted message
Show quoted text
On 6/4/21 9:15 AM, Ashhar Farhan wrote: It is too early to think about that.
The sbitx is an add-on for existing radios with a little bit of
modification to the crystal filter. I am designing a new radio to go
with it.?
But, the ubitx, as a product, will continue as an all analog radio.
- f
On Fri, Jun 4, 2021 at 11:15 AM Rafael Diniz <rafael@...
<mailto:rafael@...>> wrote:
Dear Farhan,
Do you plan to "deploy" sBITX as uBitx, with pre-assembled selling and
so on?
Thanks,
Rafael Diniz
On 6/2/21 5:01 PM, Ashhar Farhan wrote:
> Oops, I send to the wrong?email addy. Sorry about that. this was
meant
> for Bill.
> - f
>
> On Wed, Jun 2, 2021 at 7:28 PM Ashhar Farhan via groups.io
<>
> < <>>
<farhanbox@... <mailto:[email protected]>
> <mailto:[email protected] <mailto:[email protected]>>> wrote:
>
>? ? ?Bill,
>? ? ?The only time I used gilbert cell (NE602) was to build the
21 MHz
>? ? ?to 29 MHz transponder. The nearest station would be at least 500
>? ? ?KM away and the Yagis of the bad boys would be pointing
along the
>? ? ?ground towards each other. Isn't it an active mixer?
>? ? ?The KISS mixer is a passive mixer. The FETs are used as
switches,
>? ? ?not as amplifiers. The big deal is this: In a diode mixer, the
>? ? ?diodes are turned on by the switching current that flows along
>? ? ?with signal current through the same paths. In the FET switching
>? ? ?mixer, there is no switching current, and the switch is
turned on
>? ? ?by driving the gate very hard and almost instantaneously - that
>? ? ?makes it so resilient?to any reflected current coming back from
>? ? ?the filter side.?
>? ? ?SDR aside, the KISS mixer, theoretically consumes zero drive
>? ? ?power. It just needs a square-wave voltage to switch. It
makes for
>? ? ?a great analog front-end. That's what I tried with the Minima, I
>? ? ?should have used multiple band pass filters and added CW and
AGC,
>? ? ?it would have made a great radio. I might still do that!
>? ? ?I just got a strip of 100 40 MHz, fundamental crystals. Let
me see
>? ? ?if I can hammer out a filter with them. If it works, then I can
>? ? ?extend the sBITX to full 30 Mhz coverage.
>? ? ?I must read up on the Gilbert cell, EMRFD has devoted quite
a few
>? ? ?pages to it.
>? ? ?- f
>
>? ? ?On Wed, Jun 2, 2021 at 3:22 PM Rafael Diniz
>? ? ?<rafael@... <mailto:rafael@...>
<mailto:rafael@... <mailto:rafael@...>>>
wrote:
>
>? ? ? ? ?One question: Which is the transmit and receive bandwidth of
>? ? ? ? ?the sBITX?
>
>? ? ? ? ?How to buy or build one? (Without the Raspberry Pi, as the
>? ? ? ? ?need for
>? ? ? ? ?processing I have is much higher of what the Raspberry can
>? ? ? ? ?provide - I
>? ? ? ? ?need at least AVX2 4th gen Intel chip for ML purposes).
>
>? ? ? ? ?Thanks,
>? ? ? ? ?Rafael Diniz
>
>? ? ? ? ?On 6/2/21 12:04 PM, Rafael Diniz wrote:
>? ? ? ? ?> Thanks a lot!
>? ? ? ? ?>
>? ? ? ? ?> Reading the names of Farhan and Phil Karn makes me
shiver! Wow!!
>? ? ? ? ?>
>? ? ? ? ?> You are the ones!!!
>? ? ? ? ?>
>? ? ? ? ?> Rafael
>? ? ? ? ?>
>? ? ? ? ?> On 6/2/21 11:32 AM, Shirley Dulcey KE1L wrote:
>? ? ? ? ?>> I should?add that it's a transceiver design, not just a
>? ? ? ? ?receiver.
>? ? ? ? ?The
>? ? ? ? ?>> DSP is done by a Raspberry Pi 4. The talk first
presents a
>? ? ? ? ?>> modification of the uBITX, then goes on to show a new
>? ? ? ? ?design that
>? ? ? ? ?>> Farhan is working on.
>? ? ? ? ?>>
>? ? ? ? ?>> On Wed, Jun 2, 2021 at 4:30 AM Shirley Dulcey KE1L via
>? ? ? ? ?groups.io <> <
<>>
>? ? ? ? ?>> < <>
< <>>>
>? ? ? ? ?<mark@...
<mailto:[email protected]> <mailto:[email protected]
<mailto:[email protected]>>
>? ? ? ? ?>> <mailto:[email protected]
<mailto:[email protected]>
>? ? ? ? ?<mailto:[email protected]
<mailto:[email protected]>>>> wrote:
>? ? ? ? ?>>
>? ? ? ? ?>>? ? ?The sBITX is a simple hybrid SDR; it uses
a conversion
>? ? ? ? ?to 27 MHz,
>? ? ? ? ?>>? ? ?a crystal filter there, and then downconversion to a
>? ? ? ? ?near-zero IF
>? ? ? ? ?>>? ? ?where the signal goes into an audio ADC.
>? ? ? ? ?>>
>? ? ? ? ?>>? ? ?Here's a link to Farhan's talk about it at
>? ? ? ? ?>>? ? ?FDIM:?
<>
>? ? ? ? ?<
<>>
>? ? ? ? ?>>? ? ?<
<>
>? ? ? ? ?<
<>>>
>? ? ? ? ?>>
>? ? ? ? ?>>
>? ? ? ? ?>>? ? ?On Wed, Jun 2, 2021 at 2:07 AM Rafael Diniz
>? ? ? ? ?>>? ? ?<rafael@...
<mailto:rafael@...> <mailto:rafael@...
<mailto:rafael@...>>
>? ? ? ? ?<mailto:rafael@...
<mailto:rafael@...>
>? ? ? ? ?<mailto:rafael@...
<mailto:rafael@...>>>> wrote:
>? ? ? ? ?>>
>? ? ? ? ?>>? ? ? ? ?Hi everybody,
>? ? ? ? ?>>
>? ? ? ? ?>>? ? ? ? ?I'm sorry, but after many messages, I also wanna
>? ? ? ? ?know what
>? ? ? ? ?>>? ? ? ? ?sBITX is.
>? ? ? ? ?>>? ? ? ? ?This link does not give any
clue. Any link with the
>? ? ? ? ?actual
>? ? ? ? ?>>? ? ? ? ?video of
>? ? ? ? ?>>? ? ? ? ?Farhan speech?
>? ? ? ? ?>>
>? ? ? ? ?>>? ? ? ? ?Thanks,
>? ? ? ? ?>>? ? ? ? ?Rafael
>? ? ? ? ?>>
>? ? ? ? ?>>? ? ? ? ?On 6/1/21 8:41 PM, Jerry Gaffke via groups.io
<>
>? ? ? ? ?< <>>
>? ? ? ? ?>>? ? ? ? ?< <>
< <>>> wrote:
>? ? ? ? ?>>? ? ? ? ?> See?
?/g/BITX20/topic/82011726
</g/BITX20/topic/82011726>
>? ? ? ? ?</g/BITX20/topic/82011726
</g/BITX20/topic/82011726>>
>? ? ? ? ?>>? ? ? ? ?</g/BITX20/topic/82011726
</g/BITX20/topic/82011726>
>? ? ? ? ?</g/BITX20/topic/82011726
</g/BITX20/topic/82011726>>>
>? ? ? ? ?>>? ? ? ? ?> </g/BITX20/topic/82011726
</g/BITX20/topic/82011726>
>? ? ? ? ?</g/BITX20/topic/82011726
</g/BITX20/topic/82011726>>
>? ? ? ? ?>>? ? ? ? ?</g/BITX20/topic/82011726
</g/BITX20/topic/82011726>
>? ? ? ? ?</g/BITX20/topic/82011726
</g/BITX20/topic/82011726>>>>
>? ? ? ? ?>>? ? ? ? ?>
>? ? ? ? ?>>? ? ? ? ?> On Tue, Jun 1, 2021 at 08:42 AM, allen west
wrote:
>? ? ? ? ?>>? ? ? ? ?>
>? ? ? ? ?>>? ? ? ? ?>? ? ?I guess I have not been following as
closely as I
>? ? ? ? ?>>? ? ? ? ?should.? But
>? ? ? ? ?>>? ? ? ? ?>? ? ?what is this sBITX?? When I joined this
group
>? ? ? ? ?it was for
>? ? ? ? ?>>? ? ? ? ?the BITX
>? ? ? ? ?>>? ? ? ? ?>? ? ?20, 40
or the uBITX. ?
>? ? ? ? ?>>? ? ? ? ?>? ? ??
>? ? ? ? ?>>? ? ? ? ?>
>? ? ? ? ?>>? ? ? ? ?>
>? ? ? ? ?>>
>? ? ? ? ?>>
>? ? ? ? ?>>
>? ? ? ? ?>>
>? ? ? ? ?>>
>? ? ? ? ?>>
>? ? ? ? ?>>
>? ? ? ? ?>
>? ? ? ? ?>
>? ? ? ? ?>
>? ? ? ? ?>
>? ? ? ? ?>
>
>
>
>
>
>
>
|
It is too early to think about that. The sbitx is an add-on for existing radios with a little bit of modification to the crystal filter. I am designing a new radio to go with it.? But, the ubitx, as a product, will continue as an all analog radio. - f
On Fri, Jun 4, 2021 at 11:15 AM Rafael Diniz < rafael@...> wrote: Dear Farhan,
Do you plan to "deploy" sBITX as uBitx, with pre-assembled selling and
so on?
Thanks,
Rafael Diniz
On 6/2/21 5:01 PM, Ashhar Farhan wrote:
> Oops, I send to the wrong?email addy. Sorry about that. this was meant
> for Bill.
> - f
>
> On Wed, Jun 2, 2021 at 7:28 PM Ashhar Farhan via
> <> <farhanbox=[email protected]
> <mailto:[email protected]>> wrote:
>
>? ? ?Bill,
>? ? ?The only time I used gilbert cell (NE602) was to build the 21 MHz
>? ? ?to 29 MHz transponder. The nearest station would be at least 500
>? ? ?KM away and the Yagis of the bad boys would be pointing along the
>? ? ?ground towards each other. Isn't it an active mixer?
>? ? ?The KISS mixer is a passive mixer. The FETs are used as switches,
>? ? ?not as amplifiers. The big deal is this: In a diode mixer, the
>? ? ?diodes are turned on by the switching current that flows along
>? ? ?with signal current through the same paths. In the FET switching
>? ? ?mixer, there is no switching current, and the switch is turned on
>? ? ?by driving the gate very hard and almost instantaneously - that
>? ? ?makes it so resilient?to any reflected current coming back from
>? ? ?the filter side.?
>? ? ?SDR aside, the KISS mixer, theoretically consumes zero drive
>? ? ?power. It just needs a square-wave voltage to switch. It makes for
>? ? ?a great analog front-end. That's what I tried with the Minima, I
>? ? ?should have used multiple band pass filters and added CW and AGC,
>? ? ?it would have made a great radio. I might still do that!
>? ? ?I just got a strip of 100 40 MHz, fundamental crystals. Let me see
>? ? ?if I can hammer out a filter with them. If it works, then I can
>? ? ?extend the sBITX to full 30 Mhz coverage.
>? ? ?I must read up on the Gilbert cell, EMRFD has devoted quite a few
>? ? ?pages to it.
>? ? ?- f
>
>? ? ?On Wed, Jun 2, 2021 at 3:22 PM Rafael Diniz
>? ? ?<rafael@... <mailto:rafael@...>> wrote:
>
>? ? ? ? ?One question: Which is the transmit and receive bandwidth of
>? ? ? ? ?the sBITX?
>
>? ? ? ? ?How to buy or build one? (Without the Raspberry Pi, as the
>? ? ? ? ?need for
>? ? ? ? ?processing I have is much higher of what the Raspberry can
>? ? ? ? ?provide - I
>? ? ? ? ?need at least AVX2 4th gen Intel chip for ML purposes).
>
>? ? ? ? ?Thanks,
>? ? ? ? ?Rafael Diniz
>
>? ? ? ? ?On 6/2/21 12:04 PM, Rafael Diniz wrote:
>? ? ? ? ?> Thanks a lot!
>? ? ? ? ?>
>? ? ? ? ?> Reading the names of Farhan and Phil Karn makes me shiver! Wow!!
>? ? ? ? ?>
>? ? ? ? ?> You are the ones!!!
>? ? ? ? ?>
>? ? ? ? ?> Rafael
>? ? ? ? ?>
>? ? ? ? ?> On 6/2/21 11:32 AM, Shirley Dulcey KE1L wrote:
>? ? ? ? ?>> I should?add that it's a transceiver design, not just a
>? ? ? ? ?receiver.
>? ? ? ? ?The
>? ? ? ? ?>> DSP is done by a Raspberry Pi 4. The talk first presents a
>? ? ? ? ?>> modification of the uBITX, then goes on to show a new
>? ? ? ? ?design that
>? ? ? ? ?>> Farhan is working on.
>? ? ? ? ?>>
>? ? ? ? ?>> On Wed, Jun 2, 2021 at 4:30 AM Shirley Dulcey KE1L via
>? ? ? ? ? <>
>? ? ? ? ?>> < <>>
>? ? ? ? ?<mark=[email protected] <mailto:[email protected]>
>? ? ? ? ?>> <mailto:[email protected]
>? ? ? ? ?<mailto:[email protected]>>> wrote:
>? ? ? ? ?>>
>? ? ? ? ?>>? ? ?The sBITX is a simple hybrid SDR; it uses
a conversion
>? ? ? ? ?to 27 MHz,
>? ? ? ? ?>>? ? ?a crystal filter there, and then downconversion to a
>? ? ? ? ?near-zero IF
>? ? ? ? ?>>? ? ?where the signal goes into an audio ADC.
>? ? ? ? ?>>
>? ? ? ? ?>>? ? ?Here's a link to Farhan's talk about it at
>? ? ? ? ?>>? ? ?FDIM:?
>? ? ? ? ?<>
>? ? ? ? ?>>? ? ?<
>? ? ? ? ?<>>
>? ? ? ? ?>>
>? ? ? ? ?>>
>? ? ? ? ?>>? ? ?On Wed, Jun 2, 2021 at 2:07 AM Rafael Diniz
>? ? ? ? ?>>? ? ?<rafael@... <mailto:rafael@...>
>? ? ? ? ?<mailto:rafael@...
>? ? ? ? ?<mailto:rafael@...>>> wrote:
>? ? ? ? ?>>
>? ? ? ? ?>>? ? ? ? ?Hi everybody,
>? ? ? ? ?>>
>? ? ? ? ?>>? ? ? ? ?I'm sorry, but after many messages, I also wanna
>? ? ? ? ?know what
>? ? ? ? ?>>? ? ? ? ?sBITX is.
>? ? ? ? ?>>? ? ? ? ?This link does not give any
clue. Any link with the
>? ? ? ? ?actual
>? ? ? ? ?>>? ? ? ? ?video of
>? ? ? ? ?>>? ? ? ? ?Farhan speech?
>? ? ? ? ?>>
>? ? ? ? ?>>? ? ? ? ?Thanks,
>? ? ? ? ?>>? ? ? ? ?Rafael
>? ? ? ? ?>>
>? ? ? ? ?>>? ? ? ? ?On 6/1/21 8:41 PM, Jerry Gaffke via
>? ? ? ? ?<>
>? ? ? ? ?>>? ? ? ? ?< <>> wrote:
>? ? ? ? ?>>? ? ? ? ?> See? ?/g/BITX20/topic/82011726
>? ? ? ? ?</g/BITX20/topic/82011726>
>? ? ? ? ?>>? ? ? ? ?</g/BITX20/topic/82011726
>? ? ? ? ?</g/BITX20/topic/82011726>>
>? ? ? ? ?>>? ? ? ? ?> </g/BITX20/topic/82011726
>? ? ? ? ?</g/BITX20/topic/82011726>
>? ? ? ? ?>>? ? ? ? ?</g/BITX20/topic/82011726
>? ? ? ? ?</g/BITX20/topic/82011726>>>
>? ? ? ? ?>>? ? ? ? ?>
>? ? ? ? ?>>? ? ? ? ?> On Tue, Jun 1, 2021 at 08:42 AM, allen west wrote:
>? ? ? ? ?>>? ? ? ? ?>
>? ? ? ? ?>>? ? ? ? ?>? ? ?I guess I have not been following as closely as I
>? ? ? ? ?>>? ? ? ? ?should.? But
>? ? ? ? ?>>? ? ? ? ?>? ? ?what is this sBITX?? When I joined this group
>? ? ? ? ?it was for
>? ? ? ? ?>>? ? ? ? ?the BITX
>? ? ? ? ?>>? ? ? ? ?>? ? ?20, 40
or the uBITX. ?
>? ? ? ? ?>>? ? ? ? ?>? ? ??
>? ? ? ? ?>>? ? ? ? ?>
>? ? ? ? ?>>? ? ? ? ?>
>? ? ? ? ?>>
>? ? ? ? ?>>
>? ? ? ? ?>>
>? ? ? ? ?>>
>? ? ? ? ?>>
>? ? ? ? ?>>
>? ? ? ? ?>>
>? ? ? ? ?>
>? ? ? ? ?>
>? ? ? ? ?>
>? ? ? ? ?>
>? ? ? ? ?>
>
>
>
>
>
>
>
|
Dear Farhan, Do you plan to "deploy" sBITX as uBitx, with pre-assembled selling and so on? Thanks, Rafael Diniz On 6/2/21 5:01 PM, Ashhar Farhan wrote: Oops, I send to the wrong?email addy. Sorry about that. this was meant
for Bill.
- f
On Wed, Jun 2, 2021 at 7:28 PM Ashhar Farhan via groups.io
<> <farhanbox@...
<mailto:[email protected]>> wrote:
Bill,
The only time I used gilbert cell (NE602) was to build the 21 MHz
to 29 MHz transponder. The nearest station would be at least 500
KM away and the Yagis of the bad boys would be pointing along the
ground towards each other. Isn't it an active mixer?
The KISS mixer is a passive mixer. The FETs are used as switches,
not as amplifiers. The big deal is this: In a diode mixer, the
diodes are turned on by the switching current that flows along
with signal current through the same paths. In the FET switching
mixer, there is no switching current, and the switch is turned on
by driving the gate very hard and almost instantaneously - that
makes it so resilient?to any reflected current coming back from
the filter side.?
SDR aside, the KISS mixer, theoretically consumes zero drive
power. It just needs a square-wave voltage to switch. It makes for
a great analog front-end. That's what I tried with the Minima, I
should have used multiple band pass filters and added CW and AGC,
it would have made a great radio. I might still do that!
I just got a strip of 100 40 MHz, fundamental crystals. Let me see
if I can hammer out a filter with them. If it works, then I can
extend the sBITX to full 30 Mhz coverage.
I must read up on the Gilbert cell, EMRFD has devoted quite a few
pages to it.
- f
On Wed, Jun 2, 2021 at 3:22 PM Rafael Diniz
<rafael@... <mailto:rafael@...>> wrote:
One question: Which is the transmit and receive bandwidth of
the sBITX?
How to buy or build one? (Without the Raspberry Pi, as the
need for
processing I have is much higher of what the Raspberry can
provide - I
need at least AVX2 4th gen Intel chip for ML purposes).
Thanks,
Rafael Diniz
On 6/2/21 12:04 PM, Rafael Diniz wrote:
> Thanks a lot!
>
> Reading the names of Farhan and Phil Karn makes me shiver! Wow!!
>
> You are the ones!!!
>
> Rafael
>
> On 6/2/21 11:32 AM, Shirley Dulcey KE1L wrote:
>> I should?add that it's a transceiver design, not just a
receiver.
The
>> DSP is done by a Raspberry Pi 4. The talk first presents a
>> modification of the uBITX, then goes on to show a new
design that
>> Farhan is working on.
>>
>> On Wed, Jun 2, 2021 at 4:30 AM Shirley Dulcey KE1L via
groups.io <>
>> < <>>
<mark@... <mailto:[email protected]>
>> <mailto:[email protected]
<mailto:[email protected]>>> wrote:
>>
>>? ? ?The sBITX is a simple hybrid SDR; it uses a conversion to 27 MHz,
>>? ? ?a crystal filter there, and then downconversion to a
near-zero IF
>>? ? ?where the signal goes into an audio ADC.
>>
>>? ? ?Here's a link to Farhan's talk about it at
>>? ? ?FDIM:?
<>
>>? ? ?<
<>>
>>
>>
>>? ? ?On Wed, Jun 2, 2021 at 2:07 AM Rafael Diniz
>>? ? ?<rafael@... <mailto:rafael@...>
<mailto:rafael@...
<mailto:rafael@...>>> wrote:
>>
>>? ? ? ? ?Hi everybody,
>>
>>? ? ? ? ?I'm sorry, but after many messages, I also wanna
know what
>>? ? ? ? ?sBITX is.
>>? ? ? ? ?This link does not give any clue. Any link with the actual
>>? ? ? ? ?video of
>>? ? ? ? ?Farhan speech?
>>
>>? ? ? ? ?Thanks,
>>? ? ? ? ?Rafael
>>
>>? ? ? ? ?On 6/1/21 8:41 PM, Jerry Gaffke via groups.io
<>
>>? ? ? ? ?< <>> wrote:
>>? ? ? ? ?> See? ?/g/BITX20/topic/82011726
</g/BITX20/topic/82011726>
>>? ? ? ? ?</g/BITX20/topic/82011726
</g/BITX20/topic/82011726>>
>>? ? ? ? ?> </g/BITX20/topic/82011726
</g/BITX20/topic/82011726>
>>? ? ? ? ?</g/BITX20/topic/82011726
</g/BITX20/topic/82011726>>>
>>? ? ? ? ?>
>>? ? ? ? ?> On Tue, Jun 1, 2021 at 08:42 AM, allen west wrote:
>>? ? ? ? ?>
>>? ? ? ? ?>? ? ?I guess I have not been following as closely as I
>>? ? ? ? ?should.? But
>>? ? ? ? ?>? ? ?what is this sBITX?? When I joined this group
it was for
>>? ? ? ? ?the BITX
>>? ? ? ? ?>? ? ?20, 40 or the uBITX. ? >>? ? ? ? ?>? ? ??
>>? ? ? ? ?>
>>? ? ? ? ?>
>>
>>
>>
>>
>>
>>
>>
>
>
>
>
>
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where was the list tom
dave k7da
On 6/3/2021 8:05 AM, Tom, wb6b wrote:
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Show quoted text
On Tue, Jun 1, 2021 at 07:29 AM, Ashhar Farhan wrote:
I thought hard about current consumption. "We are no
longer in Kansas".
I saw an article a little while back. The article was a
comprehensive list of reference sites, articles, books and data
that you should clone onto a Raspberry Pi and place in a sealed
metal box, so if an apocalypse?happens you have everything you
need for reference to start over again. (I suppose you should put
a keyboard, some kind of display and versatile power source in
there, too.)
This could be a good idea if you are operating from a remote
mountain top to use a Raspberry Pi to control your radio so you
have everything you need information wise should things go bad
while while you are away from civilization. :)
Tom, wb6b
|
Re: Receiver working, sensitivity issues?
my 170m loop is made from 3mm antenna wire ... a thin wire from a
tvset wont work
dg9bfc sigi
Am 04.06.2021 um 04:32 schrieb masch57:
toggle quoted message
Show quoted text
Wire, yes, and don't be picky about it.? Old CRT TVs or monitors
have deflection coils with lots of thin wire that is free and
nearly invisible.? Push it through the screen in your window and
far out into the world.? Then scrape the end of it (it's covered
in enamel) and hook it up to one terminal of your antenna
connector.? Hook up the other terminal to a ground, or just more
wire, going somewhere else.? Try different stuff.? Did this as a
kid, still doing now, and even transmitting on it using a cheap
antenna tuner.
|
Bob Benedict, KD8CGH
Shirley Dulcey KE1L
Rafael Pinto [PU1OWL]