Dear Jerry,
I had the same issue.
What I did was to remove the Nano from the socket in Raduino and connect it directly to the Laptop with USB cable.
Selected the right com port , Board: Arduino Nano, Processor: Atmega 328P( old bootloader ), Programmer: AVR ISP.
This worked for me all the time every time.
73,
Nitin - VU3GAO
|
Re: Power for a UBitz v6
#power
For a battery powered shack and field use, OH8STN/Julian's videos and blog are excellent.
His main focus is QRP field work for 'grid down' comms.? He's using some high-end flexible solar panels in the field, but his batteries are homebrewed from LiFePO4 and rival the commercial "solar generators" for much less money.
He's found the Genasun charge controllers to be robust and RF quiet.??
This blog post and three video set shows his design overview, build, and update process for a 12V 45 Ah battery suitable for shack and field use.
73, Andy
|
Yes, Raj, I remember that.. The raspberry pi zero is probably running out on the FFT routines. The UI thread does nothing until something is physically? touched or changed.? One option is to use the FFT function of the raspberry pi GPU. The library is already on the? new distributions. - f
I've built very similar circuits.. standard low noise input preamp for
magnetic cartridge in vinyl record players. Only
difference is that there are some additional components for RIAA
compensation.
You may remember I mentioned you try this many moons ago! in place of
Q70.
Cheers Farhan
Raj
At 30/07/2021, you wrote:
I am glad that it works. The
audio amplifier for sbitx class of radios needs to have a strong signal
handlig capabilities as well. I suggest you hear over to
and duplicate the audio fba
amplifier. It is a simple but brilliant design. Thats whats in the sbitx
now as well. In fact, I pushed wes to get it on the
website!
|
I've built very similar circuits.. standard low noise input preamp for
magnetic cartridge in vinyl record players. Only
difference is that there are some additional components for RIAA
compensation.
You may remember I mentioned you try this many moons ago! in place of
Q70.
Cheers Farhan
Raj
At 30/07/2021, you wrote:
toggle quoted message
Show quoted text
I am glad that it works. The
audio amplifier for sbitx class of radios needs to have a strong signal
handlig capabilities as well. I suggest you hear over to
and duplicate the audio fba
amplifier. It is a simple but brilliant design. Thats whats in the sbitx
now as well. In fact, I pushed wes to get it on the
website!
|
Re: Power for a UBitz v6
#power
Best source for info like that is a manufacturers data sheet. ?Second best is a comparable gel cell battery data sheet. ? is my goto. ?BTW, that is likely 3.75 or 4 A-h or Amp-hours. ?It could put out 200mA for 20 hours. ?A-h ratings are typically given for the 20 hour rate. ?A higher amperage draw would mean less total A-h. The data sheet would have a curve showing this. ?
The easiest charging method to implement is called float charging. ?it just needs a constant voltage / constant current supply. A bench supply could do it or a number of up, down, up-down DC-DC switching converters available on Amazon, e-Bay or elsewhere can do it. ?Make sure the float voltage is set exactly to the battery spec sheet. ?Check that the charger doesn¡¯t drain current from the battery when no input power is supplied. ?If it does, put a diode between and adjust the charge voltage after the diode.
toggle quoted message
Show quoted text
On Jul 29, 2021, at 10:22 PM, David Barber < wd8ajq@...> wrote:
I was given a 12 volt jell cell battery. It is either 3.75 or 4 amps. What volts and amps I need to charge the jell cell? How long will the battery take to charge? Thanks in advance! - Dave WD8AJQ
|
Re: Power for a UBitz v6
#power
Hello to all:
I was given a 12 volt jell cell battery. It is either 3.75 or 4 amps. What volts and amps I need to charge the jell cell? How long will the battery take to charge? Thanks in advance! - Dave WD8AJQ
toggle quoted message
Show quoted text
|
Re: uBitx V6 - Transmit logic in firmware
Now that my V6 is modded to my liking the only other thing I wish it had was an AM mode.? This would make for a true general coverage communication receiver.? I actually ran into somebody working AM on 40m a while back.
73,
Justin B.
KI5GKD
|
I am glad that it works. The audio amplifier for sbitx class of radios needs to have a strong signal handlig capabilities as well. I suggest you hear over to and duplicate the audio fba amplifier. It is a simple but brilliant design. Thats whats in the sbitx now as well. In fact, I pushed wes to get it on the website!
Hi Ashhar,
After solving some hardware issues on my little WM8731 board I
finally made it work, first with the alsa-utils then with sbitx
software itself, hence a little "eureka" for this successful proof
of concept.?
The WM8731 chip is indeed rather touchy (I had some bad
experiences in the past driving it from a STM32 chip) and since
its internal registers are write only, there is no way to check
their content.? Luckily, the series resistors in the I2S and I2C
lines proofed quite helpful.? Further, it took me a while to
understand that the Si5351 is controlled by its own soft I2C bus.?
Now the vfo and bfo generator module is also functional.? See
photo 6177, the toroids (2/1 rf transformers) in the clock lines
are an attempt to mach de outputs of the Si5351 to 50Ohm for the
mixers.?
Finally, I was able to "repurpose" an home build receiver front
end (from a previous project) out of my junk box to complete the
sbitx hardware, at least as a receiver.? This module (see photo
6178) contains a 30MHz LPF, a SBL-1 type mixer, a rf amplifier, a
45MHz 4 pole crystal BPF (Golledge 45G15B1), a 2nd rf amplifier
and a 2nd SBL-1 type mixer.? The output of the 2nd mixer is
provisionally send directly to the line input of the WM8731.? The
overall gain of this front end is about 10dB, too little for the
work (I will later add some amplification at 24kHz).? Also the
45G15B1 is not ideal for this application (the 15kHz bandwidth is
too small and stop bands do not fall fast enough), but it will do
for this proof of concept.?
See photo 6176 for a complete view of the set up, not very
practical using the RasPi-400 ?.?? See photo 6175, a screenshot
with the spectrum and waterfall when injecting a -60dBm RTTY
signal at 7053kHz, a really fantastic view !.?
The WM8731 annex Si5351 board is fully powered from the Raspi-400
(5V & 3.3V), the front end is powered separately from a 12V
source.? Again it it is just a proof of concept.?
I didn't modify the sbitx software (yet), safe for changing the
bfo frequency to 45024000. I intent to further hack the sbitx
software step by step wise so that it fits my purpose, i.e. having
a headless transceiver. I'll keep you posted.?
Obviously I do not intend to keep the SBL-1 mixers and 45G15B1
filter in a final design, I will rather wait patiently for
whatever hardware will be made available.? Though I may decide to
design my own hardware version of the sbitx. ??
I attempted to run this setup on a RasPi-Zero, it does not work.?
A cw signal comes out like that of a broken school bell, i.e. some
10ms of tone followed by 20ms of silence and so on.? Obviously the
RasPi-Zero is not powerful enough to run the full sbitx software,
a bit astonishing, the RasPi-zero being reputed for handling
250MFlops.? Possibly it may handle a slimmed down version of the
sbitx with e.g. no gui.? The benefit of using the RasPi-zero
i.s.o. de RaspPi-4 is its power dissipation, less than 1W versus
more than 6W.?
Many thanks again for publishing this brilliant design which
enables us to be creative in SDR, at least at the surface of it.
73 Jean / ON4JRT
Op 29/07/2021 om 03:09 schreef Ashhar
Farhan:
Congratulations in the hack. I forgot to document
the second card. I add a virtual cable to enable wsjtx or fldigi
to run on raspberry pi. You will have to execute "sudo modprobe
snd-aloop" to set it up.?
I would first try running other sound apps (I
just run youtube videos on chromium) to see if the sound is
working?correctly.
Finally, I must warn you, the wm8731 i2c is very
finnicky. As a result, I moved the Si5351 to use a separate
pair of digital lines and I do the i2c protocol by manually
turning the bits on and off. You can see this used in i2c_bb.c
and si5351v2.c.
It would be lovely to see how the system works
as a build outside my own shack.?
I also had to move the si5351 off to the
mainboard to cure some spurs, but that is probably my slopping
wiring.
How are you powering the boards at 5 volts?
- f
Hi Ashhar,
Why did you switch from 27Mhz to 40Mhz may I ask ?
Thanks!
Best regards, Peter.
|
Hi Ashhar,
After solving some hardware issues on my little WM8731 board I
finally made it work, first with the alsa-utils then with sbitx
software itself, hence a little "eureka" for this successful proof
of concept.?
The WM8731 chip is indeed rather touchy (I had some bad
experiences in the past driving it from a STM32 chip) and since
its internal registers are write only, there is no way to check
their content.? Luckily, the series resistors in the I2S and I2C
lines proofed quite helpful.? Further, it took me a while to
understand that the Si5351 is controlled by its own soft I2C bus.?
Now the vfo and bfo generator module is also functional.? See
photo 6177, the toroids (2/1 rf transformers) in the clock lines
are an attempt to mach de outputs of the Si5351 to 50Ohm for the
mixers.?
Finally, I was able to "repurpose" an home build receiver front
end (from a previous project) out of my junk box to complete the
sbitx hardware, at least as a receiver.? This module (see photo
6178) contains a 30MHz LPF, a SBL-1 type mixer, a rf amplifier, a
45MHz 4 pole crystal BPF (Golledge 45G15B1), a 2nd rf amplifier
and a 2nd SBL-1 type mixer.? The output of the 2nd mixer is
provisionally send directly to the line input of the WM8731.? The
overall gain of this front end is about 10dB, too little for the
work (I will later add some amplification at 24kHz).? Also the
45G15B1 is not ideal for this application (the 15kHz bandwidth is
too small and stop bands do not fall fast enough), but it will do
for this proof of concept.?
See photo 6176 for a complete view of the set up, not very
practical using the RasPi-400 ?.?? See photo 6175, a screenshot
with the spectrum and waterfall when injecting a -60dBm RTTY
signal at 7053kHz, a really fantastic view !.?
The WM8731 annex Si5351 board is fully powered from the Raspi-400
(5V & 3.3V), the front end is powered separately from a 12V
source.? Again it it is just a proof of concept.?
I didn't modify the sbitx software (yet), safe for changing the
bfo frequency to 45024000. I intent to further hack the sbitx
software step by step wise so that it fits my purpose, i.e. having
a headless transceiver. I'll keep you posted.?
Obviously I do not intend to keep the SBL-1 mixers and 45G15B1
filter in a final design, I will rather wait patiently for
whatever hardware will be made available.? Though I may decide to
design my own hardware version of the sbitx. ??
I attempted to run this setup on a RasPi-Zero, it does not work.?
A cw signal comes out like that of a broken school bell, i.e. some
10ms of tone followed by 20ms of silence and so on.? Obviously the
RasPi-Zero is not powerful enough to run the full sbitx software,
a bit astonishing, the RasPi-zero being reputed for handling
250MFlops.? Possibly it may handle a slimmed down version of the
sbitx with e.g. no gui.? The benefit of using the RasPi-zero
i.s.o. de RaspPi-4 is its power dissipation, less than 1W versus
more than 6W.?
Many thanks again for publishing this brilliant design which
enables us to be creative in SDR, at least at the surface of it.
73 Jean / ON4JRT
Op 29/07/2021 om 03:09 schreef Ashhar
Farhan:
toggle quoted message
Show quoted text
Congratulations in the hack. I forgot to document
the second card. I add a virtual cable to enable wsjtx or fldigi
to run on raspberry pi. You will have to execute "sudo modprobe
snd-aloop" to set it up.?
I would first try running other sound apps (I
just run youtube videos on chromium) to see if the sound is
working?correctly.
Finally, I must warn you, the wm8731 i2c is very
finnicky. As a result, I moved the Si5351 to use a separate
pair of digital lines and I do the i2c protocol by manually
turning the bits on and off. You can see this used in i2c_bb.c
and si5351v2.c.
It would be lovely to see how the system works
as a build outside my own shack.?
I also had to move the si5351 off to the
mainboard to cure some spurs, but that is probably my slopping
wiring.
How are you powering the boards at 5 volts?
- f
Hi Ashhar,
Why did you switch from 27Mhz to 40Mhz may I ask ?
Thanks!
Best regards, Peter.
|
Re: uBitx V6 - Transmit logic in firmware
QRSS comes the closest of no side bands. It is pure 1 frequency switching on and off or changing up or down by 5Hz every 3-6 seconds.
Earl Cox? KB5UEW? Reply or E-mail me at:? kb5uew@...
On Thursday, July 29, 2021, 08:43:59 AM MDT, Bill Cromwell <wrcromwell@...> wrote:
Hi,
I frequently abuse my transmitters or transceivers as signal generators
(finals disabled). It is very handy to have the radio operate at
whatever frequency I need without some artificial restriction. I *know*
what frequencies I am licensed to use on the air and I managed to stay
in those limits for a very long time using many different transmitters.
None of our signals has? a zero bandwidth no matter how you think of
them. Yes, Virginia, that includes CW and WSPR. Setting the center of
your signal on 7.00000 MHz is sure to have the lower frequency part of
the signal outside the band. You might 'get away' with it if nobody
notices. Most of us have better things to do than play radios police but
there are some capable people who are paid to do that. Don't give them
something to 'find'. QSY to maybe 7.0001. For voice go to 7.004 (some
places can use voice anywhere in the bands (as far as I know). Keep the
margins for regulatory sub-band limits, too.
73,
Bill KU8H
bark less - wag more
On 7/29/21 12:53 AM, vu3gao@... wrote: > Hello OMs, > > While tinkering around with uBitx v6, I observed following: > > 1) VFO will take frequency from 5Hz to max 999.999.999. Expected to > have 3Mhz-30Mhz ring fence. > 2) Set transmits from as low as 500Khz to 35Mhz. Expected Tx > restriction within HAM bands. > 3) When dial is set to 7.000 Mhz, There is no output in Tx mode (Both > CW/ SSB). Tune little above or below there is output in TX mode. Seems > some filter switch logic issue. Expected to have Tx on band edge. > > Note: Firmware used during above observations: Reed N R1.51. uBitx V6 > users, please try to reproduce the above observation and revert. > Hoping code enhancement from Reed or Ashar towards excellent hardware. > > Thanks > Nitin William > VU3GAO >
|
I have been using the DROK ones from Amazon. ?They aren't cheap but then again I was looking for good, not cheap. ?My search was over after buying them.
?
Curt
WU3U
|
Re: uBitx V6 - Transmit logic in firmware
Hi,
I frequently abuse my transmitters or transceivers as signal generators (finals disabled). It is very handy to have the radio operate at whatever frequency I need without some artificial restriction. I *know* what frequencies I am licensed to use on the air and I managed to stay in those limits for a very long time using many different transmitters.
None of our signals has? a zero bandwidth no matter how you think of them. Yes, Virginia, that includes CW and WSPR. Setting the center of your signal on 7.00000 MHz is sure to have the lower frequency part of the signal outside the band. You might 'get away' with it if nobody notices. Most of us have better things to do than play radios police but there are some capable people who are paid to do that. Don't give them something to 'find'. QSY to maybe 7.0001. For voice go to 7.004 (some places can use voice anywhere in the bands (as far as I know). Keep the margins for regulatory sub-band limits, too.
73,
Bill KU8H
bark less - wag more
toggle quoted message
Show quoted text
On 7/29/21 12:53 AM, vu3gao@... wrote: Hello OMs,
While tinkering around with uBitx v6, I observed following:
1) VFO will take frequency from 5Hz to max 999.999.999. Expected to have 3Mhz-30Mhz ring fence.
2) Set transmits from as low as 500Khz to 35Mhz. Expected Tx restriction within HAM bands.
3) When dial is set to 7.000 Mhz, There is no output in Tx mode (Both CW/ SSB). Tune little above or below there is output in TX mode. Seems some filter switch logic issue. Expected to have Tx on band edge.
Note: Firmware used during above observations: Reed N R1.51. uBitx V6 users, please try to reproduce the above observation and revert. Hoping code enhancement from Reed or Ashar towards excellent hardware.
Thanks
Nitin William
VU3GAO
|
Re: uBitx V6 - Transmit logic in firmware
Dear Evan,
Thanks a Ton,
I did the change in the code.
In Reed's Firmware, The file is tuner.cpp
I change the > to >= and Uploaded the firmware, and it worked like a charm. ~7W out at 7000Khz.
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
void setTXFilters(unsigned long freq){
?
? if (freq > 21000000L){? // the default filter is with 35 MHz cut-off
??? digitalWrite(PIN_TX_LPF_A, 0);
??? digitalWrite(PIN_TX_LPF_B, 0);
??? digitalWrite(PIN_TX_LPF_C, 0);
? }
? else if (freq >= 14000000L){ //thrown the KT1 relay on, the 30 MHz LPF is bypassed and the 14-18 MHz LPF is allowd to go through
??? digitalWrite(PIN_TX_LPF_A, 1);
??? digitalWrite(PIN_TX_LPF_B, 0);
??? digitalWrite(PIN_TX_LPF_C, 0);
? }
? else if (freq >= 7000000L){
??? digitalWrite(PIN_TX_LPF_A, 0);
??? digitalWrite(PIN_TX_LPF_B, 1);
??? digitalWrite(PIN_TX_LPF_C, 0);
? }
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
73s,
VU3GAO
|
Re: uBitx V6 - Transmit logic in firmware
On Wed, Jul 28, 2021 at 11:53 PM, <vu3gao@...> wrote:
1) VFO will take frequency from 5Hz to max 999.999.999. Expected to have 3Mhz-30Mhz ring fence.
2) Set transmits from as low as 500Khz to 35Mhz. Expected Tx restriction within HAM bands.
3) When dial is set to 7.000 Mhz, There is no output in Tx mode (Both CW/ SSB). Tune little above or below there is output in TX mode. Seems some filter switch logic issue. Expected to have Tx on band edge.
Nitin, Your first two points above are the design of the radio.? There is not a limit on frequency for transmission.? That is up to the Ham running the rig. As to point 3, you are correct in that there is a small coding anomaly for 7.000000MHz that is due to the low pass filter selection.? That has been in all of the uBiTx that I have played with (v4 to v6).? It is in this section of the main .ino file starting at line 328:
Void setTXFilters_v5(unsigned long freq){
??
? if (freq > 21000000L){? // the default filter is with 35 MHz cut-off
? ? digitalWrite(TX_LPF_A, 0);
? ? digitalWrite(TX_LPF_B, 0);
? ? digitalWrite(TX_LPF_C, 0);
? }
? else if (freq >= 14000000L){ //thrown the KT1 relay on, the 30 MHz LPF is bypassed and the 14-18 MHz LPF is allowd to go through
? ? digitalWrite(TX_LPF_A, 1);
? ? digitalWrite(TX_LPF_B, 0);
? ? digitalWrite(TX_LPF_C, 0);
? }
? else if (freq > 7000000L){
? ? digitalWrite(TX_LPF_A, 0);
? ? digitalWrite(TX_LPF_B, 1);
? ? digitalWrite(TX_LPF_C, 0);? ??
? }
? else {
? ? digitalWrite(TX_LPF_A, 0);
? ? digitalWrite(TX_LPF_B, 0);
? ? digitalWrite(TX_LPF_C, 1);? ??
? }
}
It is transmitting, just heating up the 80meter low pass filter.
You could download the code from Ashhar Farhan's GitHub page, make the small change to add the >= compare and then download it into the uBiTx.? Ashhar Farhan has a video on how to do updates to the uBiTx v6 here:
The most recent firmware (or software) is here:
You can also search the messages on this board for program changes that limit transmit frequencies.? This was done by one Ham who wanted to take a uBiTx into a country that had requirements to prevent transmissions outside of their legal ham bands.? I remember reading it, just did not save the message number.
73
Evan
AC9TU
|
Re: uBitx V6 - Transmit logic in firmware
Just a matter of changing the bandpass filter settings in the firmware.
This was the first thing I did in the firmware to use the 6.something
MHz bands. I never really used the ubitx v6 as a ham transceiver, and it
works pretty well.
73s,
Rafael
toggle quoted message
Show quoted text
On 7/29/21 4:04 PM, vu3gao@... wrote: Dear Bob,
uBitx has come a long way in its maturity and perfection by accepting
areas of improvement and suggestions from all the builders across Globe.
On one hand having a general HF coverage receiver from 3Mhz to 30 Mhz
is good for an HF Hackable Rig, but it is silly to let it tune down to
5Hz sub audio frequency? and as high as quoted.
Secondly, 7.000 Mhz is where some QRP home brewer uses XTAL Controlled
sets ( Like Pixie) and having uBitx non txing will impact that
operation and if out of band transmission at the edges is a concern as
you said, then this should be applicable to all the bands :-) for
consistency and not just on 40M.
Lets be open to suggestions and improvement and take uBitx to next level.
Thanks
73s
|
Re: uBitx V6 - Transmit logic in firmware
Dear Bob,
uBitx has come a long way in its maturity and perfection by accepting areas of improvement and suggestions from all the builders across Globe.
On one hand having a general HF coverage receiver from 3Mhz to 30 Mhz is good for an HF Hackable Rig, but it is silly to let it tune down to 5Hz sub audio frequency? and as high as quoted.
Secondly, 7.000 Mhz is where some QRP home brewer uses XTAL Controlled sets ( Like Pixie) and having uBitx non txing will impact that operation and if out of band transmission at the edges is a concern as you said, then this should be applicable to all the bands :-) for consistency and not just on 40M.
Lets be open to suggestions and improvement and take uBitx to next level.
Thanks
73s
|
Re: uBitx V6 - Transmit logic in firmware
Regarding the VU3GAO Tinkering Report and??Notes to Reed & Ashar:
I do not have a V6 but will probably acquire one in the future.
5Hz to 999MHz? are great specs for a General Coverage receiver.? Please do not restrict reception to Ham Bands Only.
"Wideband Transmit" is a modification I have made to all my HF rigs.? Thanks for incorporating it in the V6.
The fact that the V6 will not transmit on 7.000MHz is not a problem for me.? I shouldn't be operating that close to the edge of the band.? Part of the transmission would most certainly be out of band.??
In short, If someone wants to restrict the operating parameters - Let them go for it - ON THEIR RADIO.? ?The uBITX was made for hacking.
73 Bob WB8BEL
From: vu3gao@... To: [email protected]Sent: Thursday, July 29, 2021 12:53:47 AM Subject: [BITX20] uBitx V6 - Transmit logic in firmware
Hello OMs,
While tinkering around with uBitx v6, I observed following:
1) VFO will take frequency from 5Hz to max 999.999.999. Expected to have 3Mhz-30Mhz ring fence. 2) Set transmits from as low as 500Khz to 35Mhz. Expected Tx restriction within HAM bands. 3) When dial is set to 7.000 Mhz, There is no output in Tx mode (Both CW/ SSB). Tune little above or below there is output in TX mode. Seems some filter switch logic issue. Expected to have Tx on band edge.
Note: Firmware used during above observations: Reed N R1.51. uBitx V6 users, please try to reproduce the above observation and revert. Hoping code enhancement from Reed or Ashar towards excellent hardware.
Thanks Nitin William VU3GAO
|
Thanks Ashhar, can you give me a suggested spec for the 40 Mhz crystal, I am going to put an order in on mouser in the next day or so and I will add the crystal to that order. I want to experiment a bit with a V4 I have sitting here to see if I can make this work, I already have the RPi 4 and the Mikroelektronika codec board.
Br Peter.
On Thu, 29 Jul 2021 at 02:13, Ashhar Farhan < farhanbox@...> wrote: Peter, With 40 Mhz IF I can get a full coverage of 0-30 mhz. Those unable to access 40 Mhz crysals (they are sold on mouser) can use 27 Mhz or even 25 MHz crystal with lesser coverage. For instance, with 20 MHz IF, you could potentially cover up to 14 MHz.
Hi Ashhar,
Why did you switch from 27Mhz to 40Mhz may I ask ?
Thanks!
Best regards, Peter.
|
uBitx V6 - Transmit logic in firmware
Hello OMs,
While tinkering around with uBitx v6, I observed following:
1) VFO will take frequency from 5Hz to max 999.999.999. Expected to have 3Mhz-30Mhz ring fence.
2) Set transmits from as low as 500Khz to 35Mhz. Expected Tx restriction within HAM bands.
3) When dial is set to 7.000 Mhz, There is no output in Tx mode (Both CW/ SSB). Tune little above or below there is output in TX mode. Seems some filter switch logic issue. Expected to have Tx on band edge.
Note: Firmware used during above observations: Reed N R1.51. uBitx V6 users, please try to reproduce the above observation and revert. Hoping code enhancement from Reed or Ashar towards excellent hardware.
Thanks
Nitin William
VU3GAO
|
Peter, With 40 Mhz IF I can get a full coverage of 0-30 mhz. Those unable to access 40 Mhz crysals (they are sold on mouser) can use 27 Mhz or even 25 MHz crystal with lesser coverage. For instance, with 20 MHz IF, you could potentially cover up to 14 MHz.
Hi Ashhar,
Why did you switch from 27Mhz to 40Mhz may I ask ?
Thanks!
Best regards, Peter.
|
Raj vu2zap
