Re: The issues of the TDA2822
From Farhan's post:? >? just about 100 out of 4000 boards have had this problem. >? and about less than 20 of them have reported the blow out."
So 100 boards got the WX part.
They all got turned on at HFSignals.in final test, very very few of the WX parts blew there.
It's only after they get out into the field and have a bit of operating time on them,
or perhaps see supply voltages of 14v or so, or have the speaker jack momentarily shorted,
that we see the 20 failures.? ?
HFSignals has a 2 month backlog on this product, and is scrambling to keep kits going out.
Lots of new electronics gear from established manufacturers will have these teething issues.?
Most of us have a spare LM386 or LM7805 from some older project we could patch in,
and if not they are easy enough to get.
What solution do you propose that's appropriate for a $109 kit
shipped from halfway around the world??
Jerry, KE7ER
On Sun, Mar 11, 2018 at 08:16 am, Christopher Miller wrote:
With all due respect sir, I eventually would like to purchase this kit as soon as I finish my disability claim in a month or so. This seems like a pretty serious issue. I am sure you didn't plan on parts failing but simply pointing out is only a percentage of your total production run isn't a solution.?
?
Overall from all the posts I read this kit is great. However I suspect you realized when shipping the boards with bad audio amps that it was an issue. If the original part was less than a dollar, you can easily raise the price by .50$ to 1$ us to cover the cost of putting a good part in.?
?
Thats just my .02$
?
kf4ftr
Chris?
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Re: RD16HHF1 power curve flattening...some
Glenn, Thanks for the wire size. I usually do not buy semiconductors from Ebay.? I have been burned too many times.? Just my preference.
Thanks again,
Marco? - KG5PRT?
On Mar 11, 2018 5:02 AM, "Glenn" < glennp@...> wrote: Plenty of MPSH10's on eBay.
I used 0.25mm wire? on the toroids. Just what i had basically.
glenn
vk3pe
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Re: ubitx mount question regarding lcd display and bezel
Mounting any LCD on a panel is a pain in the butt. Here¡¯s how I did it without drilling holes in the corners to hold the display.
After you have painstakingly cut and filed the panel to allow the display to fit, fasten four .250 aluminum standoffs, one on each corner, and tighten with the correct screw. Use the shortest screw you have.
check fitment and if necessary file away any panel material that might interfere with the display.
using a sharpie pen, mark the corners. Don¡¯t worry about being accurate, just a general location of each standoff will be enough.
remove the display.
use a bastard file and scratch around the area you just marked. The idea is to rough up the material.
Now, mix up a small batch of JB Weld.
Apply a generous amount to the bottom of each standoff, trying not to fill the hole up. (that¡¯s why it¡¯s best to use short screws so you don¡¯t epoxy the screw in!)
Mount the display and with clamps, clamp the display onto the panel. I use small Irwin clamps and wood paint stirring sticks.?
wait 24 hours.
Whoa! You¡¯ve mounted the display without trying to locate the mounting holes and without drilling holes!
Unless you go in there with a channel locks, you¡¯re not going to be able to break the bond between the epoxy and the aluminum.
Mike, WB8VGE
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Re: The issues of the TDA2822
Oh for crying out loud!
Could you folks leave this fellow alone?
He¡¯s manufacturing A quality piece of equipment for chicken feed, under difficult circumstances, when nobody else rose to do the job. He¡¯s run out of parts at least twice now when the worldwide demand for his product exceeded the worldwide supply of quality
components!
He didn¡¯t ask component manufactures to make him inferior parts, he simply purchase when you could find on the open market.
Once he ships it, it¡¯s beyond the pale to ask him to find a broken ones and replace them! All he can do his estimate the incidence, and try to find better component manufacturers.
If any of you want gear that is warranteed, built in first world circumstances, tested, then go pick yourself up an Icon 718 for about $650 US.
If you¡¯re not willing to learn a bit, work a bit, fix a bit, understand a bit, then please get off this man¡¯s back. It¡¯s unfair what you¡¯re doing.
Gordon L Gibby
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With all due respect sir, I eventually would like to purchase this kit as soon as I finish my disability claim in a month or so. This seems like a pretty serious issue. I am sure you didn't plan on parts failing but simply pointing out is only
a percentage of your total production run isn't a solution.?
Overall from all the posts I read this kit is great. However I suspect you realized when shipping the boards with bad audio amps that it was an issue. If the original part was less than a dollar, you can easily raise the price by .50$ to 1$
us to cover the cost of putting a good part in.?
Thats just my .02$
kf4ftr
Chris?
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Re: #uBITX Firmware KD8CEC - IF-Shift etc.
#ubitx
Yes Allard, I agree, It is a very effective and simple mod regardless of what you call it. I have been using it since your release and find it one of the best features of my Bitx. Willy
On Sat, Mar 10, 2018 at 7:09 PM, Allard PE1NWL <pe1nwl@...> wrote: Jerry,
I believe it works in a similar way as the PBT (or "clarifier") function
in the? Raduino v2 software for Bitx40.
It allows the user to slightly shift the BFO frequency from the frontpanel
(only during RX of course).
It's not IF shift in its true sense, but the behaviour is quite similar.
I have the impression that not many BitX40 builders actually installed
this mod, which has always surprised me as I personally find it a very
useful feature.
73 Allard PE1NWL
On Sun, March 11, 2018 00:52, Jerry Gaffke via Groups.Io wrote:
> OK, so IF-Shift is just a BFO offset (relative to the crystal filter
> passband)?
> that is for receive only, the transmit BFO offset generally stays put.
> Makes sense.
>
> I went off into the weeds there because Gerald's original query stated
> that
>>?In LSB I can adjust the received sound with the IF-Shift with a
>> very pleasing effect, but this does not work the same with USB.
>
> Sounded like there was something more going on.
> But could be just that the code didn't quite handle the USB case
> correctly.
>
> Yes, eventually I'll move on to try some of the newer software.
> But for now have my hands full with other projects.
>
> Jerry??
>
> On Sat, Mar 10, 2018 at 02:49 pm, Mike Woods wrote:
>
>>
>> Most commercial rigs have an IF Shift or Passband Tuning (PBT)
>> control.?
>> This control can help with removal of QRM on receive ( (
>> ) eliminating a strong carrier or another station on the
>> edge
>> of the passband by shifting the passband up or down by a few 100 Hz. It
>> can also compensate for a poorly adjusted frequency response on a signal
>> that is being received (too bassy or too trebly).?
>> ?
>> Ian¡¯s software implements just such a control.? It functions in a
>> similar
>> manner to the BFO calibration routine, in fact, but unlike the
>> calibration
>> function, it should only operate on RX. This was the bug - it didn¡¯t
>> turn
>> off on TX.? I checked on my uBITx and found the same problem here.
>> ?
>> If you haven¡¯t tried the KD8CEC firmware you should.? It has a number
>> of
>> other worthwhile software features!
>> ?
>>
>
|
Re: The issues of the TDA2822
With all due respect sir, I eventually would like to purchase this kit as soon as I finish my disability claim in a month or so. This seems like a pretty serious issue. I am sure you didn't plan on parts failing but simply pointing out is only a percentage of your total production run isn't a solution.?
Overall from all the posts I read this kit is great. However I suspect you realized when shipping the boards with bad audio amps that it was an issue. If the original part was less than a dollar, you can easily raise the price by .50$ to 1$ us to cover the cost of putting a good part in.?
Thats just my .02$
kf4ftr Chris?
|
Re: #uBITX Firmware KD8CEC - IF-Shift etc.
#ubitx
Allard, I don't think I agree with you. PBT and "clariier" are two different things. A "clarifer" or incremental tuning control is only useful for tuning an off-frequency signal. The BFO must be at the suppressed carrier frequency for proper detection of a SSB signal. If you deviate from that frequency then the detected audio becomes distorted, the old "donald duck" sound spoken of by the old-timers. One of my first ham-band receivers was an old RME-4350, 1950's vintage. It had a "BFO" control which was really useful on SSB because in a round-table not all transmitters could be set to the exact same frequency - resolution of 1kc was pretty good! The BFO could be used to tune everyone in properly, in essence it was what is today called an "receiver incremental tuning" control. Passband tuning (or IF Shift) does not impact the relationship of the BFO to the suppressed carrier at all. You could do the IF Shift by changing CLK1 in order to shift where the signal impacts the 12Mhz passband of the SSB filter but CLK0 would still have to maintain the same relationship to CLK2 in order to demodulate the signal properly. tim ab0wr On Sun, 11 Mar 2018 01:09:24 +0100 "Allard PE1NWL" <pe1nwl@...> wrote: Jerry,
I believe it works in a similar way as the PBT (or "clarifier")
function in the Raduino v2 software for Bitx40.
It allows the user to slightly shift the BFO frequency from the
frontpanel (only during RX of course).
It's not IF shift in its true sense, but the behaviour is quite
similar. I have the impression that not many BitX40 builders actually
installed this mod, which has always surprised me as I personally
find it a very useful feature.
73 Allard PE1NWL
On Sun, March 11, 2018 00:52, Jerry Gaffke via Groups.Io wrote:
OK, so IF-Shift is just a BFO offset (relative to the crystal filter
passband)??
that is for receive only, the transmit BFO offset generally stays
put. Makes sense.
I went off into the weeds there because Gerald's original query
stated that
??In LSB I can adjust the received sound with the IF-Shift with a
very pleasing effect, but this does not work the same with USB. Sounded like there was something more going on.
But could be just that the code didn't quite handle the USB case
correctly.
Yes, eventually I'll move on to try some of the newer software.
But for now have my hands full with other projects.
Jerry????
On Sat, Mar 10, 2018 at 02:49 pm, Mike Woods wrote:
Most commercial rigs have an IF Shift or Passband Tuning (PBT)
control.??
This control can help with removal of QRM on receive ( e.g.by (
) eliminating a strong carrier or another station on
the edge
of the passband by shifting the passband up or down by a few 100
Hz. It can also compensate for a poorly adjusted frequency
response on a signal that is being received (too bassy or too
trebly).? ??
Ian?€?s software implements just such a control.?? It functions in
a similar
manner to the BFO calibration routine, in fact, but unlike the
calibration
function, it should only operate on RX. This was the bug - it
didn?€?t turn
off on TX.?? I checked on my uBITx and found the same problem here.
??
If you haven?€?t tried the KD8CEC firmware you should.?? It has a
number of
other worthwhile software features!
??
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Re: Endian issues...final chapter
I agree with Jack.
There are many cases where ASCII protocols are just too cumbersome.?
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On Sun, Mar 11, 2018 at 07:58 am, Jack Purdum wrote:
Binary versus ASCII protocols simply hangs a second tool on your belt. You need to decide which best solves your design problem.
|
Hi all,
Thought I'd mention what I did to protect the LCD screen from getting scratched. I bought a screen protector for an iPad (or any other device would work) and cut it to fit. Just clean the surface well before applying.
Jeff
AD6RH
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Re: ubitx mount question regarding lcd display and bezel
Hi Tom, Not sure what bezel you have from the many that Digikey offers. My guess is that you are more interested in mounting the LCD without any visible fasteners. I know that some have mounted the display using only the pins into the main board for support and found that to be sufficient. That method does require careful positioning of the board and I see yours is already in place. Looking at your layout I think you could make some brackets which would be held in place by the tuning encoder,jacks, and volume control and hold the display from behind avoiding any thru holes in the front panel. Brackets could also be attached to the bottom panel to do the same thing. Of course you could get another bezel big enough to cover the thru front panel fasteners but it is always rewarding to figure out how to use what you already have. GL and looking forward to seeing your solution. 73 Willy
On Sun, Mar 11, 2018 at 9:45 AM, Bert N8NN <bertgarcia73@...> wrote: Tom -- Very nice tuning knob!? Can you provide the part number and source?
Thanks, Bert N8NN
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Re: #uBITX Firmware KD8CEC - IF-Shift etc.
#ubitx
Good catch.
My excuse for last night was it was too late.
Now it's too early.
The original (and incorrect) formulas from post 44182 was this:
? ? For USB, it's? ?VFO-(clk1-BFO)
? ? For LSB, it's? ?VFO+(clk1-BFO)?
The correct formulas are the duplicated ones that you spotted:
? ? ?For USB, it's? ?VFO-(clk1-BFO)
? ? ?For LSB, it's? ?VFO-(clk1+BFO)?
Thanks,
Jerry, KE7ER
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On Sun, Mar 11, 2018 at 07:57 am, Rod Self wrote:
Jerry,
?Huh? The formula correction at the bottom seems to be
no-change.? Is that what you meant?
Rod KM6SN
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Re: #uBITX Firmware KD8CEC - IF-Shift etc.
#ubitx
Yes, the tone of the CW signal should not change if IF-Shift (and/or BFO-Adjust,
whatever you want to call it) is implemented correctly by changing both?
the BFO and the VFO as mentioned in post 44182.
The original uBitx code implemented BFO-Adjust by only moving the BFO,
so the CW tone did change, and SSB speech becomes unnatural/unintelligible.
I have no idea what the various new versions of the code do these days.
Moving clk1 as somebody suggested a few posts back won't work,
we must adjust the 12mhz BFO (equal to the incoming suppressed carrier)
relative to the 12mhz filter passband.
?
Jerry, KE7ER
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On Sun, Mar 11, 2018 at 07:37 am, Tim Gorman wrote:
If you are listening to a CW signal then moving the IF Shift doesn't
change the tone of the CW signal at all. You are just moving the
passband. That can change the sound of a SSB signal because you are
removing some of the received audio along with the interfering signal.
Just like cutting the highs or lows with a treble/bass tone control.
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Re: Endian issues...final chapter
Totally agree when moving data between internet users. The downside is that binary 255 takes one byte but ASCII takes three bytes to push down a com link. If you are doing something computationally intensive, like moving FFT data to an SDR spectrum display, minimizing data transfer time can make a large performance difference. As Hans Summers (designer of the super-cool QCX transceiver from QRP Labs) pointed out, the endian issue must be handled even when writing to EEPROM on the same machine. You could store numeric data in EEPROM as ASCII, but then you need to pass through atoi() going into EEPROM and itoa() coming out. Clearly, Hans is storing his EEPROM data in binary.
CAT protocols like the one Ian Lee has worked on use an ASCII data transfer and it makes it so much easier to debug when something goes south. Even then, however, when commands can be as short as 10 bytes, someone reported a noticeable delay in response time. If you're only tool is a hammer, it should be no surprise that every problem looks like a nail. Binary versus ASCII protocols simply hangs a second tool on your belt. You need to decide which best solves your design problem.
Jack, W8TEE
From: Ashhar Farhan <farhanbox@...>
To: [email protected]
Sent: Sunday, March 11, 2018 12:49 AM
Subject: Re: [BITX20] Endian issues...final chapter
ietf solved this by insisting that internet protocos SHOULD be in plain text. it makes debuggera out our eyeballs and prevents testing of friendships.
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Re: #uBITX Firmware KD8CEC - IF-Shift etc.
#ubitx
Jerry,
?Huh? The formula correction at the bottom seems to be
no-change.? Is that what you meant?
Rod KM6SN
On 03/11/2018 07:43 AM, Jerry Gaffke
via Groups.Io wrote:
toggle quoted message
Show quoted text
It was getting late
when I pressed send, a couple minor errors crept in:
>? The 12mhz filter is passing audio between roughly 500 and
2500 hz in its upper sideband,
>? so the 12mhz filter is probably centered around 11996500 +
(500+2500)/2 = 1199800 hz.
>
>? With a clk1 for USB of 56995000 hz, the center of that upper
sideband in the 45mhz filter
>? would be 56995000-11998000 = 44997000 hz
>? With clk1 for LSB of 32995000 hz, the center of that lower
sideband in the 45mhz filter
>? would be 32995000+11998000 = 44993000 hz.
When I say "upper sideband in the 45mhz filter", I'm talking about
the upper sideband
of the original signal.? ?Should rewrite those last few lines with
a few more words:
? With a clk1 for USB of 56995000 hz, the center of that sideband
within the 45mhz filter
? (now below the carrier due to sideband inversion from the high
side VFO)
? would be 56995000-11998000 = 44997000 hz
? With clk1 for LSB of 32995000 hz, the center of that sideband
within the 45mhz filter
? (now above the carrier due to sideband inversion from the high
side VFO)
? would be 32995000+11998000 = 44993000 hz.
And I flipped the arithmetic at the wrong spot in these formulas:
>? The display shows the frequency of the suppressed carrier,
always easy enough to compute:
>? ? ? For USB, it's? ?VFO-(clk1-BFO)
>? ? ? For LSB, it's? ?VFO-(clk1+BFO)?
Those two formulas should read:
?
? ? ?For USB, it's? ?VFO-(clk1-BFO)
? ? ?For LSB, it's? ?VFO-(clk1+BFO)?
Jerry, KE7ER
On Sat, Mar 10, 2018 at 11:36 pm, Jerry Gaffke wrote:
I think Gerald's complaint about USB sounding
different than LSB winds up being due to
a USB signal going through the 45mhz filter a few khz away from
where an LSB signal does.?
Gerald was using Ian's code which I have not yet looked over.
I assume Ian borrowed numbers from the original uBitx code.
Here's my argument:
The original uBitx code has the BFO at
? ??#define INIT_USB_FREQ? ?(11996500l)
and uses these frequencies for clk1:
? ??#define SECOND_OSC_USB
(56995000l)
? ??#define SECOND_OSC_LSB
(32995000l)
The 12mhz filter is passing audio between roughly 500 and 2500
hz in its upper sideband,
so the 12mhz filter is probably centered around 11996500 +
(500+2500)/2 = 1199800 hz.
With a clk1 for USB of 56995000 hz, the center of that upper
sideband in the 45mhz filter
would be 56995000-11998000 = 44997000 hz
With clk1 for LSB of 32995000 hz, the center of that lower
sideband in the 45mhz filter
would be 32995000+11998000 = 44993000 hz.
That's a 4khz difference in where the center of the sideband of
interest got placed
within?the 45mhz crystal filter passband.?
Assuming the the 45mhz crystal filter is truly centered at
44.995mhz as the notes in the code suggest,
then I figure that values of 56993000 hz and 32997000 hz should
be optimal for clk1.
If the 45mhz crystal filter sweeps out to be somewhere else,
then add the difference to those two figures.
For example, if the center is found to be at 44.997mhz (so 2khz
higher) then the two figures for clk1
should be 56995000 hz and 32999000 hz.
Regarding Tim's writup:
> When you are talking about adjusting the BFO I assume
you are talking about adjusting CLK1.
No, we are talking about adjusting the BFO.
When adjusting the BFO, we should move the VFO to get us back to
the displayed frequency.
The display shows the frequency of the suppressed carrier,
always easy enough to compute:
? ? For USB, it's? ?VFO-(clk1-BFO)
? ? For LSB, it's? ?VFO+(clk1-BFO)?
where VFO is clk2, and BFO is clk0.
RIT allows a different VFO setting on receive than transmit.
This IF-Shift thing apparently allows a different BFO setting
(with attendant VFO correction)?on receive than transmit.
So IF-Shift will change what part of the sideband the 12mhz
filter will capture (and thus capture a different range of audio
frequencies)?
but does not change the frequency of the suppressed carrier that
we are tuned to.
CW is a bit different, but easy enough.
Jerry, KE7ER?
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Re: #uBITX Firmware KD8CEC - IF-Shift etc.
#ubitx
It was getting late when I pressed send, a couple minor errors crept in:
>? The 12mhz filter is passing audio between roughly 500 and 2500 hz in its upper sideband,
>? so the 12mhz filter is probably centered around 11996500 + (500+2500)/2 = 1199800 hz.
>
>? With a clk1 for USB of 56995000 hz, the center of that upper sideband in the 45mhz filter
>? would be 56995000-11998000 = 44997000 hz
>? With clk1 for LSB of 32995000 hz, the center of that lower sideband in the 45mhz filter
>? would be 32995000+11998000 = 44993000 hz.
When I say "upper sideband in the 45mhz filter", I'm talking about the upper sideband
of the original signal.? ?Should rewrite those last few lines with a few more words:
? With a clk1 for USB of 56995000 hz, the center of that sideband within the 45mhz filter
? (now below the carrier due to sideband inversion from the high side VFO)
? would be 56995000-11998000 = 44997000 hz
? With clk1 for LSB of 32995000 hz, the center of that sideband within the 45mhz filter
? (now above the carrier due to sideband inversion from the high side VFO)
? would be 32995000+11998000 = 44993000 hz.
And I flipped the arithmetic at the wrong spot in these formulas:
>? The display shows the frequency of the suppressed carrier, always easy enough to compute:
>? ? ? For USB, it's? ?VFO-(clk1-BFO)
>? ? ? For LSB, it's? ?VFO-(clk1+BFO)?
Those two formulas should read:
?
? ? ?For USB, it's? ?VFO-(clk1-BFO)
? ? ?For LSB, it's? ?VFO-(clk1+BFO)?
Jerry, KE7ER
toggle quoted message
Show quoted text
On Sat, Mar 10, 2018 at 11:36 pm, Jerry Gaffke wrote:
I think Gerald's complaint about USB sounding different than LSB winds up being due to
a USB signal going through the 45mhz filter a few khz away from where an LSB signal does.?
Gerald was using Ian's code which I have not yet looked over.
I assume Ian borrowed numbers from the original uBitx code.
Here's my argument:
The original uBitx code has the BFO at
? ??#define INIT_USB_FREQ? ?(11996500l)
and uses these frequencies for clk1:
? ??#define SECOND_OSC_USB (56995000l)
? ??#define SECOND_OSC_LSB (32995000l)
The 12mhz filter is passing audio between roughly 500 and 2500 hz in its upper sideband,
so the 12mhz filter is probably centered around 11996500 + (500+2500)/2 = 1199800 hz.
With a clk1 for USB of 56995000 hz, the center of that upper sideband in the 45mhz filter
would be 56995000-11998000 = 44997000 hz
With clk1 for LSB of 32995000 hz, the center of that lower sideband in the 45mhz filter
would be 32995000+11998000 = 44993000 hz.
That's a 4khz difference in where the center of the sideband of interest got placed
within?the 45mhz crystal filter passband.?
Assuming the the 45mhz crystal filter is truly centered at 44.995mhz as the notes in the code suggest,
then I figure that values of 56993000 hz and 32997000 hz should be optimal for clk1.
If the 45mhz crystal filter sweeps out to be somewhere else, then add the difference to those two figures.
For example, if the center is found to be at 44.997mhz (so 2khz higher) then the two figures for clk1
should be 56995000 hz and 32999000 hz.
Regarding Tim's writup:
> When you are talking about adjusting the BFO I assume you are talking about adjusting CLK1.
No, we are talking about adjusting the BFO.
When adjusting the BFO, we should move the VFO to get us back to the displayed frequency.
The display shows the frequency of the suppressed carrier, always easy enough to compute:
? ? For USB, it's? ?VFO-(clk1-BFO)
? ? For LSB, it's? ?VFO+(clk1-BFO)?
where VFO is clk2, and BFO is clk0.
RIT allows a different VFO setting on receive than transmit.
This IF-Shift thing apparently allows a different BFO setting (with attendant VFO correction)?on receive than transmit.
So IF-Shift will change what part of the sideband the 12mhz filter will capture (and thus capture a different range of audio frequencies)?
but does not change the frequency of the suppressed carrier that we are tuned to.
CW is a bit different, but easy enough.
Jerry, KE7ER?
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Re: #uBITX Firmware KD8CEC - IF-Shift etc.
#ubitx
Vince, If you are listening to a CW signal then moving the IF Shift doesn't change the tone of the CW signal at all. You are just moving the passband. That can change the sound of a SSB signal because you are removing some of the received audio along with the interfering signal. Just like cutting the highs or lows with a treble/bass tone control. tim ab0wr On Sat, 10 Mar 2018 21:07:17 -0500 "Vince Vielhaber" <vev@...> wrote: IF Shift is supposed to shift the signal thru the passband without
changing the frequency. So if you're listening to 3930 and there are
signals on 3928 (it happens daily) at the same time, you can use the
IF Shift to move the signals on 3928 out of the passband. If affects
the sound of the desired signal like a tone control but that's a side
effect of the action.
Vince.
On 03/10/2018 09:02 PM, Ronald Pfeiffer via Groups.Io wrote:
Yes I was confused a while back when Ian announced his IF shift.
The code looked just like our RIT. Our RIT displays the freq on
bottom line and the line above displays the plus/minus offset as
you move the encoder.
rOn
------------------------------------------------------------------------
*From:* Tim Gorman <tgorman2@...>
*To:* [email protected]
*Sent:* Saturday, March 10, 2018 8:24 PM
*Subject:* Re: [BITX20] #uBITX Firmware KD8CEC - IF-Shift etc.
I wonder if we need to define some terms here. Passband tuning and
IF Shift typically move the *filter*, not the carrier. The carrier
will remained tuned to the same frequency when adjusting this. For
instance, if you use IF Shift when listening to a CW signal the
tone of the CW signal should not change. You can move the filter
bandwidth up or down to eliminate an interfering carrier that is
close to the desired frequency.
What you are describing is more like an Incremental Tuning, e.g.
RIT or XIT. When you move the BFO you move the carrier frequency,
not the filter bandwidth.
Ideally the BFO would be set to replicate the suppressed carrier
frequency. The filter then determines what is heard.
The ubitx uses a 12Mhz crystal filter. I don't know its bandwidth or
what the actual absolute frequencies are. I haven't had a chance to
run a spectrum analyzer against mine. Let's assume it has a 2400hz
bandwidth and goes from 12,000,300hz to 12,002,700hz.
If you want to listen to a signal at 10Mhz then CLK2 should be
tuned to 55Mhz to generate the 45Mhz signal the first IF needs.
CLK1 should then be set to generate a 12Mhz signal, i.e. 33Mhz. For
an USB signal we should then see frequencies of 12Mhz to 12.003Mhz
(or whatever the transmitted bandwidth is, e.g. 0-3000hz). You will
then see frequencies of 12.0003Mhz to 12.0027Mhz out of the filter.
This is how an ideal receiver would work.
When you are talking about adjusting the BFO I assume you are
talking about adjusting CLK1. If you adjust CLK1 to move the actual
suppressed carrier frequency somewhere else in the filter bandwidth
then your frequency indication is going to be off. What should be a
10Mhz signal is going to look like something else.
This will cause an asymmetric USB and LSB response and frequency
indication.
If you want to change the BFO frequency on the fly then it should be
understood as being an incremental tuning so you can remember what
the base frequency should be.
Now each filter is probably going to have a different actual
physical, absolute bandpass. The BFO will have to be adjusted to
allow for this but the frequency indication needs to be adjusted as
well to match. It should be a fixed reference, not a variable one.
Your transmitted frequency has to be offset from the CW-tone if it
is to be zero beat with the received signal. If it isn't then
you'll never be zero beat. I'm assuming that the CWL and CWU
frequencies are indicating a frequency CW-tone away from the actual
transmitting frequency. That may be because your receive BFO
frequency isn't set to indicate actual carrier frequency.
I didn't mean for this to get so complicated but it isn't an easy
subject.
tim ab0wr
On Sun, 11 Mar 2018 01:08:55 +0100
"ge_clipboard" <clipboard@... <mailto:clipboard@...>>
wrote:
Hi All
Many thanks for all the response concerning the BFO adjustement and
about using the IF-shift. I have been playing around with the BFO
setting while monitoring myself on another transceiver but as I¡¯m
not getting there where I really would like to, I returned to the
factory settings. Leastening to the transmitted LSB and USB on
another transceiver was never symetric, maybe the steps to set the
bfo are not fine enough to do this or I am making something wrong.
Yes, the IF-shift is often a very helpfull feature within crowded
bands and as Mike pointed out, it is also nice to be able to adjust
the sound of a ssb signal on receive. So, if this could be
corrected in the software would be very fine.
Another point I¡¯ve noticed today while using CW, dx-cluster and CAT
to jump to a anounced station... When the CWL-, CWU-feature is
enabled, then the frequency is not spot on but offset by the amount
of the CW-Tone.
Nevertheless, this little rig is a joy to play with, especially
with all the added features by Ian¡®s software.
Vy 73, Gerald - HB9CEY
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Re: Board won¡¯t power up.
Ooops! the last couple of mails was men=ant to be private!
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At 11-03-18, you wrote: Send me a photo preferably by whatsapp, email will take more response time.
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Re: Board won¡¯t power up.
Send me a photo preferably by whatsapp, email will take more response time.
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At 11-03-18, you wrote: I have checked twice that the sacrificial diode is installed correctly.
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Re: Board won¡¯t power up.
Bruce,
Check the voltages with your -ve probe on the mother board. In case there is a ground fault in P1 or wire!
Raj
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At 11-03-18, you wrote: I think my microBitx main board may be defective. When powered up (without the raduino attached), according to the wiring instructions, it only draws 60-80 micro amps, rather than 90-110 mA the instructions specify. I have checked twice that the sacrificial diode is installed correctly.
Any ideas how to proceed?
Thanks,
Bruce W1BWA
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Re: Final implemented version of audio fix
My ubitx is still in production but I like your idea.
I wonder if the supply voltage could be limited with a resistor maybe a pot. At high power it would limit the voltage more also giving it a quasi AGC.?
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Willy
Raj vu2zap
_Dave_ AD0B