Hi Ripley, ? Thank you for the clarification!? My intent was to relate to Jerry that the bidirectional RF amps were still stock.? The amp immediately prior to the filter (that used to feed the mixer directly) has a trio of SMD 2N3904s marked Q20, Q21, and Q22 on the V3 schematic.? I didn't see that you'd replaced those with BFR106s yet, though might have missed plenty.? OM Farhan recommended changing R26 and R46 on the stock amps to help reduce distortion - something else for you to test.? hi hi?? /g/BITX20/message/61586? Is your signal in spec now except for 10 m SSB? ? ?Thanks again for? your work! ? ?Best, Andy
On Sun, Dec 9, 2018 at 02:10 PM, Ripley wrote:
Hi Andy,
?
A slight clarification, actually I replaced Q92, Q93, Q96, Q97 with 2N2222A and the emitter resistors along with Q90 and the change of resistors per Allison¡¯s recommendation First. Then checked for effect in evening out the power across the bands. Then I did the 45MHz crystal filter second. Once again checking the before and after results followed by the relay replacement of KT1-KT3. As with the other mods checking the before and after to see if it improved the performance.
?
I haven¡¯t been able to spend much time on the uBITX lately but the next thing that I want to try is replacing L5 and L7 with surface mount inductors per the experiment that Raj tried but I am also going to keep 45MHz crystal filter in circuit. I want to see if those two mods together will reduce those pesky spurs on 10 meter SSB further.
?
Ripley
?
Sent from for Windows 10
?
From: AndyH
Sent: Sunday, December 9, 2018 1:42 PM
To: [email protected]
Subject: Re: [BITX20] Ashhar Farhan #ubitx
?
A number of people are working to meet different thresholds of 'take care'-edness (two more times in print and it's a real word).? A few (probably in a nod to the phase noise wars) are pushing for a standard just shy of unobtanium.? Others are working to meet regulatory requirements.? Ripley, KD8UYQ, found that relays and a 45 MHz crystal/transformer/cap was quite effective.? That's on a board using the stock 3904s for Q20/Q21/Q22 and before Farhan's recent emitter current increase for Q21/Q22.
Thanks for pointing out Farhan's recent post about current production boards.? That's a curious statement and one that reverses two previous posts that make clear that the relays had been updated and that fixes are added to production on the fly.? I guess I'll "have" to order another one after the holidays and see what's different.
Interesting on needing to match the 45 MHz filters.? After enjoying the process of matching crystals for my in-progress scratch build, it might be interesting to check the 45 MHz filters I purchased from AliExpress and Mini-Kits.? If I recall, the point of the 2nd filter is to remove the "stuff not 45 MHz".? That might mean that a wider variant of the filter would be useful/usable there and might not need to be a narrow filter closely matched to Y1.? TIme to fire-up the Sweeperino, maybe.? Since matched pairs are available, though...
73, Andy, KG5RKP
On Wed, Dec 5, 2018 at 10:34 PM, Jerry Gaffke wrote:
I don't see a post yet that clearly spells out how to take care of the spurs.
This should include pointers to specific parts, show how they get mounted to the board,
include fixes for both the 45mhz-DialFreq and the 12mhz spurs.
And not be spread across dozens of different posts over the past couple months.
|
Hi Andy, ? A slight clarification, actually I replaced Q92, Q93, Q96, Q97 with 2N2222A and the emitter resistors along with Q90 and the change of resistors per Allison¡¯s recommendation First. Then checked for effect in evening out the power across the bands. Then I did the 45MHz crystal filter second. Once again checking the before and after results followed by the relay replacement of KT1-KT3. As with the other mods checking the before and after to see if it improved the performance. ? I haven¡¯t been able to spend much time on the uBITX lately but the next thing that I want to try is replacing L5 and L7 with surface mount inductors per the experiment that Raj tried but I am also going to keep 45MHz crystal filter in circuit. I want to see if those two mods together will reduce those pesky spurs on 10 meter SSB further. ? Ripley ? Sent from for Windows 10 ?
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From: AndyHSent: Sunday, December 9, 2018 1:42 PM To: [email protected]Subject: Re: [BITX20] Ashhar Farhan #ubitx ? A number of people are working to meet different thresholds of 'take care'-edness (two more times in print and it's a real word).? A few (probably in a nod to the phase noise wars) are pushing for a standard just shy of unobtanium.? Others are working to meet regulatory requirements.? Ripley, KD8UYQ, found that relays and a 45 MHz crystal/transformer/cap was quite effective.? That's on a board using the stock 3904s for Q20/Q21/Q22 and before Farhan's recent emitter current increase for Q21/Q22.
Thanks for pointing out Farhan's recent post about current production boards.? That's a curious statement and one that reverses two previous posts that make clear that the relays had been updated and that fixes are added to production on the fly.? I guess I'll "have" to order another one after the holidays and see what's different.
Interesting on needing to match the 45 MHz filters.? After enjoying the process of matching crystals for my in-progress scratch build, it might be interesting to check the 45 MHz filters I purchased from AliExpress and Mini-Kits.? If I recall, the point of the 2nd filter is to remove the "stuff not 45 MHz".? That might mean that a wider variant of the filter would be useful/usable there and might not need to be a narrow filter closely matched to Y1.? TIme to fire-up the Sweeperino, maybe.? Since matched pairs are available, though...
73, Andy, KG5RKP
On Wed, Dec 5, 2018 at 10:34 PM, Jerry Gaffke wrote: I don't see a post yet that clearly spells out how to take care of the spurs.
This should include pointers to specific parts, show how they get mounted to the board,
include fixes for both the 45mhz-DialFreq and the 12mhz spurs.
And not be spread across dozens of different posts over the past couple months.
|
Re: 2nd 45MHz filter - Power loss
TNX for the suggestions... Values are with RV1 adjusted to near maximum power.? Reach max before end of pot travel. FWIW, I have substituted the factory 45 MHz xtal filter with one of the two Tellurian units I have.? The other Tellurian is the second filter addition.? They said matched, but..?? Without major surgery, couldn't get a 15 pf across just the filter.? Tried across the whole xformer/filter assembly.? Not a significant change... Have most all the other spur / harmonic mods in place.? Trying to decide to leave it a very QRP TX, or put the 47 resistor back and get my 10+ watts back..... Woody ------------------------------ On 12/9/2018 18:33, ajparent1/KB1GMX wrote: Woody,
Yes but....? Did you try resetting RV1 to regain some of the power?
Also testing I did showed that for some filters the center frequency was
not nearly as offset as others as Mine and two other were closer to 45mhz than
stated and implemented in the Raduino firmware.? The result is adding a second
filter can have you down the band pass skirt and less power.
Try a small amount of C say 10 to 15pf across the filter input and output to "tune it".
Allison
_._,_._,_
------------------------------------------------------------------------
--
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A number of people are working to meet different thresholds of 'take care'-edness (two more times in print and it's a real word).? A few (probably in a nod to the phase noise wars) are pushing for a standard just shy of unobtanium.? Others are working to meet regulatory requirements.? Ripley, KD8UYQ, found that relays and a 45 MHz crystal/transformer/cap was quite effective.? That's on a board using the stock 3904s for Q20/Q21/Q22 and before Farhan's recent emitter current increase for Q21/Q22.
Thanks for pointing out Farhan's recent post about current production boards.? That's a curious statement and one that reverses two previous posts that make clear that the relays had been updated and that fixes are added to production on the fly.? I guess I'll "have" to order another one after the holidays and see what's different.
Interesting on needing to match the 45 MHz filters.? After enjoying the process of matching crystals for my in-progress scratch build, it might be interesting to check the 45 MHz filters I purchased from AliExpress and Mini-Kits.? If I recall, the point of the 2nd filter is to remove the "stuff not 45 MHz".? That might mean that a wider variant of the filter would be useful/usable there and might not need to be a narrow filter closely matched to Y1.? TIme to fire-up the Sweeperino, maybe.? Since matched pairs are available, though...
73, Andy, KG5RKP
toggle quoted message
Show quoted text
On Wed, Dec 5, 2018 at 10:34 PM, Jerry Gaffke wrote:
I don't see a post yet that clearly spells out how to take care of the spurs.
This should include pointers to specific parts, show how they get mounted to the board,
include fixes for both the 45mhz-DialFreq and the 12mhz spurs.
And not be spread across dozens of different posts over the past couple months.
|
Re: LSB signal looking more like AM
joshuaclough4@
Start with carrier balance pot and adjust with NO MODULATION for minimum power out.
There should be a noticeable null at about mid rotation.
Likely the carrier frequency setting is off as well and inside the filter band pass.??
Allison
|
Re: 2nd 45MHz filter - Power loss
Woody,
Yes but....? Did you try resetting RV1 to regain some of the power?
Also testing I did showed that for some filters the center frequency was?
not nearly as offset as others as Mine and two other were closer to 45mhz than
stated and implemented in the Raduino firmware.? The result is adding a second
filter can have you down the band pass skirt and less power.
Try a small amount of C say 10 to 15pf across the filter input and output to "tune it".
Allison
|
2nd 45MHz filter - Power loss
With stock R27, Power output close to
most reported.? Added 45MHz xtal filter, no transformer.? Power
dropped significantly.? Added cap and transformer.? Power up
slightly, not much.? Interesting, the power drop below 10 MHz...
For those who have done this mod, how does it compare to your
result regarding power output?
Here is my result:
Thanks, Woody? -? KZ4AK
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We believe the audio tones on some rigs come from harmonics of the 16mhz processor clock
beating with harmonics of the 12mhz BFO.? Most rigs don't have this, since the 12mhz
ceramic resonator is not very accurate, can be off by 100khz or so.?
That, and us old guys have lost the ability to hear anything much over 3khz.
Could drive the processor clock from the BFO, near 12mhz.
Should not create tones when it beats against itself.
The si5351 can glitchlessly transition that BFO by 3khz if we wish to switch from
low side to high side BFO (to switch between LSB and USB, keep clk1 on the high side.)
The 16mhz crystal resonator on the Nano is extremely small, will be tough for some to remove.
Perhaps leave it in place, overpower one end of it with a wire from the 12mhz BFO.
So this fix might be a matter of just adding one wire, and some new firmware on the Nano.
The ATMega328P has an internal processor clock generator that can be selected,
though it is even less stable than the ceramic resonator, and thus the birdies unpredictable.
Might be worth trying, as no hack is required except to the firmware.
Will be required to use the internal clock at startup until the si5351 is programmed
if the BFO is to be used as the processor clock.
Moving the crystal filter frequency to 11.052mhz should work, maybe that will show up on v5.
But matching 8 crystals for frequency, replacing the existing 12mhz crystals, evaluating
the filter passband given whatever crystal parameters you happen to have, and adjusting
caps and impedances for the desired bandwidth and filter ripple may be more than
most here want to take on.
If you have a good inspection microscope and no coffee, might be possible to swap
out the 16mhz ceramic resonator.? Any funny number for a frequency is likely to work
better than what we have.? We think we have trouble with 3*16 = 48mhz = 4*12.
If the processor were moved to 13mhz,? the first beat note I see is at 13*16= 208mhz = 16*13.
Those high harmonics will be very weak, won't get much better than that.
Remember to also avoid beats with clk1, at 45-12=33mhz and 45+12=57mhz.
Jerry, KE7ER
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On Sat, Dec 8, 2018 at 04:57 PM, <freefuel@...> wrote:
the Atmel AVR chip can be clocked up to 20MHz, with that said what frequency would be best if we were to replace the crystal on the Arduino board to shift that birdiey to another less offensive location.?
-Justin N2TOH
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Echoing the congrats, but ... Timothy and others: please note how Farhan spells the other part of his name (given or family? his locals evidently call him Ash). That part is pronounced as he writes it: two syllables, Ash and har. I'm not sure if there's an accent or dictionary-style diacritical mark or two in there - the Indian Sanskrit-based script might describe the pronunciation more fully. English gives a general idea but is sometimes half-hearted.
...just a mark of courtesy and respect ...
73 de ZL2DEX
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I¡¯ve seen some gear where the CPU clock frequency can be changed dynamically so any birdies from the CPU can by avoided. ?The AVR328 internal clock can be divided down from the crystal frequency under software control in powers of two from 1 to 256. ?Obviously if it¡¯s the crystal clock circuit itself that is causing birdies this won¡¯t help. ?The code would have to dynamically reset any timing based parameters (baud rate, timers, I2C clock and SPI clock) as well as synchronize the change (not make the change will data is gobbling transferred via any of the serial interfaces).
However there are settings in the clock oscillator which let you change from ¡°full swing¡± to ¡°low power¡±. ?If the fuses are currently set to use the full swing mode, the low power mode may mitigate the birdies.
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the Atmel AVR chip can be clocked up to 20MHz, with that said what frequency would be best if we were to replace the crystal on the Arduino board to shift that birdiey to another less offensive location.?
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it would be easier to just buy 11.052 mhz crystals and shift the IF out.? - f
the Atmel AVR chip can be clocked up to 20MHz, with that said what frequency would be best if we were to replace the crystal on the Arduino board to shift that birdiey to another less offensive location.?
-Justin N2TOH
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Read "Ashar"? Farhan - I can't edit the post and I am too lazy to repost it to correct the proper noun. TEF
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This URL may be of interest.? ? The software is a bit flaky but it is usable.??
https://in-the-sky.org/satmap_worldmap.php
ExseedSat after a quick perusal does not appear but? the data is updated from NORAD object data from time to time .. no doubt a? GIF of Ashan's face will? circumnavigate the globe on this site in the future.?
You can select? Amateur radio satellites under select satellites? - the default is mainly GPS satellites.? it is fascinating that as I watch Dec 9th Just after lunch there is only one GPS Sat over the continent? of Oz yet obviously GPS has not dropped out.? The other ones over the Indian ocean and the near Pacific? must be close enough to give the constellation of four? required for a GPS fix. The maps are of course live.
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AMSAT News Service Special Bulletin 341.01
From AMSAT HQ KENSINGTON, MD
DATE December 7, 2018
To All RADIO AMATEURS
BID: $ANS-341.01
On December 3rd, 2018, ExseedSat was launched on a Falcon 9 vehicle
from Vandenberg Air Force Base in California. Part of Spaceflight's
SSO-A: Smallsat Express launch, ExseedSat was built by a team of
Indian radio hams including Ashhar Farhan (VU2ESE), George Phillips
(VU2GT), Gurudutta Panda (VU3GDP), Sasi Bhusan (VU3ELR), and Nitin
Mutin (VU3TYG). Initial telemetry has been received around the world.
At the request of Exseed Space, AMSAT hereby designates ExseedSat as
VUsat-OSCAR 96 (VO-96). We congratulate the owners and operators of
VO-96, thank them for their contribution to the amateur satellite
community, and wish them continued success on this and future projects.
73,
Drew Glasbrenner, KO4MA
AMSAT VP Operations / OSCAR Number Administrator
Submitted by Russ? KG0BK
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Re: LSB signal looking more like AM
Thanks for the replies.
Will double check the sdr. The first time I used it (when it displayed the correct LSB signal) It didn't even have an antenna on it, I've since added an indoor (albeit non-hf) antenna, was hoping it would cut down on the sensitivity to an HF radio transmitting outside (the antenna at least, radio is in the same room).
Second to that, I'll try what someone PM'd, suggesting of using the Raduino V2 digital BFO sketch (evidently after doing the proper mods).
https://github.com/amunters/bitx40-raduino-v2
|
the Atmel AVR chip can be clocked up to 20MHz, with that said what frequency would be best if we were to replace the crystal on the Arduino board to shift that birdiey to another less offensive location.?
-Justin N2TOH
|
Replacing the BITX40 (and probably uBITX) relays with just a soldering iron
Hi all,
I had to replace one of my relays on the BITX40 recently and I made a video of the method I like to use. I'll be honest- some people aren't going to like my method. But it works for me!?
--
Ryan Flowers - W7RLF
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Not 'revising' but 'revisiting'.? soz Two other bits.? Earlier in this thread Farhan reports the benefit of changing R26 and R46 to 220 ¦¸ from 470 ¦¸.? This is for the stock amps, though - no idea if this is a necessary swap if the transistors are changed to BFR106. /g/BITX20/message/61586If you replace Q20/21/22, you want about 6 VDC at the collector of Q20. /g/BITX20/message/6141473, Andy
On Sat, Dec 8, 2018 at 04:23 AM, AndyH wrote:
No worries Nick - nothing wrong with circles.? hi hi? Revising the thread I see that you were part of it - sorry for the redundant link.
Here are Allison's suggestions for the two RF amps:
45mhz IF replace (Q20, Q21, Q22) with BFR106.? Change R23 to 18ohms.? Change R27 to 39 ohms.
12mhz IF amp change R43 to 18 ohma and put a .1uf in series with 680 ohms across R41.
/g/BITX20/message/51448
Cheers,
Andy
On Mon, Nov 12, 2018 at 08:36 PM, Nick VK4PP wrote:
Thanks Andy.
I have read that, but its all over the place a bit. Probably easy enough if you have a thorough working knowledge of electronics, But for a NOOB like me, I get some of what is said., but really a step by step
replace this with that. and maybe a commoners explanation of what is happening. Could be a good lesson on how these amps work.
My apologies if I seem to be going round in circles. but hey.
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No worries Nick - nothing wrong with circles.? hi hi? Revising the thread I see that you were part of it - sorry for the redundant link. Here are Allison's suggestions for the two RF amps:
45mhz IF replace (Q20, Q21, Q22) with BFR106.? Change R23 to 18ohms.? Change R27 to 39 ohms.
12mhz IF amp change R43 to 18 ohma and put a .1uf in series with 680 ohms across R41.
/g/BITX20/message/51448Cheers, Andy On Mon, Nov 12, 2018 at 08:36 PM, Nick VK4PP wrote:
Thanks Andy.
I have read that, but its all over the place a bit. Probably easy enough if you have a thorough working knowledge of electronics, But for a NOOB like me, I get some of what is said., but really a step by step
replace this with that. and maybe a commoners explanation of what is happening. Could be a good lesson on how these amps work.
My apologies if I seem to be going round in circles. but hey.
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Re: Homebrew from scratch
#ubitx
I would like to know whether? any other person is able to open these gerber files. If so can he /she help me with a 274X format files of the same.
Peter has already indicated that he would not respond for any message seeking help. Fine, and thanks.
regards sarma ?vu43zmv
On Sat, Dec 8, 2018 at 1:10 PM MVS Sarma via Groups.Io <mvssarma= [email protected]> wrote: Peter,
?Thanks for the new pcb artwork.
?For reasons, I have not been able to open your gerber files using a software "gerber Logix" or under sprint layout that has facility for inputting gerber files.
May I request you gerber files to 274X format please.
regards
sarma
vu3zmv
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Ripley
