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Re: Harmonics
I'm using the KD8CEC software that gives me 160m band coverage. ?It occurred to me that the 160m 3rd harmonic is less than the cutoff frequency for the 80m LPF in the uBITX! ?Duh!! ?I listened on the Eagle and sure enough it was as strong as the fundamental.?
So, I put 950pF ?(parallel 470 pf silvered mica caps) across one of the 900nF coils in that LPF and also 250 pF across another of the 900nF coils to reduce the 80m 3rd harmonic. ?Both bands now are noticeably weaker at 3X. ?power is down a watt or so on both bands. I would say that it probably isn't all the way fixed but I don't expect to be on either band much before an authoritative and do-able fix is found here. 73, Tom ?W1EAT |
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Re: Test for solving Spurs
#ubitx
Ian.
In the analog realm code code for the Raduino can only assure the oscillators (SI5351) are on the right frequency.? Not many levers we can apply there. Since we are analog for the RF the solutions are improve or add filters. I'm old and computers then were big and insanely expensive.? I'm glad I studied both! Computers got smaller, cheaper, and analog keeps going. Allison |
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Re: Compliance Summary - other radios
When I tested the ubitx it triggered exactly the same question.??
How are the other radios? The list includes: FT817, Argonaut 505, Triton m540, Eagle, KNQ7A, 20 Slopbucket, Kitsandparts 1W (cw only), and homebrew SSB monoband radios for 40,20,15,10.? For ancient to compare to I warmed up the HW101, Siltronix 1110C, and Tempo-one as an excuse to make sure they were ok and put a little time on them.?? The verdict was all passed with margin.? Some the margin was more than 20db.? For example my 1977 (manufacture date) Tentec Triton M430 the specs said not? less than -60dbc and it was better than spec 43 years later for everything.? The? modern OK mines about 12 years old) FT817 was spec or better.?? The poorest exceed spec was the 20M Small wonder labs White Mountain SSB as harmonics were-43dbc (at max power 3W) and the peak was? second harmonic with the rest better and carrier was -46dbc.? Not? bad for a 20 year old design and in use for the last 14 years. A recent build is the 20M slopbucket a KD1JV design.? Harmonics better? than -45 for second and better for higher. Carrier was -49db. For many simple radios the second harmonic is to be watched because? of the single ended output as its also harder to filter.? the WM20, Slopbucket, and KNQ7A and nearly all of mine fall into that category.? They pass. Also I can take any radio and push it to get truly horrific results.? Can't blame the radio for that. The tube rigs were interesting as once dialed up for the band it was good but over driven or tuned up wrong the second harmonic could climb out of accept range.? Considering the output of both of those were only single section pi networks for the outputs one would expect worse.? OF note was that spurs other than harmonics were not at all strong most being better than -55dbc.? This is attributed to much filtering (tuned preselection) in the lower level stages and the driver as well.? Considering the Siltronix 1011C? goes back to the days was 11M was a?ham band it was fine on 10M and fun. Filtering in the early stages does help and all do it that way with low pass filters for harmonic clean up due to the amplifiers used.? AS a result spurs were non existent or very low. One odd item as a response...? I have a siltronics 100W "cb" amp. With mods (bias circuit added) for class AB1 (1a standing current)?rather than class B (zero bias) the push pull amps is close to that of Motorola AN63 with MRF454s.? So I tested it without the nominal low pass filters used with it.? The drive was FT817 at 5W so the output was about 63W for 80 and 40 (works well higher but not tested for this) and harmonics were -38DBC for second harmonic and -33dbc for the third harmonic the rest were lower.? Of course it didn't pass but as to calling it filthy, not so?much.? ? With external filters normally used in place in the results were easily 15db (for second) and 23db (for the third)?which is better than required.? With harmonic suppression in the? mid -50s, 53dbc and 56dbc for both bands case closed. The filters, a set of filters built almost like those for the ubitx using the same values?with differences, bigger toroids, higher voltage caps and used a? dual section 4 position switch. Covers 80-60, 40, 20-17, 21-29mhz. I built it?last year so I never thought?to try it with ubitx but based on? this it would clean it up. Allison |
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Re: Compliance Summary
VBW is the postprocessing of the spectrum analyzer data before throwing it up on the screen,
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and determines how many hz wide a swath of acquired data will be included in that pixel of the display. Since the display is not blocky, I assume the center of the window is weighted heaviest, and as you approach VBW/2 away from the center the contribution of that acquired data approaches zero. But I'm left wondering if the display accurately shows the true peak power in dBm for each fundamental, harmonic, and spur. ? On Sat, Aug 11, 2018 at 09:11 AM, Jerry Gaffke wrote:
I'm not familiar with spectrum analyzers, still a little bit hazy about VBW. |
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UBitx Crystal filter capacitor Q
Larry N2AJX Wrote ¡°I swept the crystal filter and found its 3dB bandwith at only 1.2 kHz, less than half of what it should be. So I experimented a little and found that by changing the 5 capacitors from the crystals to ground from 100 pF each to 82 pF each, the bandwidth increased to 2.4 kHz¡±
(sorry for the size change with Pasting) On uBitx.net under Crystal Experimentation it says ¡±3) As suggested by Allison KB1GMX, 82pF is working just fine in the filter and achieves a bandwidth of around 2.2Khz. Capacitor value is bit touchy between 82 to 100pf. 4) The Q of capacitors used has a major impact on the filter response. Parallelling up two values to arrive at a desired overall capacitance value results in a better response.¡± |
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Re: Compliance Summary
Gordon Gibby
¿ªÔÆÌåÓýSuch wonderful data!? ?Warren, hoorah!
I'm stuck at a medical education seminar getting terabytes of knowledge being poured into my head on pacemakers and their application and interrogation.....but at slow moments?working on my simple "right-hand-side-of-filters relay system" printed
circuit board layout.? ?Using the DIPTRACE that you folks got me to learn how to use....? and at the same time one of our more-brilliant ARES volunteers has just figured out how to use PAT to do automated WINLINK from raspberries....which means he's
going to be providing yet another need for uBitx's....? ?It is good to see that on SSB they aren't THAT far out of compliance....but can be better!? ??
Below is a redrawn schematic showing the cuts to the traces that I think have to be made. (double red lines, and then the trace is erased).? ?
?Not quite sure what to do with the remaining, unnecessary? "between-relay" traces ---perhaps just GROUND them?
From: [email protected] <[email protected]> on behalf of Jerry Gaffke via Groups.Io <jgaffke@...>
Sent: Saturday, August 11, 2018 12:11 PM To: [email protected] Subject: Re: [BITX20] Compliance Summary ?
Here's where Warren parked his screenshots. ? ?? I'm looking at the screenshots for harmonics of the major bands of 80,40,20,15,10m Ignoring purple CW traces as there's an easy fix for that, just looking at the blue SSB traces. Ignoring the WARC bands, as I seldom use them and we have plenty on our plate already. In all cases, the transmitter is adjusted for peak at the transmitted frequency is at +33dBm, or 2 Watts, this adjustment might be made by varying the amplitude of a 1khz audio sine wave into the mike jack. The horizontal green cursor line is set 43 dB below that, or at -10dBm. Any harmonics or spurs that get above the green line are non-compliant. These displays are being generous, crank up the audio amplitude for more power than 2 Watts and the non-compliant emissions will likely be worse. 80m looks clean, I assume the peak at the far left edge is an artifact of the spectrum analyzer At 40m the 3'rd and 5'th harmonics are slightly non-compliant by 1 to 3dB, some might say that's not just too troubling. By 20m, the third harmonic non-compliant by about 5dB , out of complince,? more like 5dB At 15m, there' some cruft I don't understand well below 21mhz, otherwise compliant At 10m, same as 15m, looks compliant enough to me except the cruft at around 11.3mhz. So what's the low freq cruft I see on 15m?? Just artifacts of the test setup, or real emissions? Perhaps Allision has a point, and this will only be cleaned up by appropriate per-band BPF's at L1,2,3,4 of the uBitx. There is a short blip at??(45mhz - FOp) = 24mhz, but it is fully compliant. I'd guess it becomes non-compliant only when power is increased (by increasing the audio level into the mike) above 2W. ?? On 10m, the only non-compliant spur is a peak at about 11.3mhz, what's that? There is also a just barely compliant spur at 16mhz, which is our expected? (45mhz - FOp) spur.? I'm not familiar with spectrum analyzers, still a little bit hazy about VBW. But from what little I know the RBW and VBW selections seem good enough. The x axis is unfortunately not labeled in mhz.?? For those confused, consider the 10m screen shot here:?? At the bottom it says span=80mhz, center=50mhz, and there are 10 horizontal divisions shown in the display. So each division is 80mhz/10 = 8mhz, and the far left edge is 50mhz - 8mhz*5divisions = 10mhz The non-compliant peak is about 1/6'th of a division to the right of the far left edge, so at 10mhz + 8mhz/6 = 11.3mhz ? Jerry, KE7ER On Sat, Aug 11, 2018 at 07:00 AM, Warren Allgyer wrote: Farhan On Sat, Aug 11, 2018 at 06:31 AM, Ashhar Farhan wrote:
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Re: BITX40: Qui peut m¡¯aider ? Who can help me ?
? Merci ¨¤ tous les amis qui m'ont aid¨¦, mais difficile ¨¤ trouver. Heureusement un ami informaticien a trouv¨¦. Logiviel Arduino mal install¨¦ et bug dans le fichier. Murphy ¨¦tait au QRA. Mais tout fonctionne super, on va pouvoir avancer. Mais n'¨¦tant pas dou¨¦ en Anglais et en informatique c'est dur. 73¨¤ tous ³Ò¨¦²µ¨¦ ? ? ? > Message du 10/08/18 22:43 |
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Re: BITX40: Qui peut m¡¯aider ? Who can help me ?
Il faut aussi faire attention a un compte non administrateur sous Windows, cela g¨¦n¨¨re des messages d¡¯erreur sur l?ide arduino ressemblant ¨¤ des erreurs de compilation-> Faire la manip avec un compte administrateur.
you have to take care to a non-admin windows user that display some messages looking like compilation errors -> try with an windows administrator user remi f1mqj |
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Re: Compliance Summary - other radios
Tim, I am not absolutely sure but regarding the RM-Italy without lowpass filters I think they are not imported in the USA. If you download the manuals from their site they state the user must provide a low pass filter and they sell a 30mhz low pass filter for 10 meters. If you use it without a proper filter that is not allowed. They warn the buyer at least. There are other RM Italy models that have low pass filters for all the HF bands. They cost more of course and I think these models are exported to the US. Il 11/ago/2018 17:52, "Timothy Fidler" <engstr@...> ha scritto:
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Re: Test for solving Spurs
#ubitx
Allison Thank you for your feedback and test results.?I am not an RF expert like you. My major is not RF. I just wondered how Harmonics and Spurs can be easily tailored to the level that users want. Looking at the circuit and the source code, I figured out a couple of things to solve, but it seems like it was my mistake. I have one or two experiments left for this issue, but?I knew my experiment was wrong, so I do not think I need to go any further. Once this problem is solved by experts, I can expect to learn about it. Thank you again for testing. Ian KD8CEC 2018? 8? 12? (?) ?? 12:29, ajparent1/KB1GMX <kb1gmx@...>?? ??: On Sat, Aug 11, 2018 at 06:54 AM, Ian Lee wrote: |
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Re: Compliance Summary
Dennis Yancy,
There is what the radio can do and what the user did.? That case its what the user did and more than likely what the radio and amplifier can do is far better. The answer but people say I sound great does not measure excess bandwidth. Buckshot, sputter, and splash is not heard when you are tuned to the that station. Without detailing the problems with ubitx what I found caused me to review procedures and? compare radios.? Party to assure myself it was truly a problem with the radio and not some measurement or setup error.? If I did it wrong it would be easy to reproduce the problem. what I found was yes, unfortunately it is a problem with ubitx and I had to convince myself it was because I'd never seen that from a kit before.? There was a lot of work to find out why to follow. The list includes: FT817, Argonaut 505, Triton m540, Eagle, KNQ7A, 20 Slopbucket, Kitsand parts 1W (cw only), and homebrew SSB monoband radios for 40,20,15,10.? For laughs I warmed up the HW101 and Tempo-one as an excuse to make sure they were ok and put a little time on them. The verdict was all passed with margin.? Some the margin was more than 20db.? For example my 1977 (manufacture date) Tentec Triton M430 the specs said not less than -60dbc and it was better than spec 43 years later for everything.? The modern OK mines about 12 years old) FT817 was spec or better.?? The poorest exceed spec was the 20M Small wonder labs White Mountain SSB as harmonics were-43dbc (at max power 3W) and the peak was second harmonic with the rest better and carrier was -46dbc.? Not bad for a 20 year old design and in use for the last 14 years. A recent build is the 20M slopbucket a KD1JV design.? Harmonics better than -45 for second and better for higher. Carrier was -49db. For many simple radios the second harmonic is to be watched because of the single ended output as its also harder to filter.? the WM20, Slopbucket, and KNQ7A and nearly all of mine fall into that category.? They pass. Also I can take any radio and push it to get truly horrific results.? Can't blame the radio for that. That's a long summary, you asked for it. Allison |
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Re: Compliance Summary
Here's where Warren parked his screenshots. ? ??/g/BITX20/album?id=65861 I'm looking at the screenshots for harmonics of the major bands of 80,40,20,15,10m Ignoring purple CW traces as there's an easy fix for that, just looking at the blue SSB traces. Ignoring the WARC bands, as I seldom use them and we have plenty on our plate already. In all cases, the transmitter is adjusted for peak at the transmitted frequency is at +33dBm, or 2 Watts, this adjustment might be made by varying the amplitude of a 1khz audio sine wave into the mike jack. The horizontal green cursor line is set 43 dB below that, or at -10dBm. Any harmonics or spurs that get above the green line are non-compliant. These displays are being generous, crank up the audio amplitude for more power than 2 Watts and the non-compliant emissions will likely be worse. 80m looks clean, I assume the peak at the far left edge is an artifact of the spectrum analyzer At 40m the 3'rd and 5'th harmonics are slightly non-compliant by 1 to 3dB, some might say that's not just too troubling. By 20m, the third harmonic non-compliant by about 5dB , out of complince,? more like 5dB At 15m, there' some cruft I don't understand well below 21mhz, otherwise compliant At 10m, same as 15m, looks compliant enough to me except the cruft at around 11.3mhz. So what's the low freq cruft I see on 15m?? Just artifacts of the test setup, or real emissions? Perhaps Allision has a point, and this will only be cleaned up by appropriate per-band BPF's at L1,2,3,4 of the uBitx. There is a short blip at??(45mhz - FOp) = 24mhz, but it is fully compliant. I'd guess it becomes non-compliant only when power is increased (by increasing the audio level into the mike) above 2W. ?? On 10m, the only non-compliant spur is a peak at about 11.3mhz, what's that? There is also a just barely compliant spur at 16mhz, which is our expected? (45mhz - FOp) spur.? I'm not familiar with spectrum analyzers, still a little bit hazy about VBW. But from what little I know the RBW and VBW selections seem good enough. The x axis is unfortunately not labeled in mhz.?? For those confused, consider the 10m screen shot here:??/g/BITX20/photo/65861/0 At the bottom it says span=80mhz, center=50mhz, and there are 10 horizontal divisions shown in the display. So each division is 80mhz/10 = 8mhz, and the far left edge is 50mhz - 8mhz*5divisions = 10mhz The non-compliant peak is about 1/6'th of a division to the right of the far left edge, so at 10mhz + 8mhz/6 = 11.3mhz ? Jerry, KE7ER On Sat, Aug 11, 2018 at 07:00 AM, Warren Allgyer wrote: Farhan On Sat, Aug 11, 2018 at 06:31 AM, Ashhar Farhan wrote:
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Re: Compliance Summary - other radios
Hi,
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Apparently Dentron never got that radio into full production. I have only ever seen mine for 80 meters and another I exchanged info with another ham. His was for 20 meters. We had the same 5 MHz VFO and 9 MHz xtal filter. I will finish building a radio on it. 73, Bill KU8H On 08/11/2018 06:41 AM, Timothy Fidler wrote:
arghgh rew WBand SSB that might be one of those MPa'70 home built amps --
bark less - wag more |
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Re: A note about real vs. clone Arduino Nanos
I ve got some problem with the nano included in the raduino you could have the same with all blinking ? clones or genuine : it seems that one output was shorted to ground making great current consumption (about 200 mA) and atmega and 7805 heating ... this could also happent with nano tested with blink as soin as the shorted atmega pin is not the led one.
the best could be to use a true ? test program (and hardware) testing each pin as input with test contact, and in output with led. less time consuming : using nano on support, if any problem or doubt, check with another one (having one validated nano could permit to put some bad one to garbage, avoiding hours trying to debug another part) |
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Re: Harmonics
Timothy Fidler
ULN series relay driver chips switch to ground on positive input and are your friend if you want to have many transistor drivers replaced.
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http://www.ti.com/lit/ds/symlink/uln2003a.pdf directly compatible with (5V) TTL or 5 V Cmos. tuppence worth.? take ages to get through as there is a moderator in my case.. WHY ?? Timothy E. Fidler : Engineer BE Mech(1) Auckland , NDT specialist AINDT UT /RT3 , MT2 CB #2885,?
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Re: Compliance Summary - other radios
Timothy Fidler
arghgh rew WBand SSB that might be one of those MPa'70 home built? amps as in 20 dollars on ebay and no filter set? or perhaps an RM Italia amp with no filter (some yes,? some no plenty of hoods off photos on the internet to show the awful truth)? ?and run right at the stops in terms of drive. .. and the FCC does nix even though they are factory built amps and should have compliance tests before entry.
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? Timothy E. Fidler : Engineer BE Mech(1) Auckland , NDT specialist AINDT UT /RT3 , MT2?
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Re: Test for solving Spurs
#ubitx
¿ªÔÆÌåÓýAllison, I was wondering why the first IF could cause problems! But due to Your explanation I now understand the problem! It is not caused by the If filter itself but in TX mode by the amp beween the 45 MHz filter and the mixer, producing a second harmonic and even higher harmonics if driven too hard. So the effect must be output power related. As the transistors within this amp are limited in gain? due to their limited gain bandwidth product (my LTSPICE simulation showed a 3 dB gain reduction) higher harmonics must be much lower.? Using e.g. BFR106 insteead could worsen the spur problem. A simple remedy could either be a lowpass filter between the
output of the 45 MHz TX am and the mixer input or simply a 90 MHz
trap (bandstop filter)? Maybe a 45 MHz LC bandpass filter also
could help. ? Henning Weddig DK5LV Am 11.08.2018 um 17:29 schrieb
ajparent1/KB1GMX:
On Sat, Aug 11, 2018 at 06:54 AM, Ian Lee wrote: |
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