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Re: 4.2¡± Nextion Bezel?
¿ªÔÆÌåÓýChris: ? I greatly appreciated your offer to 3-D print. I just didn¡¯t want to put you through the trouble of having to order special materials you don¡¯t normally carry. I¡¯m sure I am not alone in wanting a bezel solution. So, if the group is aware that you have a solution, I think you would be of great service. Is there any place on the forum where people who offer various support-services such as this, can be easily found? ? Thanks, ? David A Posthuma, WD8PUO 1 (616) 283-7703 ? From: [email protected] <[email protected]> On Behalf Of Christopher Miller ? He is getting a laser cut acrylic version. I offered to print a few if he provided the material to produce the object . Instead they went with laser cut acrylic.? |
Re: uBitx Unfiltered
¿ªÔÆÌåÓýJerry: ? If it did come down to requiring a version-5 ubitx, I would hope there would be some discount to those of us who purchased version 3 or 4 with the understanding that it was a 80-10 meter transceiver, not just a legal 20-meter SSB transceiver with general coverage receive from 80-10 meters. I still hope a reasonable solution can be found to salvage the current generation of uBitx transceivers. ? David A Posthuma, WD8PUO 1 (616) 283-7703 ? From: [email protected] <[email protected]> On Behalf Of Jerry Gaffke via Groups.Io ? Of course, the uBitx should be a clean and solid 80-10m 10W rig.
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Re: uBitx Unfiltered
Jerry,
I was talking about an add-on filter board between T11 and K3 with all the existing onboard parts removed to populate the new plug-in filters or just disabled. Dual relay means a relay at each end of the LPFs/BPFs the filter is either connected to the RF bus or grounded, maximum number of series contacts is 2 and they are DPDT and bifurcated. Input RF and output RF is never combined in one relay, different LPFs/BPFs are never combined in one relay. 73 Kees K5BCQ |
Re: uBitx Unfiltered
Of course, the uBitx should be a clean and solid 80-10m 10W rig.
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Unfortunately, v3 and v4 don't quite do that, and would require extensive mods to achieve it. The high bands in particular are difficult. Perhaps v5 will come closer to the ideal. Jerry On Sat, Sep 1, 2018 at 09:59 AM, David Posthuma wrote:
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Re: KARMA and BITX
Way off topic.? The BITX20 group is not for politics. On Sat, Sep 1, 2018 at 10:59 AM Buddy Brannan <buddy@...> wrote:
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Re: KARMA and BITX
¿ªÔÆÌåÓýIsn¡¯t this like¡their third CEO in as many years (or perhaps two years)? Barry Shelley didn¡¯t last too long, did he? What¡¯s going on over there in Newington anyway?! I mean, apart from electronic magazines that are impossible to read with screen reading software.?
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Re: uBitx Unfiltered
¿ªÔÆÌåÓýKees & Team: ? I know my opinion may matter little since I am not an engineer but only a Ham for 44 years. I still have and use projects I built many decades ago. And when the sunspot cycle once again peaks, many of us who are now investing into perfecting our uBitx projects will regret if 15, 12, and 10 meters are not included in the final solution.? I want to encourage your team to think long-term and so strive for the most-excellent solution possible, that we all might be proud of our radios and enjoy them for many decades to come. ? ? David A Posthuma, WD8PUO 1 (616) 283-7703 ? From: [email protected] <[email protected]> On Behalf Of Jerry Gaffke via Groups.Io ? Kee's
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Re: uBitx Unfiltered
Kee's
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Are you talking filters at the output of the rig, for use with current v3 and v4 boards? That's likely the best bet for getting current rigs compliant. Me, I'm ok with dropping the high bands, maybe stick with just 80,40,20m. Killing spurs at 15m and 12m is difficult, and perhaps not worth the trouble at our latitudes given where we're at in the sunspot cycle. The current four transmit LPF's are sufficient for harmonic suppression if the board routing and relay scheme is clean. Not sure what a "basic dual relay" scheme is. I think the relay scheme of post 58293 is sufficient. Regarding where this rig should go on v5: Allison has said repeatedly that we need band specific band-pass filters where we currently have one 30mhz LPF at L1,2,3,4. She's built lots of this stuff and I respect her opinion. That's how pretty much all reg-compliant radios are built. But I am still very curious if we can tame the objectionable spurs with these changes: 1)? ?Use a PX1002 86.85mhz SAW filter instead of the 45mhz crystal filter (and appropriate transistors and transformers) 2)? ?Bring the local oscillators up to the required 7dBm.going into the mixers, keep mixer input signal levels 10dB below that 3)? ?Avoid having stuff from the power amp get into the IF amps. If that is sufficient to bring the spurs into compliance, we keep the radio almost as simple as it is now. The primary added complexity is additional gain required in the power amp to deal with the reduced signal from the mixers.? Somewhat related:? Clean up layout so the BFO does not jump across the 12mhz filter. Jerry,? KE7ER On Sat, Sep 1, 2018 at 09:20 AM, Kees T wrote:
Since most keep talking about the need for BPFs for certain bands, I "guess" the 80m-10m uBITX direction should be a board with 6 filter capability. How about a?basic?dual relay?switched filter board (3-1/4" x 3-7/8") with?up to?6 pluggable filters, all?manually?selected with a 6 position rotary switch --AND-- you can add a small mux board with 2N3904 relay drivers for the filters and a CD4028B mux to go from the 3 Raduino pins to the filters. Start with the existing 111,110,100,000 and add two others when you have the code modified. |
Re: CW PTT attack time to slow
#ubitx
Joop Stakenborg
¿ªÔÆÌåÓý
Okay! Sounds good, will have a look. I¡¯m afraid the stock firmware is unusable for serious CW transmissions. Thanks, Joop PG4I
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Re: CW PTT attack time to slow
#ubitx
Joop Stakenborg
Op 1 sep. 2018, om 03:41 heeft ajparent1/KB1GMX <kb1gmx@...> het volgende geschreven:Thanks Allison, I have now tried both the recent V4.3 from GitHub and KD8CEC¡¯s version. Ian¡¯s version works a bit better, attack time is improved but I am still missing part of the first dit to dah. The biggest issue is the software is a big loop and CW ke is checkedThanks for responding Regards Joop |
Re: uBitx Unfiltered
Makes more sense in this thread.............
Since most keep talking about the need for BPFs for certain bands, I "guess" the 80m-10m uBITX direction should be a board with 6 filter capability. How about a?basic?dual relay?switched filter board (3-1/4" x 3-7/8") with?up to?6 pluggable filters, all?manually?selected with a 6 position rotary switch --AND-- you can add a small mux board with 2N3904 relay drivers for the filters and a CD4028B mux to go from the 3 Raduino pins to the filters. Start with the existing 111,110,100,000 and add two others when you have the code modified. 73 Kees K5BCQ? |
Re: KARMA and BITX
Lawrence Macionski
Answer. The comment means- apparently someone is successful in the realm of electronics and ham radio. Another coincidental BITX success? It is simply newsworthy and I wish him well. Just like when Ashhar Farhan was inducted into CQ Amateur Radio Hall of Fame and noted here as well. Both men deserving.
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Re: Which xmit transistor is blown?
Sean,
Its been several days since you posted likely its eben seens and everyone is going "I dunno". ? ?Not enough description of whats going on or not going on. ? ?Not sure of the mods done. ? ?Are you sure the power supply is working ok. Everyone running FT8? without big fans seems to fry the amp and yet people run FT8 and likely at max power possible.? ?While technically it ignoring spurs and harmonics can there is insufficient cooling for sustained long transmit sessions.? HINT: cooling required. FYI hot is how hot?? You get a blister?? You don't what to hold your finger there long?? You feel warmth but its not painful? Many of the devices will heat to the very warm (about 140-150F).? That is not deadly to the devices.? It will make things like bad soldering stand out and maybe other marginal components fail.? Some have noted board level issues like open vias. Allison ? |
Re: UBITX V3 TX GAIN VARIATIONS
Jerry KE7ER,
>>I'll be buying that amp, once Hans starts selling it..?Then cut off the back half of my uBitx with a hacksaw. And you have half a radio....? That amp expect about 12-14dbm drive from the radio its attached to. That means for ubitx you still need about 32-34 db of gain hopefully not 3904s from the mixer output to the amp...? and still need a band pass filters for the bands above 17M and low pass filters, and there are issues with ground loops in the modulator and IF area. Its total gain is about 26-28DB.? To get from the mixer output though filters and result in 10W you need about 60DB of gain.? ? If you want even performance 3-30mhz you need to design that predriver section to be flat.? ? Which by the way is half the reason why the current amp has low power at 10M. As to the comment > Bag, cat, QSX amp.? The cats out of the bag, and its a QSX amp. Allison |
Re: VK4PP uBitx LPF BANK add-on Board
Timothy,
Have you ever looked at the board??? Fixing the driver moved the problem sage back to the predriver and first amp. Pulling bands at the time of its design was not considered as it was desired to have a 3-30mhz radio unbounded by "bands".? ?I agree a bounded transmitter is a must? but at that time it wasn't heard. Allison |
Re: VK4PP uBitx LPF BANK add-on Board
Timothy Fidler
If it is done cleanly it could look quite nice. Specifically small copper lugs can be soldered on the bottoms of the existing control relay pins to attach to braided core Cu wires which are then hot melt glued to the underside of the PCB for strength and brought out to a? green plastic header male plug?
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that is why I suggested the click in header carrying all voltage GND and the three signals to the PCB designer. If there is a known good solution to the existing issues that does not require a masters in EE to source and solder up then A Farhan has a prayer at moving? the remaining uBitx boards in Inventory.? Some people will chose to operate the thing unmodded and some with legal sensitivities will want a fix. After that inventory is moved, I suspect a full rework of the PCB will be out of the Eastern Horizon. My guess. Hopefully with AGC? and so on. Maybe with BS170 x 2? in the driver stage .? But what is set up as a standard as to what the relay control signals mean now will have to be carried through,? or all hope of? forward software compatibility will fly out the window. That is why a one of ten decoder to use those three lines makes a whole lot of sense even if it adds dollars to the price of the finished board. If you start pulling 15 and 17 metres off the table,? (combined filter) the multiband nature of the beast is compromised.? ? Timothy E. Fidler : Engineer BE Mech(1) Auckland , NDT specialist AINDT UT /RT3 , MT2?
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Re: VK4PP uBitx LPF BANK add-on Board
Yes, it would be a lot easier to simply disable the LPF's and use external filters.
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As per the final sentence here from long ago, keeps things very simple:?? ? ? /g/BITX20/message/30530 Given the uBitx board layout, trying to get more power on the upper bands will likely add to the spurs due to coupling from power amp to the IF stages. Board layout around the IRF510's is not that good for 30mhz, and the upper bands have more trouble with spurs.? I'd be happy with 80m,40m,20m, which the current uBitx can do a reasonable job of using external filters. But replacing the power amp would solve most of those issues.? No need for the hacksaw, just disable the uBitx power amp. Use coax for signals, I doubt the cabling will be much of an issue. Can experiment with band specific filters in that coax from exciter to power amp if necessary. Still need to address mixer levels, IF gain distribution, and a layout issue that allows the carrier to sneak around the 12mhz crystal filter. But the uBitx does give us a very simple analog SSB exciter/receiver to work with. Hacking up a uBitx to perform well with minimal cost and complexity might help give direction to future versions from hfsignals. Note that the G0UPL power amp will require nearly 20 dBm of power from the exciter.? Final mixer of the uBitx exciter should have about -3dBm max going in (10 dB below the 7dBm local oscillator), and loses 6dB.? So will want up to 30dB of gain between the uBitx exciter?and the G0UPL power amp, perhaps two MMIC's built ugly style on the back of the uBitx.? Not exactly trivial. Jerry On Sat, Sep 1, 2018 at 06:29 AM, MadRadioModder wrote:
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