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
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Re: VK4PP uBitx LPF BANK add-on Board
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? 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?
Telephone Whangarei?? 022? 691 8405
e: Engstr@...
----- Original Message -----
To: <[email protected]>
Cc:
Sent: Sat, 1 Sep 2018 08:29:31 -0500
Subject: Re: [BITX20] VK4PP uBitx LPF BANK add-on Board
My thinking is that this whole discussion of? butchering the uBITx board and cobbling in another board that, in itself, will have some sensitivities to things like cable runs and connections etc. will scare the unseasoned builder away from the uBITx completely.?
? I used what I thought was a better solution for some of the hams near me¡ by simply jumpering/cutting out the whole LPF network¡ so there is raw straight from the PA RF at the output.? I then used one of Hans¡¯ BPF modules outside the box with a minimal BNC to pins ¨C BPF ¨C pins to BNC that is about $5 worth of parts including the filter.? Now granted you must buy all of the filters for bands you want to operate¡ but it¡¯s the same with any LPF replacement? A complete board in an outboard box is even less scary to most.? Yes the rest of us will be at the uBITx endlessly with our hack saws, hot glue, and soldering irons¡ but that will only work for us hackish engineering students.
--
¡_. _._
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They are marginal at best... save your Money and get a better tuner...
--
72 and God bless
KD4EPG
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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. As per the final sentence here from long ago, keeps things very simple:?? ? ? /g/BITX20/message/30530Given 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:
My thinking is that this whole discussion of? butchering the uBITx board and cobbling in another board that, in itself, will have some sensitivities to things like cable runs and connections etc. will scare the unseasoned builder away from the uBITx completely.?
?
I used what I thought was a better solution for some of the hams near me¡ by simply jumpering/cutting out the whole LPF network¡ so there is raw straight from the PA RF at the output.? I then used one of Hans¡¯ BPF modules outside the box with a minimal BNC to pins ¨C BPF ¨C pins to BNC that is about $5 worth of parts including the filter.? Now granted you must buy all of the filters for bands you want to operate¡ but it¡¯s the same with any LPF replacement.? A complete board in an outboard box is even less scary to most.? Yes the rest of us will be at the uBITx endlessly with our hack saws, hot glue, and soldering irons¡ but that will only work for us hackish engineering students.
?
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Re: VK4PP uBitx LPF BANK add-on Board
My thinking is that this whole discussion of? butchering the uBITx board and cobbling in another board that, in itself, will have some sensitivities to things like cable runs and connections etc. will scare the unseasoned builder away from the uBITx completely.? ? I used what I thought was a better solution for some of the hams near me¡ by simply jumpering/cutting out the whole LPF network¡ so there is raw straight from the PA RF at the output.? I then used one of Hans¡¯ BPF modules outside the box with a minimal BNC to pins ¨C BPF ¨C pins to BNC that is about $5 worth of parts including the filter.? Now granted you must buy all of the filters for bands you want to operate¡ but it¡¯s the same with any LPF replacement.? A complete board in an outboard box is even less scary to most.? Yes the rest of us will be at the uBITx endlessly with our hack saws, hot glue, and soldering irons¡ but that will only work for us hackish engineering students. -- ¡_. _._
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Re: VK4PP uBitx LPF BANK add-on Board
The flaming obvious and yet trivial? has? just occurred. How are people going to mount the PCB as shown ?? Three hole posns at a minimum will be required for say 3.4mm holes.? Edge distances have to be allowed.? As long as it can be mounted on a bit of AL with a return on one side it can be bolted anywhere. As it stands it will have to be (hot melt glued ??) to something ..a bit like skyhooks required on some engineering projects in a way.? ?Even if people have to drill out prescribed rondels for the screw down on Rx of the board to keep the price down,? they still need to be nominated.?
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On Fri, Aug 31, 2018 at 10:41 AM, Lawrence Galea wrote:
Google?picatune ATU
I dust did. An interesting article with lots of good information. Tom, wb6b
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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.?
Ill get s copy of that object in case it comes up again and some one is ok with white or whatever color I happen to have.?
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I am sure I missed this topic, but my keyer worked fine until I upgraded the firmware to KD8CEC's V. 1.095 for use with my 4.3-inch Nextion?display. Since the upgrade, I can only use a straight?key. What did I miss??
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Re: CW PTT attack time to slow
#ubitx
On w0eb.com webpage is NANO software that implements interrupt driven CW generation.? Also
eliminates the voltage divider scheme.? Also eliminates the need to switch between straight key
and paddle as both are always active.
rOn
On August 31, 2018 at 9:41 PM ajparent1/KB1GMX <kb1gmx@...> wrote:
Joop,
IF you don't mind grinding code where are many possible fixes.
I would suggest looking at V4.3 as it is a bit cleaner and more current.
The biggest issue is the software is a big loop and CW ke is checked
a few times in the loop.? Speeding up the loop is one thing.? Or making
the input interrupt driven so when there is an event it gets the processors
attention.
Allison
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Re: UBITX V3 TX GAIN VARIATIONS
I'm convinced Hans did a good job.
Especially after seeing this in his post:
? "I am very grateful to Allison KB1GMX for her advice, encouragement, support and testing during the development of this Linear PA."
I'll be buying that amp, once Hans starts selling it..
Then cut off the back half of my uBitx with a hacksaw.
I had thought of the BS170 in regard to the uBitx in months past,
but figured it might be too lightweight when used as a linear.
And didn't fancy dealing with two more bias pots.
Will be interesting to see how Hans went about it
> Bag, cat, QSX amp.
I've heard of bag phones, though not bag HF linear amps.
And radio has been explained through the metaphor of a very long cat (or lack thereof)
But still seems a bit cryptic.
Jerry, KE7ER
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On Fri, Aug 31, 2018 at 06:20 PM, ajparent1/KB1GMX wrote:
Jerry,
If you have been reading I've mentioned I have several amps that actually do work...
Bag, cat, QSX amp.? I've been beating the crap out of one and its by far one of
the most solid designs to date.? Simply put, its that good.? For those that say?
it can't be done the answer is its done at last count everyone of the ones built
in SA YOTA 2018? its not a fluke.
Hans did some fine work.
Allison
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Re: UBITX V3 TX GAIN VARIATIONS
Jerry KE7ER,
The key to make it fly is layout to avoid ground loops and parasitics and
attention to cooling and that includes the BS170s.
There are pictures of his board. and for that fact the Softrock.? Many devices will
tolerate high peak power if a little attention is given to cooling.
The reason the amp works well is the BS170s aren't being flogged to drive the IRF510s.
and both with care have enough gain for the task.? There is ample headroom as 10W
needs about .5W from them and they can do 1W.
It did run at 10W swept frequency for over an hour.? I was interrupted and forgot it,
while I was doing something else.? At the 10W power level I've not yet found anything
that kills it.? Even when running into reactive loads.
Allison
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Re: CW PTT attack time to slow
#ubitx
Joop,
IF you don't mind grinding code where are many possible fixes.
I would suggest looking at V4.3 as it is a bit cleaner and more current.
The biggest issue is the software is a big loop and CW ke is checked
a few times in the loop.? Speeding up the loop is one thing.? Or making
the input interrupt driven so when there is an event it gets the processors
attention.
Allison
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Jim,
>>one other thing on the Elecraft T1 autotuner. ?I remember something that Wayne Burdick, N6KR (Elecraft founder and CEO) said about the T1. ?During initial testing of it, he messed up and accidentally hit it with 100 watts for a brief period (It's spec'd for 20W CW max) and it survived. ?Of course, this isn't recommended but it speaks well for Elecraft's product quality.??
Mine has survived accidents to much more than 20W.? And now the rest of the story... cockpit error... Running
QRP SSB QSO and we were getting fading on 40 so I hit the switch for the EBY amp (about 50W) and all was happy.?
Moved to 20M even remembered to change the band switch on the amp? and without thinking hit the T1 for
re-tune for 20M at about 50-55W,? it got weird and stopped with a bad match.? ?Reason the forward SWR detector
diode died.? The coils and caps can take it and tolerates a bit of abuse just don't tune at high power.
So yes I can recommend it and with no reservations.?
One of the best products I've built as a kit.
Allison
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Re: UBITX V3 TX GAIN VARIATIONS
On Friday, August 31, 2018, 3:11:21 PM PDT, ajparent1/KB1GMX <kb1gmx@...> wrote:
On Fri, Aug 31, 2018 at 12:41 PM, Jerry Gaffke wrote: Allison
_._,_._,_
Imma gonna put this here, tho it really does not apply to either the post I'm replying to or the "gain variations" as such If you want to know why the ubitx is generating all the "cruft" in the finals, look at the schematic especially L9 and L10. Both are wound on ferrite cores ..Both have DC current flowing through them ..According to the rev. 4 schematic they are supposed to be 60 uH ...I measured the ones I removed from my radio 23 uH ...just for fun, i monitored the impedance variation through them while passing DC current through them? O ma current, 23 uH ...5 ma current gave 15 uH ...10 ma current gave 11 uH ...since these inductors pass 100 mA (according to the setup procedure ...who knows what the inductance is under operating conditions ...Flowing DC through a ferrite biases the magnetic domains in the ferrite ...Maybe it goes back most likely not....ANY ferrite us susceptible to permeability change under the influence of a DC biasing current ...Its doubtful your "spice" analysis will account for this .. Make the finals look like the WA2EBY unit....Clean up the finals, then go chasing the remaining spurs (there are a few left I noticed)
Jim
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Re: UBITX V3 TX GAIN VARIATIONS
Jerry,
If you have been reading I've mentioned I have several amps that actually do work...
Bag, cat, QSX amp.? I've been beating the crap out of one and its by far one of
the most solid designs to date.? Simply put, its that good.? For those that say?
it can't be done the answer is its done at last count everyone of the ones built
in SA YOTA 2018? its not a fluke.
Hans did some fine work.
Allison
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Thanks, ? David A Posthuma, WD8PUO 1 (616) 283-7703 ?
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From: [email protected] < [email protected]> On Behalf Of Gary Hanson Sent: Friday, August 31, 2018 9:00 PM To: [email protected]Subject: [BITX20] 4.2¡± Nextion Bezel? ? David, Here is a two step process to get a black plastic bezel for your Nextion display. First, go to the ITEAD website and down load the 3d bezel zip file for the size of your display and unzip to your desktop. Go here:?
Next, go to??and?go through their order process that requires that you upload the file from step one above. ?You will need to indicate the color and the material you want to print with. I went with the cheapest and looks great. ?The 3dhub company has great customer service. Mine cost $9 including postage and took about 10 days. ?Hope this works for you. ?
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David,
Here is a two step process to get a black plastic bezel for your Nextion display.
First, go to the ITEAD website and down load the 3d bezel zip file for the size of your display and unzip to your desktop.
Go here:?
Next, go to??and?go through their order process that requires that you upload the file from step one above. ?You will need to indicate the color and the material you want to print with. I went with the cheapest and looks great. ?The 3dhub company has great customer service.
Mine cost $9 including postage and took about 10 days. ?Hope this works for you.
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Karma for not building an AM-FM radio design? (as per your group designator ). ??
Karma that is coming for making Irrelevant and meaningless posts on a technical forum ? and perhaps doing a bit of self promotion in the the process.?
Karma for? trying to design and build a multiband radio outside of Japan/PRC .??
What does the comment mean ??
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Re: UBITX V3 TX GAIN VARIATIONS
Hans let the cat out of the bag here:?? ? ? /g/QRPLabs/message/26092He's using a couple BS170's in push-pull to drive the IRF510's on the QSX. They look ideal. Ideal in that they approach $0.05 each in volume. I've got a bunch of BS170's here, bought for spares in my ATSprint and MTR rigs from KD1JV. He ran 3 in parallel, got a bulletproof 5 Watts out in class E for CW. Apparently, a push-pull pair of BS170's can give over a Watt in linear service as used in the Softrock Ensemble RXTX: ? ?? Note the curious circuit around Q4 and Q5 for setting the gate bias voltage. Q5, Q7 and Q8 should be matched for similar Vgs. Jerry, KE7ER
On Fri, Aug 31, 2018 at 03:06 PM, ajparent1/KB1GMX wrote:
MRM,
Actually I¡¯ve been doing a lot of experimentation on flattening/ linearizing the transmit chain.? The parts I¡¯ve fallen on are the NE46134¡¯s.? They have plenty of gain, Ft of 5 GHz, and with the proper inter stage transformer design¡ An almost flat (-0/+0.6 dB) frequency profile swept from 0.5-60 MHz is possible.? I suppose prototyped, it isn¡¯t much of a uBITx though.
Good part one of many that will work.? The right device and the right transformer,
The other third of the story is layout.??
Allison
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MadRadioModder
David Posthuma