Re: Never used V3 uBitx Board Available
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Re: Amplifier Talk- Communications Concepts
I know Helge and what you say is not true.? His RF designs are outstanding still today.? His work pioneered matching transformer designs for transistor devices, taking into account many parameters (saturation, capacitance, stray inductances, etc. over frequency).? His designs incorporated temperature compensated bias for thermal creep, and some later used RF chokes to offload current flux and pre-saturation from it in the RF transformers¡ something that few designs do even today. ? Now, if you mean that his amplifier boards didn¡¯t incorporate filtering to meet FCC regs (etc, name your country)¡ yes that is true.? This is because as you say his designs were demonstration designs, and it was left to the designer to add such filters¡ But that is true of almost everything you buy off eBay today except for complete amplifiers. ? MRM ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Razvan Fatu
Sent: Friday, September 13, 2019 3:52 AM
To: [email protected]
Subject: Re: [BITX20] Amplifier Talk- Communications Concepts ? The Motorola Helge Granberg designs are almost 30 years old now. Keep in mind they are only engineered to the level that demonstrates the functionality of a part and since then there have been important developments in materials and components. Once you understand that, designt he rest of the required circuitry and the right output filters, you might end up with a decent amp.
Alternatively, for about the same cost, less work and much more predictable results, you can find on eBay PA Units and Filter Units from old transceivers.
Cheers,
Razvan M0HZH -- ¡_. _._
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Re: Ubitx help In Cincinnati
Tony
Most important is to not mess up dc power connection.? do you have a dvm? You can and should verify each connection with the ohmmeter setting. Most important don't make a short circuit between positive and negative leads of your power source. Check everything before powering up. I see there is a new larger wiring diagram here. You can figure this out, don't be overconfident without checking things out.
After getting power right, much help available here. But do find folk nearby, check websites of local clubs.
Curt
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Re: SSB exciter with digital audio phasing
Hi
In my NEW SITE:
How to program the DSpic for digital audio phase shift 300Hz to 3kHz (in portuguese)
73 de py2ohh miguel
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Re: New wiring diagram version
OK thanks.
I've wired my ubitx yesterday evening and I've connected the +12V through a diode after the fuse.
The S1 switch (on the volume knob is cutting the +12V. For now the PA PWR is directly supplied.
For now it's OK my ubitx is turning on :-)
--
73's
Adrien F4IJA
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Re: Amplifier Talk- Communications Concepts
The Motorola Helge Granberg designs are almost 30 years old now. Keep in mind they are only engineered to the level that demonstrates the functionality of a part and since then there have been important developments in materials and components. Once you understand that, designt he rest of the required circuitry and the right output filters, you might end up with a decent amp.
Alternatively, for about the same cost, less work and much more predictable results, you can find on eBay PA Units and Filter Units from old transceivers.
Cheers,
Razvan M0HZH
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Re: 0dBm and -60dBm calibration
What I am saying here Hans is that 0dbm is no use to check an Antuino
unless
we have a 20db attenuator.
Calibrator will be useful for the Antuino between -20 and -80
Just like you are using a clock osc for signal reference, Antuino used
the internal
osc level for calibration. Its pretty accurate, worst case is 2db error
but mostly
1db. We can do better with AD8310 which is 0.5db with 20mv/dbm compared
to
AD8307 which is 1db error and 25mv/dbm. That mod will need sketch
correction.
Waiting to try that once I get back to town.
Initially drove me nuts so I call it Mentuino!
Raj
At 13/09/2019, you wrote:
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Hi Raj
> AFAIK the Antuino reads from -20dbm to -100dbm at the input. The IF
amp amps?
> the signal? by 30db making the -20dbm at input into +10dbm at the
AD8307. The
> sketch takes care? of the maths. Any higher level than -20 needs
external?
> attenuator (probably internal in? the next version?).
Question is - if the Antuino (or any other piece of test equipment) says
-34dBm (for example) on its screen... how do you know the accuracy of
that??
This calibration generator generates both 0dBm and -60dBm signals so the
latter would be suitable for Antuino testing.?
I do have a Dayton Antuino so could try it. But I am waiting on the
upgrade components pack...?
73 Hans G0UPL
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Re: 0dBm and -60dBm calibration
Hi Raj
> AFAIK the Antuino reads from -20dbm to -100dbm at the input. The IF amp amps?> the signal?by 30db making the -20dbm at input into +10dbm at the AD8307. The > sketch takes care?of the maths. Any higher level than -20 needs external? > attenuator (probably internal in?the next version?).
Question is - if the Antuino (or any other piece of test equipment) says -34dBm (for example) on its screen... how do you know the accuracy of that??
This calibration generator generates both 0dBm and -60dBm signals so the latter would be suitable for Antuino testing.?
I do have a Dayton Antuino so could try it. But I am waiting on the upgrade components pack...?
73 Hans G0UPL
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Re: Never used V3 uBitx Board Available
The whole kit (with display and raduino) or just the mainboard?
73,
Mark.
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Re: Amplifier Talk- Communications Concepts
Hi Jeff,
Well that one really is just a CB amp -- the biasing not linear and uses only a diode (a design for CW and FM use) and the output transformer design dated (leading to low efficiency).? The AN762-140 also low power in/140W out but is a much better design (with OK IMD specs) and $4 cheaper!?
73,
Mark.
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Re: 0dBm and -60dBm calibration
Hans,
AFAIK the Antuino reads from -20dbm to -100dbm at the input. The IF amp
amps the signal
by 30db making the -20dbm at input into +10dbm at the AD8307. The sketch
takes care
of the maths. Any higher level than -20 needs external attenuator
(probably internal in
the next version?).
Raj
At 12/09/2019, you wrote:
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Hi all
Possibly interesting for people with an Antuino who want to check the
calibration; or many other pieces of test equipment - I built an
interesting 7MHz signal generator with very accurate 0dBm and -60dBm
reference outputs yesterday. I made a YouTube video about it see?
73 Hans G0UPL
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I looking for someone in the Cincinnati area that can take a look at my Ubitx v5. ?I have it together, it powers up, but has no audio. ?I¡¯m a total noob at kit building & a relatively new to hf, passed my general not too long ago. ?I let the smoke out of the v v3 I put together. ?
Thanks, Tony
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Amplifier Talk- Communications Concepts
I see that there has been a little bit of talk about amplifiers for ubitx. ?Motorola published amplifier designs which used their transistors a few years ago and a company named Communications Concepts packaged many of them into kits with boards and parts- as much or as little as you want. ?These are not "kits" as in Elecraft or Heathkits or even ubitx. ?You really have to be able to go it alone with no one to hold your hand.
One that might fit the needs of the ubitx user is:
It takes 1-5 watts and makes as much as 140 watts out. ?They have the parts listed and you can buy everything except things like cases from them. ?The website is kind of cryptic I think to keep the "good buddies" from finding and building high power amps for their See Bees. ?But, poke around and you will find amps of varying power and type as well as the parts to build them. ?The Motorola documentation is there also.
eHam has some reviews of amplifiers built with information and parts from this site.
73
Jeff
--
Jeff, K7AIL ?CN87
raoul@...
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Re: Nearly non-existent output power, no mod
Use an RF probe or oscilloscope to trace the signal through the relays / filters.
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On Sep 12, 2019, at 4:36 PM, Ted via Groups.Io < k3rta@...> wrote:
Excellent line of investigation to follow.? Having replaced the finals (from Mouser) with predictably no change, I swapped out the Nano. New, known supplier, etc. No change.?
The relay power at K1 - K3 changes with band selection so unless a relay is stuck, the mystery?
just gets deeper.?? These are replacement Axicon relays, though anything can fail......
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Re: Nearly non-existent output power, no mod
Excellent line of investigation to follow.? Having replaced the finals (from Mouser) with predictably no change, I swapped out the Nano. New, known supplier, etc. No change.
The relay power at K1 - K3 changes with band selection so unless a relay is stuck, the mystery
just gets deeper.?? These are replacement Axicon relays, though anything can fail......
Ted
K3RTA
-Ted
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Re: Wired up Bitx40 and it doesn't work!
Jerry,
Thank you; I'll try those steps. 73, Mark/WU6R
On September 12, 2019 at 3:21 PM, "Jerry Gaffke via Groups.Io" <jgaffke@...> wrote: Mark,
>>? I double checked for polarity being backwards and it is wired correctly...
>? ? The bench power supply is outputting 12v and 2 amps, but at the bitx the voltage drops to 0.49v
So, you measure 12v across the power supply and at the same time you measure 0.49v
across the Bitx40?? Then somewhere there is 11.51v drop across a bad connection,
you should be able to find that with a voltmeter.
If that power supply is sending out 2 Amps, that means 2 amps * 11.51 volts = 23 Watts of power
getting dissipated across that bad connection, and it is smoking hot.
I doubt that is the case.
My guess is that you see 12v at the power supply until you turn on the Bitx40,
at which point the power supply goes into current limiting and drops to around 0.49v.
Try unplugging PA-PWR (which gives 12v to the IRF510) and unplugging the Raduino.
Does it still drop to 0.49v?
Then something is dissipating 2 amps * 0.49v = 1 Watt, and if you feel around
the board with your fingers you will probably find something that's getting warm.
And that will be where the fault is.
If that doesn't find it, then disconnect stuff (with power off) until the voltage at the Bitx40 pops up to?
12v where it should be when you turn the power supply back on.??
Verify that the TX power rail has 0.0 volts on it (relay K1 is not stuck on).
If so, then the fault is in either on the 12v rail or the RX rail, as labeled in the schematic.
I assume you still see something like 0.49v on the 12v and RX rails when power is on,
perhaps somewhat less due to voltage loss with 2 Amps flowing through the power supply
wires and board traces.
You may be able to find the fault by measuring all points in the schematic labeled as either RX or +12v,
the point with the lowest voltage on it (some small fraction of a volt) should be near the fault.
If that doesn't do it, you may have to start removing parts or cutting traces to all places?
labeled RX and +12v in the schematic.? You know you are very close when you cut a portion
of the circuit out and the power supply now goes up to 12v when turned on.
Good luck!
Jerry, KE7ER
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Re: Wired up Bitx40 and it doesn't work!
Mark,
>>? I double checked for polarity being backwards and it is wired correctly...
>? ? The bench power supply is outputting 12v and 2 amps, but at the bitx the voltage drops to 0.49v
So, you measure 12v across the power supply and at the same time you measure 0.49v
across the Bitx40?? Then somewhere there is 11.51v drop across a bad connection,
you should be able to find that with a voltmeter.
If that power supply is sending out 2 Amps, that means 2 amps * 11.51 volts = 23 Watts of power
getting dissipated across that bad connection, and it is smoking hot.
I doubt that is the case.
My guess is that you see 12v at the power supply until you turn on the Bitx40,
at which point the power supply goes into current limiting and drops to around 0.49v.
Try unplugging PA-PWR (which gives 12v to the IRF510) and unplugging the Raduino.
Does it still drop to 0.49v?
Then something is dissipating 2 amps * 0.49v = 1 Watt, and if you feel around
the board with your fingers you will probably find something that's getting warm.
And that will be where the fault is.
If that doesn't find it, then disconnect stuff (with power off) until the voltage at the Bitx40 pops up to?
12v where it should be when you turn the power supply back on.??
Verify that the TX power rail has 0.0 volts on it (relay K1 is not stuck on).
If so, then the fault is in either on the 12v rail or the RX rail, as labeled in the schematic.
I assume you still see something like 0.49v on the 12v and RX rails when power is on,
perhaps somewhat less due to voltage loss with 2 Amps flowing through the power supply
wires and board traces.
You may be able to find the fault by measuring all points in the schematic labeled as either RX or +12v,
the point with the lowest voltage on it (some small fraction of a volt) should be near the fault.
If that doesn't do it, you may have to start removing parts or cutting traces to all places?
labeled RX and +12v in the schematic.? You know you are very close when you cut a portion
of the circuit out and the power supply now goes up to 12v when turned on.
Good luck!
Jerry, KE7ER
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Re: Is there a Raduino replacement with supply voltage, FWD & REF readings ?
Thanks I'm using the resistors that came with the kit. At 81 I think I'm Loosing It. 73 Jim
----- Original Message ----- From: Michael Hagen via Groups.Io <motdog@...> To: [email protected]Sent: Thu, 12 Sep 2019 12:03:27 -0400 (EDT) Subject: Re: [BITX20] Is there a Raduino replacement with supply voltage, FWD & REF readings ?
Relay K1 has 12v
connected to Tx or Rx.?? You can get it off the schematic
anywhere Tx or Rx is connected.
Use a current limiting
resistor for Led indicators. Mike, WA6ISP
On 9/12/2019 8:46 AM, James Baird
wrote:
Can someone Please tell me where the TX-RX on the LED hooks
up on the uBITX Board? Thanks?? Jim Baird W5OMM HOT IN TEXAS
----- Original Message -----
From: Razvan Fatu <razvanfatu@...>
To: [email protected]
Sent: Thu, 12 Sep 2019 06:45:53 -0400 (EDT)
Subject: Re: [BITX20] Is there a Raduino replacement with supply voltage, FWD & REF readings ?
Thank you for the replies.
I've looked at the CEC and JackAl expansions, they are nice
but add unnecessary complexity for this specific purpose and
neither seems to have all these minor but specific features I'm
looking for. Looking for a "less is more" approach if possible.
@ John, thank you for all the information, that's very close
to what I'm looking for. I like the way you use the limited
display area, I think this is quite close to what I need. I need
to spend a bit of time on it.
Razvan M0HZH
--
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID "MotDog@..."Mike@...
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Never used V3 uBitx Board Available
I have a never used - never powered uBitx version 3 board available for sale for $50 plus shipping - US only. If you ever wanted a spare, now is the time. First come, first serve. I accept payment by PayPal. Respond direct to me via the links below the message.
73,
W7DAO
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Re: Compliance Summary - other radios
Hi Allison, i did get the prebuilt band pass filter from ebay.? Wondering if you have any suggestions to mod the KL-203 as well as how to mod it to be more sensistive to lower power e.g. from softrock <1w; I am able to trigger AM but not via SSB.
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MadRadioModder
Raj vu2zap
Ted