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Re: New Member intro

[email protected]
 

On 2021-04-09 14:14, Curt via groups.io wrote:
Jerry
Hang in there, and perhaps this way more of it goes to hard working
people who kit these. It is quite an interesting rig, but not one I
would necessarily recommend for 600 watt operation. Most 600 watt amps
need more than 10 watts input, but its possible. Ubitx sometimes have
higher spurs than other rigs. Most of us have one for fun.
Lots of digital modes now. Lots of activity. If you can land a 100
watt rig its a great start.
*** It's not about needing a rig. It's about having fun. Stuck at home, bored
because of COVID. I have a TS590. And an Icom IC706MKII. And a collection of
SBE 34 transceivers - some working, some less so. And some ARC-5's in storage.

I did order the linear kit. It
takes 10W drive for 600 out. Might regret that. Somebody built a new house about
70 feet away from my antenna. Big house, with every gadget known to man.

In the mean time, I think it would be really nice to have a little amp that just sits in the corner and quietly - no fuss no muss - makes 600W. I do have a couple of big tube amps - a 30L1 and an Alpha 78 - but they're just too big and noisy to use in the
bedroom. They're more like "garage" equipment.

Don't give up on cw. We have a blast in soccer.
*** I do like CW. Just not that good at it :). Back in the 80's I used a CW training program on my TRS-80, and got up to 22WPM with code groups. The Extra test was just
20WPM, and plain text.

- Jerry
Re: UBITX V6 My Way!! - ATU integration #nextion #ubitxv6

 

My PICKit 3 got here a day early so I proceeded to rip into my UBITX and tweak the tuner programming.? The video??nails the process and I had no problems modifying the max power, n-turns, and min power.? Although I had rewound my binocular transformer with 5 turns after changing this value in the PIC the wattage read much lower than it should.? I changed the n-turns value to 6 and now the displayed wattage closely matches that of my MFJ Mobile Tuner.? It's nice to be able to hit the key and have it tune!

73,

Justin B.
KI5GKD
Re: uSDX

 

Bob - I have ordered the "through-hole" version since I am a lot more comfortable with that type of construction.? I will read more when I get time.

Pierre - That's not a bad price especially with all the "stuff" that comes with it but I'm not really sold on the color!
Re: New Member intro

 

Jerry

Hang in there, and perhaps this way more of it goes to hard working people who kit these. It is quite an interesting rig, but not one I would necessarily recommend for 600 watt operation. Most 600 watt amps need more than 10 watts input, but its possible. Ubitx sometimes have higher spurs than other rigs. Most of us have one for fun.?

Lots of digital modes now. Lots of activity. If you can land a 100 watt rig its a great start.?

Don't give up on cw. We have a blast in soccer.

Curt wb8yyy
Re: New Member intro

[email protected]
 

On 2021-04-09 11:59, John Cunliffe W7ZQ wrote:
If you had ordered from Giga Parts in the US for the same price you
could have had it tomorrow :=P
*** Yeah, rub it in :).

- KF6VB

John
Links:
------
[1] /g/BITX20/message/87494
[2] /mt/81976374/243852
[3] /g/BITX20/post
[4] /g/BITX20/editsub/243852
[5] /g/BITX20/leave/10189903/243852/952924773/xyzzy
Re: New Member intro

John Cunliffe W7ZQ
 

If you had ordered from Giga Parts in the US for the same price you could have had it tomorrow :=P

John
Re: New Member intro

 

Jerry,

Name here is Jerry, KE7ER.
A ham since the early 1970's.
Mostly interested in the technical puzzles, typical SSB contacts are not very motivating for me.

Not sure what current shipping times are.
Mumbai is in the thick of a Covid19 outbreak, that may or may not have significant impact.
In the past, many have reported receiving via DHL in around a week.

The uBitx is a hackers delight, a brief look at this forum will tell you that.
It is primarily an SSB rig, CW is an afterthought.? (Consider the QCX if you want a good cheap CW rig.)
There is no QSK for CW, and the first dit of each transmission might get clipped off depending on the firmware used.
The CW keying envelope on the stock rig is rectangular, there will be key clicks which would be problematic when
driving a 600W linear.
In SSB mode, IMD and various spurs can pop up if you give it too much mike gain,
I'd want tools to monitor signal quality if boosting to 600 Watts.

Where the uBitx shines is as a learning tool.?
Many in the forum have modded it, broke it, and then fixed it.
And came out the other side quite a bit smarter.
I'd be afraid to take the covers off a $1k+ HF transceiver, on the uBitx they come already off.

The Ebay linear amps are often, well, ebayish.? Buyer beware.
Often come with no instructions, and often must be modified extensively to work at all.
Power out may be a fraction of what is claimed.
A high power linear will likely require more power going in than the uBitx has to offer.
Some in the forum have succeeded with ebay amps, you might ask here for advice.
Some have not.

I'd recommend playing with the uBitx barefoot first.
Sounds like you have a great antenna, should make plenty of contacts.

Jerry, KE7ER


On Fri, Apr 9, 2021 at 11:24 AM, jerry@... wrote:
Hello all!

QRZ, is the frequency in use?

Last night, on a whim, I ordered a uBITX v6 from India. Anybody know how fast they ship? Kicking myself this morning because it's also carried by gigaparts, which would surely get it to me faster :).

My name is Jerry, callsign KF6VB. I've been a ham since 1970 or so. Never been
much good at CW, but I did earn the extra with code in the mid-80's. My interests
are homebrewing and ragchewing. Not much for contesting - which seems to leave me out of most ham activity these days. I have a solid technician-level background in electronics and a 20 year career in embedded software engineering.

At this time, I have a 6BTV vertical up the hill behind my house. It is grounded with an "Ufer ground", which is about 80 feet of 6-gauge copper wire embedded in the concrete pad. The pad is ten feet wide by 70 feet long. The vertical is fed by an automated MFJ998RT remote autotuner. The tuner was needed because the coax down to the house is 300 feet! The Ufer ground is extremely effective - so much so that
the tuning on 80M was too low, and I had to chop about a foot off the top whip - directly contravening the dictates of the manual.

I am already thinking about upping the power. QRP is fun in principle, but
I've found it quickly becomes frustrating ( and not conducive to ragchewing ) when people don't hear me. Ebay is crawling with cheap linear amplifier cards and kits. I see one vendor who has a three-board kit including the per-band low pass filters and Tx/Rx switching. The one I'm looking at is 600W. That's a good power level IMHO - only a few dB below legal limit, and easily drivable from a standard 125VAC outlet.

- Jerry KF6VB
New Member intro

[email protected]
 

Hello all!

QRZ, is the frequency in use?

Last night, on a whim, I ordered a uBITX v6 from India. Anybody know how fast they ship? Kicking myself this morning because it's also carried by gigaparts, which would surely get it to me faster :).

My name is Jerry, callsign KF6VB. I've been a ham since 1970 or so. Never been
much good at CW, but I did earn the extra with code in the mid-80's. My interests
are homebrewing and ragchewing. Not much for contesting - which seems to leave me out of most ham activity these days. I have a solid technician-level background in electronics and a 20 year career in embedded software engineering.

At this time, I have a 6BTV vertical up the hill behind my house. It is grounded with an "Ufer ground", which is about 80 feet of 6-gauge copper wire embedded in the concrete pad. The pad is ten feet wide by 70 feet long. The vertical is fed by an automated MFJ998RT remote autotuner. The tuner was needed because the coax down to the house is 300 feet! The Ufer ground is extremely effective - so much so that
the tuning on 80M was too low, and I had to chop about a foot off the top whip - directly contravening the dictates of the manual.

I am already thinking about upping the power. QRP is fun in principle, but
I've found it quickly becomes frustrating ( and not conducive to ragchewing ) when people don't hear me. Ebay is crawling with cheap linear amplifier cards and kits. I see one vendor who has a three-board kit including the per-band low pass filters and Tx/Rx switching. The one I'm looking at is 600W. That's a good power level IMHO - only a few dB below legal limit, and easily drivable from a standard 125VAC outlet.

- Jerry KF6VB
Re: uBitx V6 - schematics

 

Correction to earlier post.? It does appear that on the uBITX schematics,
some leads are marked with an "x", but as Raj has said, they are not
connected to anything else.

Arv
_._


On Fri, Apr 9, 2021 at 10:46 AM Arv Evans via <arvid.evans=[email protected]> wrote:
In conventional schematics it is sometimes necessary to show connections
as an "x" or something similar.? This is because showing the connection
between two points might excessively complicate the drawing.? There should
be another "x" somewhere else on the drawing.? This is the continuation of
the wire or PC trace that you noticed was marked as "x".? In other words, the
two "x" are tied together.

Arv
_._


On Fri, Apr 9, 2021 at 1:44 AM Pierre Guillot <jb.gallauziaux@...> wrote:
Could a member explain these odd things I find on the schematics wiring of four transformers :
- T5 : wires 1 and 6 end in a x ;
- T6 : the same ;
- T8 : the same ;
- T11: the same with wires 3 and 4.

73 - Pierre - FK8IH?

Re: uBitx V6 - schematics

 

In this case, an "x" means no connection.

In the uBitx schematics, the remote connections that Arv describes?
are drawn as text inside a box with a pointy end.
An example of this is "CLK2" in the upper left of the schematic.

Jerry, KE7ER


On Fri, Apr 9, 2021 at 09:46 AM, Arv Evans wrote:
In conventional schematics it is sometimes necessary to show connections
as an "x" or something similar.? This is because showing the connection
between two points might excessively complicate the drawing.? There should
be another "x" somewhere else on the drawing.? This is the continuation of
the wire or PC trace that you noticed was marked as "x".? In other words, the
two "x" are tied together.
?
Arv
_._
?
Hide quoted text

?


On Fri, Apr 9, 2021 at 1:44 AM Pierre Guillot <jb.gallauziaux@...> wrote:
Could a member explain these odd things I find on the schematics wiring of four transformers :
- T5 : wires 1 and 6 end in a x ;
- T6 : the same ;
- T8 : the same ;
- T11: the same with wires 3 and 4.

73 - Pierre - FK8IH?
Re: uBitx V6 - schematics

 

In conventional schematics it is sometimes necessary to show connections
as an "x" or something similar.? This is because showing the connection
between two points might excessively complicate the drawing.? There should
be another "x" somewhere else on the drawing.? This is the continuation of
the wire or PC trace that you noticed was marked as "x".? In other words, the
two "x" are tied together.

Arv
_._


On Fri, Apr 9, 2021 at 1:44 AM Pierre Guillot <jb.gallauziaux@...> wrote:
Could a member explain these odd things I find on the schematics wiring of four transformers :
- T5 : wires 1 and 6 end in a x ;
- T6 : the same ;
- T8 : the same ;
- T11: the same with wires 3 and 4.

73 - Pierre - FK8IH?

Re: uSDX

 

I like building and have built a BITX 40, uBITX, QCX, QCX mini and a Barb WB2CBA v1.02 uSDX. The first thing to know is that unlike the uBITX or QCX, there are several hardware variants with different capabilities and technology (SMD vs through hole). If you are interested, spend a little time thinking about what development track you want to build.

I posted a few articles on the uSDX here

and here

and the groups.io WIKI is useful.

BTW - if you are interested in SDR check this out:

note this talk "Ashhar Farhan VU2ESE - sBITX - An Open Source SDR that YOU can hack!"

--
? 73
??? Bob? KD8CGH
Re: uBitx V6 - schematics

 

Pierre,

It means that those windings are not connected.

HFSignals winds all transformers identically. In places where a bifilar (2 windings) is required
they leave the 3rd winding disconnected. It makes the manufacture parts list simpler.

Raj, vu2zap

At 09/04/2021, you wrote:
Could a member explain these odd things I find on the schematics wiring of four transformers :
- T5 : wires 1 and 6 end in a x ;
- T6 : the same ;
- T8 : the same ;
- T11: the same with wires 3 and 4.

73 - Pierre - FK8IH
uBitx V6 - schematics

Pierre Guillot
 

Could a member explain these odd things I find on the schematics wiring of four transformers :
- T5 : wires 1 and 6 end in a x ;
- T6 : the same ;
- T8 : the same ;
- T11: the same with wires 3 and 4.

73 - Pierre - FK8IH?
Re: uSDX

Pierre Guillot
 

uSDX enclosure :?
73 - Pierre - FK8IH
Re: uSDX

 

Robert - That's about what I was figuring, definitely no more than that and maybe less.? I already have a few Nanos since I couldn't use them on the Raduino with the header soldered on opposite and also have a couple of the clock boards so just need to put in an order to mouser or DIgiKey for the pieces-parts I don't have.? That will probably have to wait until fall as I am heading to the OK mountains next Saturday and won't be back to the home QTH until fall.? If the boards don't get here before I leave I'll have the XYL carry them up with her in May and I can mail them from the cabin.

73,

Justin B.
KI5GKD
Re: UBITX V6 My Way!! - ATU integration #nextion #ubitxv6

 

My PICKit 3 programmer should be here Saturday so I'll let you know how it goes, if I don't brick it!
Re: Many uBitx's have reduced power on 40m CW

 

The phases I gave in the post included below for the various impedances?
when doing an AC Analysis in LTSpice of the Q90 uBitx stage are incorrect.

When LTSpice measures current through a device, it assigns a seemingly arbitrary direction to the current.
In the case of my AC voltage source, it assumed current was going into the top node, not out.
To show a correct phase in such a case, we must add a negative to the formula used in the plot.

For example, assume node n001 is the wire from the top of voltage source Vsrc to our network under analysis.
V(n001) is the voltage at that node, and I(Vsrc) is the current through the voltage source, so the impedance should be V(n001)/I(Vsrc)
But if that current is going the wrong direction, the formula should be modified to? -V(n001)/I(Vin)
The math used for evaluating that impedance is in the complex plane, using complex arithmetic.
? ??
Multiplying (or dividing) by a -1 is equivalent to a phase shift of 180 degrees.

For example, in a previous post I stated:

<? For the v3 configuration with C81=0.1uF and R83=2.2ohms, my simulation shows that
<? the Q90 stage has an input impedance of 51 ohms to 45 ohms, at 173 to 165 degrees
<? Voltage gain ranges from 4.5 to 3.65.
<? These values are for a range of 3.5mhz to 30mhz, in that order, Q90 stage has a load of 50 ohms.

Instead of a phase shift of 173 to 165, we have a phase shift of 180-173=7 degrees to 180-165=15 degrees.
Which is reassuring, since a phase shift of zero degrees would indicate a pure resistance, these values are slightly inductive.
The original phase shifts given don't make much sense for an impedance, it should always be somewhere between
+90 degrees for a pure inductance and -90 degrees for a pure capacitance.

Jerry, KE7ER




On Tue, Apr 6, 2021 at 11:07 AM, Jerry Gaffke wrote:

Given the variation in impedance as seen in the simulations of ideal components,
it's amazing to me that the output power manages to be as flat as it is.
Fun to figure out what all is going on here, more than it might seem at first.

From a practical standpoint, Curt's bigger C81 strikes me as the best fix,
for those that care about the slightly reduced power when operating 40m CW.
But with C81 too big, the difference in output power between 3.5mhz and 30mhz
may become too extreme.

For the v3 configuration with C81=0.1uF and R83=2.2ohms, my simulation shows that
the Q90 stage has an input impedance of 51 ohms to 45 ohms, at 173 to 165 degrees
Voltage gain ranges from 4.5 to 3.65.
These values are for a range of 3.5mhz to 30mhz, in that order, Q90 stage has a load of 50 ohms.

On v4, R83 was moved to 2.2 ohms for more gain.? ?
Input impedance dropped to a range of 18 to 19 ohms, 170 to 183 degrees.
Voltage gain ranges from 5.5 to 6.7.?

On v5,v6 the cap at C81 was moved to 470pF so high frequencies have more gain than low frequencies,
this compensates for losses at high frequencies in the various power amp stages.
Input impedance now ranges from 200 ohms to 45 ohms at 150 to 100 degrees.
Voltage gain for the Q90 stage runs from 1.0 at 3.5mhz to 5.5 at 30mhz.

The v3 configuration is likely the best as far as giving the filter and mixer a proper 50 ohm load.
But we needed more gain at higher frequencies to get sufficient power out,
without too much drive on 3.5mhz.

I haven't analyzed the effect of the Q90 impedance phase angle
on how the filter or mixer might behave.

Jerry, KE7ER
Re: uSDX

 

Hi Justin,

That article looks interesting. I wouldn¡¯t mind buying one of the PCB¡¯s off of you. How does $5.00 sound, is that fair? I usually look at this group each day so let me know what you think.

73,
Robert, AG6LK?
Re: Many uBitx's have reduced power on 40m CW

 

Jerry,

I agree with your assessment.? I really need to do the IMD and power tests for SSB.

Doing some more simulation, I do believe that increasing R83 to allow for a better filter impedance match is probably a good thing.? The 10 ohms with 1nF C81 seems to be the best but does reduce the total output.?

Thank you again for the input.
73
Evan
AC9TU
30441 - 30460 of 117018