Re: Harmonics measured by Warren. How bad?

#57978

Yes. I remember those old HP analyzers well...along with the poloroid camera for taking screen shots. Yes, a tight resolution BW is essential. When I worked at the monitoring station back in the late 70s and early 80s, we used to measure HF military multitone teletype circuits. 16 encrypted circuits (32 distinct frequencies) on a single voice channel. We had to tighten the res bw up as tight as it would go and use a really slow sweep. Good luck!

Re: End Fed antennas w/ uBITX #ubitx

#57977

ARV,

I agree, the attention span is short.

Close the thread, copy it there.? Then kill the new one Bo started.

Allison

Re: #ubitx. Great EFHW group on Facebook

#57976

Bo I guess you missed the 320 or so positings here about EFHW antennas.

Allison

Re: Harmonics measured by Warren. How bad?

#57975

you need a two tone source and that can be just a few trasistor and I think Elecraft sells a small one.

2T-gen 2-Tone Test Oscillator? looks like 80$

Learn the SA as you will need to get slow scans at fairly narrow bandwidths 300Hz RBW and 10khz VBW.

Span is narrow as you only want to catch less than +-10khz of carrier.??
THe procedure is describe in the ARRL Lab and on line.

Now your ready...

Allison

Re: Right-sided relay harmonic attempted fix for v3/4 ubitx

Gordon Gibby

#57974

8/27/2018.? ?Here are the baseline data.? ?Unmodified uBitx with RV1 roughly in the middle, 7Ahr battery, producing about 11.5 V under load.? RG8X to Micronta SWR/"pwr" meter RG8X to Heathkit Cantenna with 50 db tap (16K/50 ohms) then double shielded coax to a 20 dB BNC pad to my ICOM718 (shares transceiver).? ?Each signal tuned for maximum S-meter.? ?CW only mode tested.? ? ?S0 means I could hear it, but no reading on S meter
The S9+30dB reading today at fundamentals is slightly higher than the S9+25 previously seen -- room is warmer???

Freq? ? ?Meas? Fundamental? ? ?2ndHar? ? ?3rdHarm? ? ? 4thHarm? ? 5thHarm? ? ? 6thHarm? ? 7thHarm
3.505? ? 5W? ? ?S9+30 dB? ? ? ? S7.5? ? ? ? ? ?S8.5? ? ? ? ? ? S0? ? ? ? ? ? ?S8? ? ? ? ? ? ? ?S0? ? ? ? ? ? ?S8.5
7.005? ?2.5W? ?S9+30 db? ? ? ? S0? ? ? ? ? ? ? S8.5? ? ? ? ? ? S5.5*? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?* = wavering signal level
9.995? ?1.5W? ?S9+30 db? ? ? ? S0? ? ? ? ? ? ? S9
14.005 1W? ? ? S9+30 db? ? ? ? S0

Now to build the "daughterboard" relay system.? ?My plan is to connect it first by the most simplest? of connections, with just "wires", reasonably neatly, and short, but not shielded and nothing fancy.? ?Then see whether/what improvement there is.

? ?

Re: Harmonics measured by Warren. How bad?

#57973

开云体育

Allison,

Thanks.? I have another question for you RE IMD but I have to put some data together first.? BTW just got my spec anal a couple of weeks ago.? Still in learning mode.? Last experience with a spec anal was back in the ‘70s and ‘80s with HP8566 and HP3561 and 3562.? The latter being used in a laboratory High Range Resolution Radar.

Mike

K5ESS

?

Show quoted text

From: [email protected] [mailto:[email protected]] On Behalf Of ajparent1/KB1GMX
Sent: Monday, August 27, 2018 2:33 PM
To: [email protected]
Subject: Re: [BITX20] Harmonics measured by Warren. How bad?

?

K5ESS

Looing at the your SA....

You have to use narrower RBW to see things like IMD and other more detailed artifacts.
That also means slowing the sweep...

For harmonics, looks decent!

Allison

Re: End Fed antennas w/ uBITX #ubitx

Vince Vielhaber

#57972

The frustration comes in that the End Fed discussion was quite long and an antennas group came out of it.  The discussion and arguments should've moved there but people keep reviving it here.  While it's true that some people use an end fed on their ubitx, I don't.  I use one on my Kenwood while camping and have one here for 40-10 for whatever rig I happen to be using for a base station.

Vince - K8ZW.

Show quoted text

On 08/27/2018 04:35 PM, iz oos wrote:
I have been following this thread from the beginning, there was an
interesting debate other than fun at times with seemingly opposite
views. I don't see where frustration could come from this thread. Was it
related to uBitx? Partly yes, some Ubitx users use this antenna, others
like me want to understand what is inside the black box transformer. And
as this antenna operates with a satisfactory efficiency on the harmonics
too, a uBitx user has to take this into account.


Il 27/ago/2018 21:00, "Arv Evans" <arvid.evans@...
<mailto:arvid.evans@...>> ha scritto:

    Guy WB7SZI

    The "antennas" group was started out of frustration with the ongoing
    going on about
    end-fed antennas.  Starting that group was partly in hopes that the
    end-fed discussion
    might move there, and partly as a social experiment to see if it
    would move.  Now there
    are end-fed discussions on both the BITX group and on the antennas
    group.  Not sure
    if that is progress or a comment on social aspects of discussion groups.

    Arv  K7HKL
    _._




    On Mon, Aug 27, 2018 at 10:16 AM Guy N7BIR <sgbridge@...
    <mailto:sgbridge@...>> wrote:

        Why are we still having discussions on End Fed Antennas? Thought
        that was why the Antenna email list was started.
        Cheers,

        Guy WB7SZI

-- 
  Michigan VHF Corp.      
                          

Re: End Fed antennas w/ uBITX #ubitx

#57971

I have been following this thread from the beginning, there was an interesting debate other than fun at times with seemingly opposite views. I don't see where frustration could come from this thread. Was it related to uBitx? Partly yes, some Ubitx users use this antenna, others like me want to understand what is inside the black box transformer. And as this antenna operates with a satisfactory efficiency on the harmonics too, a uBitx user has to take this into account.

Show quoted text

Il 27/ago/2018 21:00, "Arv Evans" <arvid.evans@...> ha scritto:

Guy WB7SZI?

The "antennas" group was started out of frustration with the ongoing going on about
end-fed antennas.? Starting that group was partly in hopes that the end-fed discussion
might move there, and partly as a social experiment to see if it would move.? Now there
are end-fed discussions on both the BITX group and on the antennas group.? Not sure
if that is progress or a comment on social aspects of discussion groups.

Arv? K7HKL
_._

On Mon, Aug 27, 2018 at 10:16 AM Guy N7BIR <sgbridge@...> wrote:
Why are we still having discussions on End Fed Antennas? Thought that was why the Antenna email list was started.?
Cheers,

Guy WB7SZI?

#ubitx. Great EFHW group on Facebook

Bo Barry

#57970

?Sorry I sidetracked things here. It was meant to be a simple 'ad' to inform the group about a great antenna for our rig.
There is an excellent group on Facebook and just Google Steve Ellington on YouTube and you will get ALL your answers.
Let's get our little ubitx's fine tuned on this forum instead

Bo W4GHV?

Odd Raduino, How do I Connect it? #bitx40

#57969

Hi,?
In the kit was a Raduino that seems to be adopted for uBitx. Anyone who know which pins to use when connecting to the board?

Regards
Arne SM7ECA

1991487A_4995_4E98_AC89_5E32D7BC3CA0.jpeg

sub-harmonic mixer BITX harmonics and spurs

#57968

I wonder if anybody has considered using sub-harmonic mixers in BITX, and

what the effect might be on harmonics and spurs?

Arv
_._

Re: Harmonics measured by Warren. How bad?

#57967

K5ESS

Looing at the your SA....

You have to use narrower RBW to see things like IMD and other more detailed artifacts.
That also means slowing the sweep...

For harmonics, looks decent!

Allison

Re: Harmonics measured by Warren. How bad?

#57966

开云体育

Re-measured at a different FT8 frequency.? With o-scope 50v p-p for 6.25 W.? With spec anal 38.5 dBm 0r 7 watts.? Assumes that tracking generator is accurate at 0dBm out.

Mike

K5ESS

?

Show quoted text

From: [email protected] [mailto:[email protected]] On Behalf Of K5ESS
Sent: Monday, August 27, 2018 2:02 PM
To: [email protected]
Subject: Re: [BITX20] Harmonics measured by Warren. How bad?

?

Iz oos,

Well at 13.8V, 1.2A in (16.6W) and 9.5 out it looks like around 57% efficiency.? I’ll defer to the experts as to whether that is reasonable or if I need to re-verify the power out.? As far as the shape of the fundamental,? the side lobes are below -43 dB but again I defer to the more knowledgeable.? Comments appreciated as well as suggestions for further test.

Mike

K5ESS

?

From: [email protected] [mailto:[email protected]] On Behalf Of iz oos
Sent: Monday, August 27, 2018 1:37 PM
To: [email protected]
Subject: Re: [BITX20] Harmonics measured by Warren. How bad?

?

Mike, does it draw only 1.2A for almost 10w output? It seems complaint as regards the 3rd harmonics but is that fat bell shape around the fundamental complaint as well?

?

Il 27/ago/2018 19:41, "K5ESS" <k5ess.nothdurft@...> ha scritto:

My uBitx (no mods) seems to be compliant on 20M SSB FT8 at around 9.5 W out (13.8V @1.2A in)

Mike

K5ESS

?

Re: CW with new build uBITX

#57965

You can get rid of the CW resistor divider kludge.? Look at software at

Show quoted text

On August 27, 2018 at 3:23 PM Arv Evans <arvid.evans@...> wrote:

Matthias DD7NT

You can check the CW pin input to its ADC by connecting a reasonably high impedance voltmeter
to the pin and then reading voltage while sending (1) straight key closed, (2) dit closed, and (3) dah
closed.? Each of these should give a different voltage to the CW input ADC pin.? The ADC reads
these voltages and the Arduino decides what to send if these voltages are lower than the +5V
supply.? There is some small range for each voltage to allow for resistor tolerance.?

Closure of the straight key should show zero volts on the CW input.
Closure of the dah paddle should show 3.4 volts on the CW input.
Closure of the dit paddle should show 1.6 volts on the CW input.
Voltage readings are approximate and there is some small range allowed to compensate for that.

< >

Arv? K7HKL
_._

Re: Harmonics measured by Warren. How bad?

#57964

K5ESS,

57% is good efficiency.?

The side lobes close to the carrier (those RE IMD and -26dbc is in the good enough range)
can be higher but harmonics?should be less than -43dbc.

Generally with median efficiency there is limited correlation to harmonics.? IMD however?
can move up or down depending on a lot of factors both amplifier related and the
stages prior.

Allison

Re: CW with new build uBITX

#57963

Matthias DD7NT

You can check the CW pin input to its ADC by connecting a reasonably high impedance voltmeter
to the pin and then reading voltage while sending (1) straight key closed, (2) dit closed, and (3) dah
closed.? Each of these should give a different voltage to the CW input ADC pin.? The ADC reads
these voltages and the Arduino decides what to send if these voltages are lower than the +5V
supply.? There is some small range for each voltage to allow for resistor tolerance.?

Closure of the straight key should show zero volts on the CW input.
Closure of the dah paddle should show 3.4 volts on the CW input.
Closure of the dit paddle should show 1.6 volts on the CW input.
Voltage readings are approximate and there is some small range allowed to compensate for that.

<>

Arv? K7HKL
_._

Re: CW with new build uBITX

James Lynes

#57962

I believe there are posts somewhere talking about diagnostic code you can load.

If not, write a little program to read the analog bits and display on the serial monitor. Then you can see what the Nano is seeing.

James

Re: Right-sided relay harmonic attempted fix for v3/4 ubitx

Gordon Gibby

#57961

hmmm..... looks like I got lost trying to retype them.....

enclosed is the actual pdf I'm using as a data gathering sheet....harmonics were created by a spreadsheet.

________________________________________
From: [email protected] <[email protected]> on behalf of Vince Vielhaber <vev@...>
Sent: Monday, August 27, 2018 3:02 PM
To: [email protected]
Subject: Re: [BITX20] Right-sided relay harmonic attempted fix for v3/4 ubitx

yep, the 3rd for 80 meters

Vince.

On 08/27/2018 02:58 PM, Gordon Gibby wrote:
Hmm.... don't know where the 175.525 came from????
Any others look suspect to you?

________________________________________
From: [email protected] <[email protected]> on behalf of Vince Vielhaber <vev@...>
Sent: Monday, August 27, 2018 2:44 PM
To: [email protected]
Subject: Re: [BITX20] Right-sided relay harmonic attempted fix for v3/4 ubitx

Are these typos or is your math really that bad?

Vince.

On 08/27/2018 09:14 AM, Gordon Gibby wrote:
I'm expecting to be able to make real baseline measurements tonight.
 My receiver (Icom 718) cannot really go past 30 Mhz so I'm restricted
to measuring harmonics' strengths below that frequency.

So here are my plans for measuring.   For the 30 meter band, since I'm
on dummy loads (no signfiicant radiation) I'm going to sneak slightly
UNDER 10 MHz so I can catch the important 3rd harmonic on the ICOM 718:

Fundamental   2Har        3Har        4Harm     5Harm     6Harm     7Harm
3.505MHz       7.010       15.515    14.020     175.525  21.030     24.535
7.005            14.010       21.015    28.020
9.995            19.990       29.985
14.005          28.010

Although that doesn't cover all the bands, the problem on the higher
bands shifts to spurs, which the Low Pass  Filters aren't as well
targeted at --- but hopefully with just these baseline measurements, the
proof-of-concept of simple-minded daugherboard addition of a separate
relay to avoid relayccontact-to-relaycontact blow-pass will be either
proven or disproven.

I had hoped to make these measurements this morning but was not able to
get that done  before going back to work.  I have the next several days
"off" so this may speed up.

Cheers,
gordon
--
   Michigan VHF Corp.      

--
   Michigan VHF Corp.      

HarmonicMeasurementReportingForm.pdf

Re: Right-sided relay harmonic attempted fix for v3/4 ubitx

Vince Vielhaber

#57960

yep, the 3rd for 80 meters

Vince.

Show quoted text

On 08/27/2018 02:58 PM, Gordon Gibby wrote:
Hmm.... don't know where the 175.525 came from????
Any others look suspect to you?

________________________________________
From: [email protected] <[email protected]> on behalf of Vince Vielhaber <vev@...>
Sent: Monday, August 27, 2018 2:44 PM
To: [email protected]
Subject: Re: [BITX20] Right-sided relay harmonic attempted fix for v3/4 ubitx

Are these typos or is your math really that bad?

Vince.

On 08/27/2018 09:14 AM, Gordon Gibby wrote:
I'm expecting to be able to make real baseline measurements tonight.
 My receiver (Icom 718) cannot really go past 30 Mhz so I'm restricted
to measuring harmonics' strengths below that frequency.

So here are my plans for measuring.   For the 30 meter band, since I'm
on dummy loads (no signfiicant radiation) I'm going to sneak slightly
UNDER 10 MHz so I can catch the important 3rd harmonic on the ICOM 718:

Fundamental   2Har        3Har        4Harm     5Harm     6Harm     7Harm
3.505MHz       7.010       15.515    14.020     175.525  21.030     24.535
7.005            14.010       21.015    28.020
9.995            19.990       29.985
14.005          28.010

Although that doesn't cover all the bands, the problem on the higher
bands shifts to spurs, which the Low Pass  Filters aren't as well
targeted at --- but hopefully with just these baseline measurements, the
proof-of-concept of simple-minded daugherboard addition of a separate
relay to avoid relayccontact-to-relaycontact blow-pass will be either
proven or disproven.

I had hoped to make these measurements this morning but was not able to
get that done  before going back to work.  I have the next several days
"off" so this may speed up.

Cheers,
gordon
--
   Michigan VHF Corp.      

-- 
  Michigan VHF Corp.      
                          

Re: Right-sided relay harmonic attempted fix for v3/4 ubitx

Gordon Gibby

#57959

开云体育

That procedure [adjusting attentuators until S meter reads same]??would work fine, but I'm dealing with BNC pad attentuators and physically switching them all around is tedious and I can't keep the transmitter going that long I suspect.

So the real GOAL here is to see WHAT DIFFERENCE is made by adding in a right-sided relay system....so just getting intial and 'after'? measurements probably suffices, but to try and "calibrate" the s-meter I ran through every attentuator I had and calibrated it as best as I could, so I actually have SOME idea where the FCC regulation requirement truly is as well...

I'm just doing CW as others have already shown that the SSB has leser / differnt problems.....and my target is the layout of the low pass filters, not the odd products found from the mixer systems....can't fix those with my little modification....

hope that helps!

gordon

Show quoted text

From: [email protected] <[email protected]> on behalf of ajparent1/KB1GMX <kb1gmx@...>
Sent: Monday, August 27, 2018 2:55 PM
To: [email protected]
Subject: Re: [BITX20] Right-sided relay harmonic attempted fix for v3/4 ubitx

?

Tom wb6b and all,

Agreed its rare for a S meter to be accurate save for maybe one point.
I usually set for 50uV as S9 if reasonable for the radio other its random.

Usually when using a receiver for a check I pick a meter indication and?
note what it takes (from an attenuator) to get that reading then change
the source and see what the difference in the setting of the attenuator?
to get he same reading.? ?That is the gain or loss.? Works with a diode
detector or crappy radio or even a good one.? As the detector(radio) is
not calibrated and the set point such as S9 is reproducible but the
attenuator can be.

That procedure is old as dirt and makes no reliance on the radio
or its meters calibration.

Allison