Date   
Re: Harmonic performance - SSB vs CW

Kees T
 

Warren, 

That is great that you tested the coils you removed from the uBITX on a perf board. Were the capacitors also the ones off the uBITX board ? If not, could you add those to your test (I know that asking is a lot easier than doing). You would like to completely duplicate what is on the uBITX board.

As far as it being a layout problem, contact resistance, added wiring capacitance and the actual parts used would be the determining factors. 

This is what I posted on the other thread:
I just looked at the uBITX schematic for 2017 (I believe it to be level V3) and looked how the band switching of 4 LPFs is done with 3 Relays KT1 - KT3. I'm told V4 is the same.

The 3 relay control signals are TXA (KT1), TXB (KT2), and TXC (KT3) which come from the Raduino board.  

The 4 stages of TXA/TXB/TXC are (0 indicates relay not "picked", 1 indicates relay "picked") : 
0,0,0 which selects the High Band LPF and uses 3 series relay contacts, 
1,0,0  which selects the Hi Midband LPF and uses 5 series relay contacts.
1,1,0  which selects the Lo Midband LPF and uses 7 series relay contacts
1,1,1 which selects the Low Band LPF and uses 7 series relay contacts.

That's a lot of series (resistive) relay contacts and associated (capacitive) wiring. Adding one more relay,  and associated driver, could cut that down to a max of 2 series relay contacts for each band (one on Input and 1 on Output) and "bus" type LPF wiring (results in less overall wiring). 

73 Kees K5BCQ

Re: Humble suggestion future Ubitx versions #ubitx

AA9GG
 

We are hams...it's NOTHING to build a filter to put on it....It is sold as a "kit"...so FINISH building it and stop complaining....

On Mon, Aug 6, 2018 at 12:59 PM, RICHARD <k6kwq@...> wrote:

Last month QST did a write up on the BITX40, with all the published lab tests.  It would be interesting if they were do the same with the uBitx.    It might get FCC attention and stop all future imports to the USA,  is that what we want?  Maybe it is time to tone down all the attention to these problems.

Just a thought.

K6KWQ

 

Sent from Mail for Windows 10

 


From: BITX20@groups.io <BITX20@groups.io> on behalf of ajparent1/KB1GMX <kb1gmx@...>
Sent: Monday, August 6, 2018 9:30:20 AM
To: BITX20@groups.io
Subject: Re: [BITX20] Humble suggestion future Ubitx versions #ubitx
 
Iz oos,

For some its was the FT817 for 109$.  There is a lot of distance and people complain about the FT817!

I also agree if you transmit, do so cleanly.  Its a kindness to friends around the world  The bitx40 is far cleaner.

As to many rigs... guilty.

For hf I have two old Tentec the 505 QRP 5 band and its bigger brother the 340 100W 5 band.
I have no worries depite the fact they were design in the 19070s that they meet current standards
or maybe even exceed them.

More modern a Ft817 and the Tentec Eagle.

That and KNQ7A, KD1JV Slopbucket20, WM20, and Diz's 1W, for the
kit radio world.  Then I have my first 20M SSB , 10M SSB, 15M SSB,
radios from the ground up.  All meet the numbers required and then some.
All have decent carrier suppression.  The only one with issues that needed
help was the KNQ7A that being a really loud pop on TX, easy fix too.

Others manage to do it well and inexpensively and with attention it works.
As is the ubitx has more of my time in it than a few scratch builds including
building their  filters and PLL systems(pre Si 5xx parts).

Mine however is in the "junkbox" as a result of slicing it up to get to root causes.
Its salvageable but a clean sheet would be less time consuming.

Allison




--
Paul Mateer, AA9GG
Elan Engineering Corp.
www.elanengr.com
NAQCC 3123, SKCC 4628

Re: Harmonic performance - SSB vs CW

Warren Allgyer <allgyer@...>
 

The reason I mention PIN diodes is these are used in the pristine RS-HFIQ SDR which is a superb all band performer. A significantly higher price point and it is not a standalone. But it is a superb radio and it uses PIN diodes for its filter switching. Yes there is significant current drain but there is also relay holding current in this design. Not advocating PIN, simply raising the possibility.

WA8TOD

Re: Harmonic performance - SSB vs CW

Tom Cooper
 

I don't have much in the way of test equipment, so I did a simple experiment using my T-T Eagle and uBITX V3.  I set both radios to 3.510 MHz, attached both radios to a Top Ten Devices "A/B station selector" via RG-58 jumpers of the same length and connected a dummy load to the uBITX.  With 5 watts out of the uBITX the Eagle showed a strength of 5 on the s-meter.  The isolation of the A/B selector is not half bad.

When I changed the Eagle to 7.020 MHz, I could hear the 2nd harmonic weakly with no s-meter reading.  Listening at 10.530 I could hear the 3rd harmonic a little stronger than at 7.020 and got the smallest s-meter reading possible, one little box on the Eagle display.  I could hear nothing at the other harmonics.

Next, I got my trusty Argo 509 out of the closet and repeated the experiment with it also set to 5 watts out.  I could hear it on the Eagle through the 5th harmonic, and it was noticeably louder than the uBITX at 7.020 and 10.530.

This actually proves nothing, of course, but it does tell me that I am not doing anything worse than I have been doing for over 30 years by using the uBITX.  If an improvement is found for either of these radios, and doesn't require a major rebuild, I will certainly adopt it.  In the meantime I think I'll ask a local ham buddy to listen while I transmit using an antenna and see if he hears anything objectionable.  If anyone from this group would like to try that also just email me for a sked.

73,

Tom  W1EAT

Re: Nextion Displays >> warning

Joe
 

Eric,

I have both 3.2 E and Non E 7 inch versions.
They both work well and response on the the display is instantaneous .
The E version is faster , has a RTC , generally higher memory and battery backup for the RTC but as far as operational performance I see no discernible difference. The E cost more and if money is no object - the E have more features.

When uploading a program from the micro sd to the Nextion E versions are much faster, however,, from then on the perform is the same.
The biggest thing I look for is what physical size I would like and what is the resolution I want. 
 This is dependent on display size.
My 7 inch is 800 /480 while the 3.2 is 400/240..

Either way, they all perform well and  display quickly..... 


Joe
VE1BWV


On Mon, Aug 6, 2018 at 4:45 PM <e.berman@...> wrote:
Joe

Did you see any difference between the Enhanced and the basic? Was wondering which one to buy?

Thank you
Eric
KC3GDV

Re: Need Help

bdunk@...
 

Thanks Jack,

I'm not sure what you are talking about, I just assumed I install the replacement encoder and it should work.

Where do I fine the 4.3 software?

Best regards, Bert VE3TYS

Re: Harmonic performance - SSB vs CW

ajparent1/KB1GMX <kb1gmx@...>
 

Warren.

I'd think patching would work well, its by far the cleanest.

To relays, separate ones at opposing ends of each filter. I think that's a must. 

Pin diodes the problem is ones available that work at HF at up to 20W and the
standing current to switch them are likely scarce or expensive.  I have done
that for a dual band at UHF compact and clean.  

Allison

 

Re: Need Help

Jack, W8TEE
 

Have you tried running an example encoder problem from the encoder library you're using? If it's wired correctly, it should perform as expected. You can always reload the 4.3 software.

Jack, W8TEE

On Monday, August 6, 2018, 4:14:15 PM EDT, <bdunk@...> wrote:


Hi again Allison,

I replaced the encoder with a new one from Digi-Key and still had the problem.

Where do I find 4.3 and how do I install it?

Cheers,

Bert

Re: Need Help

bdunk@...
 

Hi again Allison,

I replaced the encoder with a new one from Digi-Key and still had the problem.

Where do I find 4.3 and how do I install it?

Cheers,

Bert

Re: Harmonic performance - SSB vs CW

Warren Allgyer <allgyer@...>
 

Understood Allison. I do not expect any design that routes input and output through the same relay will be satisfactory due to capacitive coupling in the relay and necessary proximity of IO to get to the relay. I think the only viable switching would be separate relays (or PIN diodes) for input and output and separated physically by the filter itself. 

I actually plan to migrate the other three filters over to this over to this board and use it without switching; manually patching the required filter. WA8TOD 

Re: Nextion Displays >> warning

e.berman@...
 

Joe

Did you see any difference between the Enhanced and the basic? Was wondering which one to buy?

Thank you
Eric
KC3GDV

Re: Need Help

ajparent1/KB1GMX <kb1gmx@...>
 

Assuming your evaluation of the wireing is sound the problem is either bad encoder, testable with ohmmeter
disconnected from raduino. 

Or raduino issue.  Two possible are reload the software, if it starts working great.  Or it doesn't, bad input pin.

I'd go with 4.3 as it has a few improvements.  Your call.

Allison

Re: Harmonic performance - SSB vs CW

ajparent1/KB1GMX <kb1gmx@...>
 

Warren,

Good, I didn't have time to try that. 
Though a lesser filter from a different radio convincedme it was
relays and layout.

However while it confirms bad layout it didn't test the relay contact
part of the layout issue.  We need that to confirm if the open contact
capacitance (isolation) will corrupt the filter performance.

The give away is the fact that the filter parts and characteristics are
good but blow by is a significant part of the problem.

Allison

Re: Harmonic performance - SSB vs CW

ajparent1/KB1GMX <kb1gmx@...>
 

Kees,

Parts were tested.  Reason, one of the samples had a defective set of coils for the 7mhz filter.
I have the schematics enlarged and printed out.

Allison

Re: Need Help

bdunk@...
 

Good afternoon Allison,

 

I still need help!

 

I’m still having experiencing difficulties getting up and running. I rechecked all the wiring, replaced the 8 pin connectors and checked for cold solder joints. I see that the POW and the L led on the nano board are illuminated red. 

 

Any thoughts on what might be happening, does the sketch need to be reloaded what is the sketch that is being used with the uBITEX V4.3?

 

Best regards,

Bert VE3TYS

Re: Nextion Editor for Linux Mint ??

SV9CVJ Nikos
 

Dear Tom, thank you very much for the help. I installed Mono and Wine on my pc but I can't run the Nextion Editor. I will try with Segnix, that is for Raspberry.

Re: microphone

Henning Weddig
 

Folks,

the mic amp can not work! WHY??

Please have a look on the shcematic: the "high impedance output" of the mic amp (let´s assume R65 is the output impecance) drives the  double diode D5. If this diode has a negilibliable dynamic on resistance  each of the two diodes in D5 will alternatively  route (each half cycle of the BFO signal) the AF signal to the 4 dB 50 ohm attenuator (R114 to R116). This means that the mic amp "sees" a load of 50 ohms!  

Corect?

Henning Weddig

DK5LV


Am 06.08.2018 um 16:16 schrieb Dennis Yancey:

Try this link. 
https://ubitx.net/mod-tx-compression/


--
72 and God bless
KD4EPG

Re: Harmonic performance - SSB vs CW

Gordon Gibby <ggibby@...>
 

​great news warren --- now we need a  way to capitalize on what has been learned and re - do the signal paths.....



Gordon




From: BITX20@groups.io <BITX20@groups.io> on behalf of Warren Allgyer <allgyer@...>
Sent: Monday, August 6, 2018 2:39 PM
To: BITX20@groups.io
Subject: Re: [BITX20] Harmonic performance - SSB vs CW
 

I removed the 80 meter toroids and assembled them, along with the requisite SMD 1000 pF caps on the underside, in line of perf board.  I cut the RF trace from T11 to the relays and routed it out to the new filter via teflon coax.

The 3rd harmonic of the 80 meter CW signal is marginal but would pass FCC scrutiny at -46 dBc. Higher order harmonics are obliterated.

Remember this is CW on 80 meters, far and away worst case. This filter is fine. It is a layout issue.

WA8TOD

Re: Harmonic performance - SSB vs CW

Kees T
 

Allison,

Since you have your uBITX apart, have you checked the individual values of the parts to see if they are to spec ?  The schematic says the low Band LPF should be three 900nH inductors and 1nF, 2nF, 2nF, 1nF capacitors.

73 Kees K5BCQ

Re: Harmonic performance - SSB vs CW

MadRadioModder
 

I’m not suggesting it, I’ve done it.  With a good outboard LPF set, it works and can be compliant with the right set of filters.

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of ajparent1/KB1GMX
Sent: Monday, August 6, 2018 11:11 AM
To: BITX20@groups.io
Subject: Re: [BITX20] Harmonic performance - SSB vs CW

 

Madradiomodeler,

Would not have suggested it if it wan't minimally tested first.

I have a set of Low pass and band pass filters in pomona boxes
with SMA connectors.  Very handy.

If one rips out L1-4 plus the associated caps and uses decent
7 element low pass for the same band groups as the existing f
ilters and a band pass for 10M (4 filters) the result going to
the amp nets a 35db minimum improvement in the raw amp
output.  Not quite good enough to go live without low pass
filters but significantly better.

Allison


Virus-free. www.avg.com

--

…_. _._