Re: Harmonic performance - SSB vs CW
Kees,
Mica is good but not at all cheap and somewhat scarce and big
For SMT MLC are good fairly cheap too (at the 5000 piece level).
For the rich ATC 100B or of the other series in that desired size
like 600C or F.
Also using T30 size is a bit small for 10W and up.
Allison
|
Re: Harmonic performance - SSB vs CW
More to see if it's possible rather than anything else, I was working on a PCB that would fit in same space as the original LPF area, but switching on both ends of each filter. (ie 3 more relays)? I didn't alter the actual switching sequence just added the extra relays controlled in the same manner as the original ones. Picture is of the PCB. No switching transistors are on the PCB, yet.? You can see space either side though. This is not all routed as you can see, just the RF paths in and out of the relays. (The inductors are shown with 4 holes, just because i? had that part in my LIB.) Orientations may change. glenn vk3pe 
|
Re: Humble suggestion future Ubitx versions
#ubitx
Who¡¯s complaining? ?Yes it is a kit, much like the 10/11 meter mods in the past ¡°cut the green wire¡±.?? It is a kit that anyone can buy, ?and with a little help can operate 1-30 MHZ.? ?I¡¯m an NRA member and see the same thing, ¡° buy this
gun, move this screw¡± and it will do this.
But that¡¯s just me, been a ham for 52 years seen a lot.
K6KWQ
?
Sent from for Windows 10
?
toggle quoted message
Show quoted text
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....
|
Re: Raduino Clone kit from W0EB-N5IB
#ubitx
Gary, my understanding is that the I2C bus is only open drain when reading back the "ACK"? 9th bit on the data line. I may well be wrong here.? Bit banging implementations for I2C will not all be open drain either.
Philips publish an Ap note on using logic level translation on the I2C bus when different voltage levels are used. They use FET's and pullups as no doubt you have seen. Since they invented I2C I assume they know what they are talking about??? In any case, it costs pennies only and is in my view, good practice.
glenn
toggle quoted message
Show quoted text
On Mon, Aug 6, 2018 at 11:13 PM, Gary Anderson wrote:
Glen, concerned about your logic level translator implementation w.r.t. I2C bus.? This is an open drain bus.? Nothing should be actively driven High.? The high state is handled by pull-up resistors.? Pull-up to 3.3V from Si5351 supply.? ?If one part is actively driving HIGH and another part on the bus drives LOW, there is bus contention with high currents on the I/Os which could lead to part destruction.??
Rgds,
Gary
|
Re: Harmonic performance - SSB vs CW
Another aspect of filter design, and to reduce insertion loss, are the capacitors used and their characteristics. In my opinion (and some experience) Mica is the best but expensive,?Polystyrene is second best but difficult to find, Ceramic NPO is third, and I'm sure there are exotic types out there too but they cost too much or are not readily available. You have to watch voltage ratings but not so much in the QRP range.
73 Kees K5BCQ?
|
one 74LS42 with bcd firing from the three output ports assuming they are TTL compatible? and? say 5 BS250s P channel (or four given the number of? relays now available)? say 80 40 20 and 10 mtr? BPF drivers) small signal Mosfets for switch on zero, (or a ULN 2003 (30c US at Futurlec.com in one off qty)..
Say total cost $1.50 could have put a stake thorough this demon...KISS ?? of course it is board space and cost that drives these decisions.
Alternative for physical relays for switching RF up to say 6W level in 50 z impedance circuits...
?a possibly foolish thought for likes of Kees and Ashar F? for any weakware rework concept.. if you fire the gate of a 2N7000 N mosfet? and drive it hard on from an isolated 10V dc supply* with a limiting resistor and a decent say 1mH mini inductor in both the? supply and return legs of the 5V psu - will the thing pass RF as if it were a small signal relay contact ?? RDS fully on for above part approx 1.2 ohms.
* homemade with a Hartley osc design to reduce the snap and crackle.
|
Re: Harmonic performance - SSB vs CW
I¡¯m using this one? https://www.ebay.com/itm/192131587815, but it¡¯s only because I have a 150W amp after the uBITx inside the same box.? It¡¯s smaller than the uBITx though and has a directional coupler on board.? I would think, as others have mentioned, ?Hans¡¯s QRP-Labs modules would work as a good starting place for those looking for a cheap alternative (https://www.qrp-labs.com/lpfkit.html).? They are quite good and $4.60 each band.? I¡¯ve used them a lot..hard to beat.? There are some other QRP radios that have good outboard filter boards that are excellent too¡Kees has some kits that are very well designed.? The one at HFProjects.com is pretty good too¡ ? ? ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of m5fra2 via Groups.Io
Sent: Monday, August 6, 2018 11:39 AM
To: [email protected]
Subject: Re: [BITX20] Harmonic performance - SSB vs CW? Which after-market board is that? I would like to keep any new boards in the same case. ? Colin ¨C M5FRA ? ? ? ? ¡°rip out the filters and the relays and even the TR relay (KT1-3 and K3) and route everything to an external low pass board.?¡° ? Yup, done, works¡ gains almost 30bd in suppression with a good/cheap after-market board. ? From: [email protected] [mailto:[email protected]] On Behalf Of ajparent1/KB1GMX
Sent: Monday, August 6, 2018 9:52 AM
To: [email protected]
Subject: Re: [BITX20] Harmonic performance - SSB vs CW ? Warren,
Not so much disagree as wow! that's terrible... can't be!? Yes, its horrific.
5 images.
NF1 is RX mode with no filters (default is 30mhz) selected and RF applied at RX amp output
and measured at antenna connector.? It is really bad!
F3.5 is TX mode, 3.5mhz filter selected.? The blow by limits us to barely 25DB at 30mhz.
F70 is tx mode, 7mhz filter selected.? Blow by limits us to maybe 25db.
F21 is tx with 21mhz filter selected. blow by limits us to about 30db at 30mhz, not impressive.
F300 is TX with last filter 30mhz, span extened to 50mhz so we can see it.? at 45mhz we
are barely 30db down.
Results, we can argue magnitude but over all the filters are unacceptable in situ.
The first one (NF1) was the one that caught my eye as its pure blow by as there is no
direct path its all random coupling.? That has to be much better before we even
consider filters.
At this point I'd rip out the filters and the relays and even the TR relay (KT1-3 and K3)
and route everything to an external low pass board.? At that point I think we have a chance
with the external board performance being unknown but for certain cannot be worse.
--
¡_. _._
-- ¡_. _._
|
Re: Harmonic performance - SSB vs CW
Warren,
Pin diodes have a lot going for them.? I like them.
What I have to try is two of the filters from the board and using the
poor mans?pin?the 1n4007 diode in pairs two on each side back to back.? ?
Worth a try and what is the cost if it fails.... not much. For two filters?
and 8 diodes its maybe 20cents in parts.
I've used that to 5W for TR switching with good result.
Allison
|
Re: Harmonic performance - SSB vs CW
Since we're all using W3NQN's LPF design/layout from the 1999 QST (Hans, Farhan, me too). Typically 3 inductors, capacitive input/output, etc. The only difference I see is that my designs use a capacitor across L2 Unless someone has already looked into that, I'll? fire up "Elsie" and see what it shows.
73 Kees K5BCQ
|
Re: Harmonic performance - SSB vs CW
I¡¯m considering some BAP64¡¯s for switching tiny bandpass filters in and out in the uBITx right now.? Elecraft nailed this concept in their K3S design, using them everywhere from the front end almost up to the audio stage for switching things in and out¡ ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Warren Allgyer
Sent: Monday, August 6, 2018 4:38 PM
To: [email protected]
Subject: Re: [BITX20] Harmonic performance - SSB vs CW ? 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
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
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 for Windows 10
?
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.
NAQCC 3123, SKCC 4628
|
Re: Harmonic performance - SSB vs CW
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
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
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
Joe
Did you see any difference between the Enhanced and the basic? Was wondering which one to buy?
Thank you
Eric
KC3GDV
|
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
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
?
|
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
|
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
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?
|
MadRadioModder
AA9GG