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Suggested Change for VFO: Additional BandStops #bpf #vfo

Steve Jones KA6PRW
 


First real post to group, but I am currently in midst of setting up VFO/SigGen and realized that I would like to add additional LPFs for higher frequencies (an 11 band VFO?!).

So, my suggestion to Hans is: when you have a moment (rain on your window, sleepless night, etc), that maybe it would be useful to add 5 more 'BandStop' positions for the VFO.  I realize that this can also be accomplished with the Presets, but this sounds like a fairly straight forward change (I know, it never is) and would be a cleaner way to get additional bandwidth on he VFO??

Hopefully this has some merit and I am not way out to lunch!
Steve KA6PRW
California

P.S Love the kits, total respect for the work Hans has done, and hopefully will have my U3S on air shortly as well! 
The discussion group is awesome.

Clive Lorton
 

Hi,

On 30 March 2018 at 01:48, Steve Jones via Groups.Io <stvnjns51@...> wrote:

So, my suggestion to Hans is: when you have a moment (rain on your window, sleepless night, etc), that maybe it would be useful to add 5 more 'BandStop' positions for the VFO.  

​I have the same problem​. My SigGen/VFO is sitting on the bench outputting 10MHz to lock my system but the VFO section as a project is on hold.  I had thought of a separate analog switch to switch the LPFs just for ease of use but.....  if Hans could  add "band stop" positions it would be gratefully received here :-)

73 from Clive G8POC

Hans Summers
 

Steve, Clive

Just to make sure we are all on the same page (as is said). 

We already have 6 "bandstop positions" in the VFO, that control 6 processor pins, which control 6 relays and switch 6 Low Pass Filters if you add the  relay board kit http://qrp-labs.com/ultimatelpf - all of that already exists. 

Are you saying that you want 5 MORE so that you can control 11 relays? And if so, with what spare extra 5 I/O lines? Or you want a way to multiplex two relay boards? 

73 Hans G0UPL

On Fri, Mar 30, 2018 at 1:15 PM, Clive Lorton <clive.g8poc@...> wrote:
Hi,

On 30 March 2018 at 01:48, Steve Jones via Groups.Io <stvnjns51@...> wrote:

So, my suggestion to Hans is: when you have a moment (rain on your window, sleepless night, etc), that maybe it would be useful to add 5 more 'BandStop' positions for the VFO.  

​I have the same problem​. My SigGen/VFO is sitting on the bench outputting 10MHz to lock my system but the VFO section as a project is on hold.  I had thought of a separate analog switch to switch the LPFs just for ease of use but.....  if Hans could  add "band stop" positions it would be gratefully received here :-)

73 from Clive G8POC


Steve Jones KA6PRW
 

Hi Hans!
Yes - Have 6, now I want 11 bands! 
I would like VFO to support current freq range, with addition support for 6m, (4m?), 2m, etc. - 

I am going to try and control 5 additioal relays, for total of 11.  Primary plan is to try to use the auxillary bit to mux/select the LPF relay board, as already 'done/proven' on the U3S, but using the VFO's 'preset' interface.  I  think  it would be cleaner to add 5/6 additional 'band stop' positions to do this control.

My current 'backup plan' would be to swtch LPF boards with an external case mounted selector switch, if primary plan fails!

Experimenting!
Thanks again for burning any brains cells on this!

Steve KA6PRW

Clive Lorton
 



On 30 March 2018 at 11:27, Hans Summers <hans.summers@...> wrote:

Are you saying that you want 5 MORE so that you can control 11 relays? And if so, with what spare extra 5 I/O lines?
Oops sorry Hans point taken. ​
 
Or you want a way to multiplex two relay boards? 

​This is probably beyond me.  If all else fails I'll go with a switch.

Hans, so far I'm really impressed with this kit.  The QLG1 works well inside the old plastic vero case that the VGO/SigGen is housed in. I have plenty of room for filters and a switch. Thank you. 

Many thanks Clive G8POC

Daniel Ekman SA2KNG
 

Basic problem with the request is that it doesn't contain a suggestion on how the hardware should work.
I'ts certainly not impossible, just that it has no simple solution that doesn't have the risk of impeding on other functionality. There ain't too many "spare" pins available. There will be only one firmware, so all accepted features are implemented and then you change some parameter in the menues that selects the behaviour you want.
For example; If you want one more pin for multiplexing (bank a/b) it will probably come from this list: gps data, gps pps, button 1+2, encoder a+b. If you choose one of them, what protects them from getting toasted if someone configures it wrong ?
Another way of doing it would be to steal the first relay and make that multiplex 5x2 relays, add some 10 additional diodes and wiring.
And a quite different way would be to use an external shift register and repurpose the relay pins to go to one or more of these in cascade. This requires another board to be inserted between the qcu and the relay boards as to decocde/drive these.
The next problem is figuring out which one of these will be best for the future and then sticking to it. It needs to be compatible and safe for current and future hardware.

Steve Jones KA6PRW
 

Just to be clear:  The change that I am proposing would 'copy' the current "11 Band LPF" addition that is documented and used on the U3S today (11-band U3).




The U3S scheme uses one of the 'aux' bits to select the LPF relay board.  This bit is multiplexed and there is a circuit already proposed and tested, in the same document, to 'filter' the 'aux' bit for use in this new functionality.

All the 'BandStop' settings, both current and the proposed new 'BandStops', would have to incorporate into the user interface, a way to set the 'aux' bit, like is already done in the presets. I do not think this would be difficult.

I have already implemented the U3S modification, for the 11 band LPF, and it works as suggested in the modification document on the web site. 

As I said in the original request, two other options to make this happen are to simply always use 'Presets' as they already have the 'aux' bit functionality (which is 'kludgy' and fairly labor intensive, or, an alternate, although not so glamorous method, is to use a switch that could be used to select between one LPF relay below say 30MHz and the other above 30 MHz.

I think this is fairly straight forward and basing it on the current U3S 11 band modification, the implementation should be relatively straight forward.

I may be wrong - Hopefully this clears up my original intent.

Steve Jones KA6PRW.



On Tuesday, April 3, 2018, 9:49:18 AM PDT, Daniel Ekman SA2KNG <knegge@...> wrote:


Basic problem with the request is that it doesn't contain a suggestion on how the hardware should work.
I'ts certainly not impossible, just that it has no simple solution that doesn't have the risk of impeding on other functionality. There ain't too many "spare" pins available. There will be only one firmware, so all accepted features are implemented and then you change some parameter in the menues that selects the behaviour you want.
For example; If you want one more pin for multiplexing (bank a/b) it will probably come from this list: gps data, gps pps, button 1+2, encoder a+b. If you choose one of them, what protects them from getting toasted if someone configures it wrong ?
Another way of doing it would be to steal the first relay and make that multiplex 5x2 relays, add some 10 additional diodes and wiring.
And a quite different way would be to use an external shift register and repurpose the relay pins to go to one or more of these in cascade. This requires another board to be inserted between the qcu and the relay boards as to decocde/drive these.
The next problem is figuring out which one of these will be best for the future and then sticking to it. It needs to be compatible and safe for current and future hardware.