Title: 6 Meters
Post by: WD8BXS on 25. March 2020, 13:52:57
What is needed to allow the mcHF on 6 meters.
The new firmware allows it, so how can we use it?
Has anyone tried it?
Chuck |
Title: Re:6 Meters
Post by: DF8OE on 25. March 2020, 14:09:07
Hi Chuck,
you need- a SI570 which reaches 204(208)MHz
- a replacement of the divider with potatoe chip
- mixers (TX/RX) that are fast enough
- a new bandfilter with capability of switching to it
- a lowpass filter with capability of switching to it
- a new designed power amplifier / driver stage
...that's all...
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Title: Re:6 Meters
Post by: SP3OSJ on 25. March 2020, 14:14:32
Hi
That's a good question.
I think about it too.
Andreas how to control BPF and LPF band filters more 4 position (4xLPF and 4xBPF)
What control system (code) is from the BPF and LPF (more 4position)?
Which are the processor pin to control BPF/LPF (for 1,8-50MHz)?
Which "menu" item allows you to configure BPF and LPF control (for 1,8-50MHz)?
73
Artur |
Title: Re:6 Meters
Post by: DF8OE on 25. March 2020, 14:31:29
With mcHF design it is impossible to drive more than 4 different bpf/lpf. There must be another switching hardware and software, e.g. an I2C GPIO (switch).
EDIT:
So 1.8MHz (160m) never was (and will be) covered using existing hardware, too...
In mcHF conception two bits are used for position (that results in 4 positions) and one bit is for toggle pulse for bistable relays.
vy 73
Andreas |
Title: Re:6 Meters
Post by: SP3OSJ on 25. March 2020, 14:43:32
Is another BPF / LPF switching system implemented (no 2bit BCD) in UHSDR ver 2.11.79? If so, how to activate them (I2C)?
Andreas write something more (specification) how it works in firmware 2.11.79 then I will design it, then I will do it and run it.
OK? |
Title: Re:6 Meters
Post by: DF8OE on 25. March 2020, 15:06:05
Actually there is nothing else implemented than mcHF style switching. It will be implemented if development stage of rf part is finished to the point we need it - if we need it. There is a HMC1023 filter configuration implemented (rudimentary - selectable only via debug menu at the moment). I will prefer to use this than switchable bpfs.
vy 73
Andreas |
Title: Re:6 Meters
Post by: SP3OSJ on 25. March 2020, 15:17:36
Andreas, remember that LPF filters are still available.
Therefore, do not use 1.8MHz in mcHF without an additional external LPF filter up to 2MHz |
Title: Re:6 Meters
Post by: DF8OE on 25. March 2020, 15:58:27
Yes Artur - of course.
Using MAX7320 (https://datasheets.maximintegrated.com/en/ds/MAX7320.pdf) you can get 8 lines. Using lines directly for switching you can get 8 filter banks, using binary decoder you can get 256...
vy 73
Andreas |
Title: Re:6 Meters
Post by: SP3OSJ on 25. March 2020, 20:13:55
In mcHF conception two bits are used for position (that results in 4 positions) and one bit is for toggle pulse for bistable relays.
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Maybe yes: two bits are used for position + one bit is for toggle pulse for bistable relay = 3 bits -> (9 positions for monostabile relays -classic layout used in many TRXs)
73
Artur |
Title: Re:6 Meters
Post by: WD8BXS on 26. March 2020, 00:03:02
Since this is an almost impossible task for most, then why have it in the firmware to tease us?
Chuck |
Title: Re:6 Meters
Post by: DF8OE on 26. March 2020, 07:58:45
Because the firmmware is also developed for OVI40 (but kept in compatibility with mcHF). OVI40 will cover all these bands.
vy 73
Andreas |
Title: Re:6 Meters
Post by: SP9BSL on 26. March 2020, 07:59:24
Hi Chuck,
the firmware is intented not only for mcHF, we will add the hardware detection soon and I think limit the available frequency to detected (or default) hardware. Not all is possible for mcHF or its clones.
Artur:
The simple binary selection on 3 bits only looks simple, if we use bistable relays (the official state we have today) we need to change relay coil current direction. You can't do it by one bit as you said. If you have other opinion just draw the complete schematic with relays and explain the idea.
Alternative RF part for OVI 40 UI has aditional latch and demultiplexers to allow more bands.
edit: Overlapped post to Andreas :) |
Title: Re:6 Meters
Post by: SP3OSJ on 26. March 2020, 14:57:22
Hi
I would see it this way:
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Title: Re:6 Meters
Post by: DF8OE on 26. March 2020, 15:10:05
Hi Artur
you need B3 for toggling the bistable relays. Not usable for coding bands.
There is no need for thinking about usage of the three pins. Just use I2C control - it is much more flexible.
vy 73
Andreas |
Title: Re:6 Meters
Post by: SP3OSJ on 26. March 2020, 17:33:57
Title: Re:6 Meters
Post by: DF8OE on 26. March 2020, 18:04:33
Yes - that is possible of course. We can take I2C for band addressing and one of the mcHF bits for toggling relays (bistable ones) for LPF circuit.
vy 73
Andreas |
Title: Re:6 Meters
Post by: SP3OSJ on 26. March 2020, 20:31:25
Andreas, can't you do that in BCD code?
The processor still has free pins:
7, 15, 22, 49, 53, 57, 91, 92, 89, 124, 127, 128, 129, 144.
None of the free pins can be adopted for code 000, 001, 010 ...... |
Title: Re:6 Meters
Post by: DF8OE on 27. March 2020, 06:02:53
I can - but I will not go that way. Too many lines would cross the PCB borders. All of my already designed PCBs are based on I2C and/or SPI control.
vy 73
Andreas |
Title: Re:6 Meters
Post by: SP3OSJ on 27. March 2020, 13:23:56
Andreas, I can wait, but the problem is that I have no faith that the RF TRX OVI40 part will ever be designed.
I'm sorry I wrote it.
But for us to understand each other we have to talk honestly.
If this post is not good, delete it!
73
Artur |
Title: Re:6 Meters
Post by: DF8OE on 27. March 2020, 13:35:06
I know it best: I am working on it.
vy 73
Andreas |
Title: Re:6 Meters
Post by: SP3OSJ on 27. March 2020, 14:19:07
I understand, or my fears are unfounded.
I am very happy about that.
I wish you much health.
I also get to new work:https://www.amateurfunk-sulingen.de/forum/index.php?board=13;action=display;threadid=1528;start=0#lastPost (https://www.amateurfunk-sulingen.de/forum/index.php?board=13;action=display;threadid=1528;start=0#lastPost)
Artur |
Title: Re:6 Meters
Post by: DF8OE on 27. March 2020, 15:33:05
Yes - I have seen. Sorry but I do have very less time so I am not able to work at more than one project. It is a nice PLL board - I haven't read specs about phase noise / jitter onla the main goal: 35...4400MHz...
vy 73
Andreas |
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