Nick
1. Wired OR diodes used for Relays J1A B? great idea. and I can see you seem to have allowed for relay contacts being opposite sensed. Ie J1A B set is active when Energised and Energised is out of cct.
2 . you have three signals and because of the wired or you have effectively four states without using a decoder. So how is the R5 to be energised. ?? Is it there for case of special software mod plus I2C or ....?

3. You need to define the relay functions.? From a Sota point of view it makes sense that J1AB set is a 20/30m Filter. Ie NO relay energised when working 20m.
then J2 becomes 80 m. then J3 40m? and J4 becomes 15/17 and J5 becomes Ten m after some magic.
4. You have allowed? spike suppression diodes for all relays except first pair. Forgotten or? there is a reason. ??
5. Kees Talen is also talking of a Five relay board design.? With Decoding to be done Off board somehow. Perhaps you need to check up his thoughts.
6. Given? 5.? I would suggest that you allow sufficient pads for a? 74HCT42 decoder and? a 78L05 to power it.? These pads could be on basis of wired chip mounted as SM (legs become feet at 2mm up from tips) so the cost of the holes is not there.? You will also need 4 off BS250 P Mosfets? (simplest solution and they are cheap) to activate the last four relays sets.? The points where the Wire goes off to the Wired OR should be? a through hole rondel.? All this could be squeezed in up T LHS of board as presented without much increase in board space.

The final wiring could be done with? Cat E wiring cores stripped out for those who wanted to go this way . I would suggest the following mapping? 000 as input to decoder? means nothing.? Same for 001.? 010 activates relay set 2 and also energises J1AB via wired OR? .? ...etc all the way to 101. If you use PNP transistors, you will be up for one extra current control resistor per bit.? BS250s are logic level Mosfets? RDS on approx 14R.? Futurlec.com have? them Rockby in Australia list them but have to order them in.?

The mappings and Relay usage have to be defined up front or? the software will be a schmozzle.?

Is the current voltage going to K1 coil 12V .. the schematic calls it Tx voltage. It appears likely to be 12VDC but without details of the guts of the Raduino I cannot be sure.

Just to exclude you weren't listening the WWV. You also can use the other references at 5 and 15Mhz. Usually when I calibrate something as a double check I use these references too and a shortwave broadcast using ssb

ajparent1/KB1GMX schreef op 2018-08-30 20:55:

Another user installed the KD8CEC software and found it to be an
improvement.
Changing the pull up will not help the issue. The factory code is
slow in
recognizing keying.

Okay!
Yes, I bet it takes a while for the code to recognize if we have a keyer input and then switch from USB to CW... Maybe I should hack the code a bit since I want to stick to the stock firmware for a while.

Another approach I see is changing the hardware input. I will investigate both and get back on this topic.

Allison

Regards,
Joop PG4I

Ben Holmes schreef op 2018-08-30 20:17:

This might be a possible fix:

_._,_._,_

Thanks Ben,

will have a look.

Regards,
Joop PG4I

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Probably just the boards, You need to re-use the LPF from the existing board.
Option to add a Firth filter is you want.

Relays are Omron g6s-2 12v

73 Nick VK4PP

More:

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Hi All.
Hows this look:


73 Nick VK4PP

Those points need series inductive(lossy ferrite) and/or resitive isolation as the
caps have ESR and however low if you present RF from the power supply side
its not sufficiently effective.

Of course if the ground via adds resitance it may not help.

Allison

On Thu, Aug 30, 2018 at 02:56 PM, Kees T wrote:
All of the WA2EBY derived dual MOSFET Amp designs I've seen (IRF510, RD16HHF1, RD15HHF1) have a "compensation capacitor" across the output transformer primary.? Used to balance the 3-30MHz range gain. I used one on my 20W Amp kit (and the feedback loop if needed).

I'm familiar with your 20W amp.? Nice work.

The uBITX PA does not have such a capacitor on the schematic .....why ?

Actually the cap does several things but it may or maynot be there.? Most cases its to?
counteract remnant or leakage reactance from the transformer that occurs due to leads
and also coupling less that 1.? ?

In the case of the uBitx the existing transformer is well coupled but has far to much
inductance and any capacitance tended to make it worse at higher frequencies.
the winding is also high resistance.? Add to that the leas are long (full length) and
there are long and many tracks due to layout that are built of narrow traces. With
the circulating currents of @a or more would you use traces that narrow?

The feedback is not RLC but RC and should be RLC to compensate for the reactive
input of all mosfets.

That said if you delivered at least 500mW of power to the gates you get 10W out.
The drivers however do not deliver this above 9-10mhz.? So you get deceasing
output to 10M.? For mine at 10M it was 1.8W out but the drive was a mere .075mW.
Yet we blame the IRF510, looks to me 13db or more gain is not so bad.

The cap does not need to be a 500V part even at 28V as the mosfets will self destruct
at 100V, so a 100V cap is fine so long as it can handle high RF current.

Allison

Today I got the Si5351 running, so all the subsystems (LCD, encoder, Si5351) are now operational. Next step is to try to build stock uBitX code on the new platform.

JC? Keep that Bitx17A .. it seems there will not be many more kits made.

......and the "compensation capacitor", since it's across RF voltages, should be a 500V Mica in the 47pF to 150pF range.

73 Kees K5BCQ?

I worked a station in Antartica from my QTH in Oregon, a distance of 10,455 miles, on a Bitx17A running 8 watts into a EFHW antenna. I have the QSL card to prove it!

Joel
N6ALT

Thanks, Iz Oos!? Just to be sure I'm not missing something subtle, why not just use WWV?? It is AM, isn't it?? And I know for sure that it is on 10.000000 MHz which is more than I can say for AM shortwave broadcasts chosen at random.

--Mike

.....and I would still parallel a 1nF-10nF capacitor across the existing 100nF DC bypass capacitors....including the 2 MOSFET bias voltage bypass capacitors.

73 Kees K5BCQ