¿ªÔÆÌåÓý

ctrl + shift + ? for shortcuts
© 2025 Groups.io

Re: 11. Potentiometer tuning for the Ultimate3


 

¿ªÔÆÌåÓý

Hi Hans,

I have been analysing this problem by setting my U3S to transmit the Analogue input channels 0-4 & 8 using the MESSAGE menu and TX CW mode. An undocumented feature I found is the actual analogue value is briefly shown on the display while it is being transmitted.

Results;

With Tn=0

CH0 = 1023 (Band 1 relay)

CH1 = 1017 (Switch S2)

CH2 =? 925 ¡®Switch S1/TUNE¡¯ pot at max, 511 pot at centre, can¡¯t measure below this as menu runs

CH3 = 1023 (Band 5 relay)

CH4 = 000 (pin 27)

CH8 = wide variation each time (internal temp) but around 290-350.

With Tn=1

CH2 = 556 pot in any position. (Menu run not affected).

?

BTW, ¡®CW¡¯ mode selected just jams the Tx on immediately and the only way out of this is a full RESET.

?

Hope this helps Hans.

?

73 Ken G4APB

?

From: [email protected] [mailto:[email protected]] On Behalf Of KENS 2ND ACC via Groups.Io
Sent: 02 November 2017 08:49
To: [email protected]
Subject: Re: [QRPLabs] 11. Potentiometer tuning for the Ultimate3

?

Hi Hans,

If you get a chance to consider the problems I mentioned earlier, here is some more data;

?

If I disable the Tune pot (Tn=0 in menu), and set the tune pot to anything lower than mid setting, the menu runs through as if switch S1 is pressed.

How do you programme for this conflict, is there a voltage level at which the A-D input on S1 decides whether it is a switch press or a minimum pot setting?

As I said, I measure approx 0.5V on S1 with Tune pot at minimum, and approx 4.5V at max setting, and 2.5V in centre position, so it is seeing less than 2.5V = switch pressed. I would have expected it to see anything above 0.5V as a pot setting only, and below that as a switch press.

?

FYI, I replaced the S2 switch with a combo push-pull switch/linear pot so I can still set the menu up, jam it on tx (ptt) for testing, AND have the tune pot all on the QRP labs case front panel. Was a mechanical nightmare to fit (is bigger than your rotary encoder), but looks good now. After so much effort I am keen to get this working.

73 Ken G4APB.

?

From: [email protected] [mailto:[email protected]] On Behalf Of KENS 2ND ACC via Groups.Io
Sent: 01 November 2017 17:07
To: [email protected]
Subject: [QRPLabs] 11. Potentiometer tuning for the Ultimate3

?

Hi Hans,
I added the U3S section 11. Potentiometer tuning for the Ultimate3?modifications to my v3.12 version but am getting problems. This is a U3S Transceiver using standard U3 Tx with relay switched LPFs and a standard Rx module with Polyphase board and 7MHz BPF fitted.

I have set Tn mode = 1 in the menu.

Problems are;
1) Upward frequency tuning only in Tx WSPR mode. I can hear clicking on my monitor Rx when the Tune pot is turned to min but the frequency does not go lower.
2) In RX mode, upward movement of displayed frequency only, but it does not actually change the LO frequency (using 7mhz band). NO downward frequency either.
3) Loud clicking on Rx audio once pot is away from centre setting (in freq up or down positions)

I measure approx 0.5V on S1 with Tune pot at minimum, and approx 4.5V at max setting, and 2.5V in centre position.
Both S1 and S2 switches functioning ok.

I tried a complete 'RESET' and re-configured all my settings
I have used a 10k linear tune pot with 1k resistors.

Any ideas what may be wrong please.

73 Ken G4APB

Join [email protected] to automatically receive all group messages.