Then I stumbled on this one (see attached pdf) MT3608 that runs at 1.2MHz and will have

3.6/7.2 blips. Tweak it to 1.15 Mhz and this can be avoided.

Raj

On 10/08/2022 6:47 PM, Ashhar Farhan wrote:

Neils,

Many of these switching regulators have a 50 KHz switching frequency. This has images inside the passband of the audio codec.

I arrived at LM338 only after experimenting with various switching systems (including building one from discrete components). These new generation of switchers move the frequency to 500 KHz. That's what makes them useful.

- f

On Wed, Aug 10, 2022, 6:27 PM John Terrell <N6LN@...> wrote:

The smallest ones have a small cheap potentiometer which I would not trust in the long run to maintain a stable output voltage. Some have a secondary means of choosing between four or five fixed voltage levels and bypassing the fickle potentiometer by cutting a pcb trace with a hobby knife. Loupes help. But in any case a buffer capacitor ought to reduce a noisy output p.

Neils,

Many of these switching regulators have a 50 KHz switching frequency. This has images inside the passband of the audio codec.

I arrived at LM338 only after experimenting with various switching systems (including building one from discrete components). These new generation of switchers move the frequency to 500 KHz. That's what makes them useful.

- f

On Wed, Aug 10, 2022, 6:27 PM John Terrell <N6LN@...> wrote:

The smallest ones have a small cheap potentiometer which I would not trust in the long run to maintain a stable output voltage. Some have a secondary means of choosing between four or five fixed voltage levels and bypassing the fickle potentiometer by cutting a pcb trace with a hobby knife. Loupes help. But in any case a buffer capacitor ought to reduce a noisy output p.

On Aug 9, 2022, at 6:35 PM, Michael <kg5umh@...> wrote:

?Sorry for activating an old thread - every thread regarding this topic seems to lead back to the Ubits Hacks pages.
Still trying to figure out this Amp activation. The amp I intend to use has a simple "short to ground" trigger circuit. I started using this information:?? But I get stopped at connecting the anode of one diode to the orange wire going to the raduino. The v6 board does not have the orange wire. Would the anode of the diode go to pin #2 of the Arduino connector? Pin #2 is the same trace that the ring of the mic jack goes to. Seems that it needs to land somewhere else. I understand the remainder of the circuit, it is the "orange" wire that is causing the confusion.?
--

KG5UMH
Michael - DM93am

Sorry for activating an old thread - every thread regarding this topic seems to lead back to the Ubits Hacks pages.
Still trying to figure out this Amp activation. The amp I intend to use has a simple "short to ground" trigger circuit. I started using this information: But I get stopped at connecting the anode of one diode to the orange wire going to the raduino. The v6 board does not have the orange wire. Would the anode of the diode go to pin #2 of the Arduino connector? Pin #2 is the same trace that the ring of the mic jack goes to. Seems that it needs to land somewhere else. I understand the remainder of the circuit, it is the "orange" wire that is causing the confusion.
--

KG5UMH
Michael - DM93am

On Aug 9, 2022, at 20:56, Lou KI5FTY <lscalpati@...> wrote:

?

Hi is anyone having troubles replying to CQ in FT8 mode.? As you can see in the attached image, when I select a CQ station to reply to, it does not pickup?the call or mycall.? It just transmits nothing, just a single tone.? It was working before I updated to the new version which included ft8 changes.? I click on the CQ line and then hit enter.? Yes I have set it to ft8mode semi.? BUT it does send properly if I switch to the macro keyboard and press F1 - Call button.? Thoughts?

73

Lou KI5FTY