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Remembering my assembly of the QMX that contrast pot was VERY touchy. I went through that panic of black boxes to blank green screen to find a very narrow setting near the right-hand stop that

Yes.

Hi Yuri. I think this is the best overall method of field powering the 50w PA that I’ve seen. For all the reasons you gave like same battery pack and charger for all applications, no DC-DC

After sleeping on this and reading the many fine thoughts and suggestions here, I've decided to try the simplest route:? electrical isolation of the clock output (I only need Clock 0) by way of a

I posted earlier of loss of receive on 80 to 40 m bands after a loud qrn crash. Rx on 30 and 20m still perfect and transmit ok on all bands. Probing pins on IC402 the BPF MUX chip, pin 13, Y3 was no

The problem is likely in LPF2. I've seen a direct trade off on that LPF between 17 and 15m. Try squeezing or spreading the windings, and see what happens to power output. On 2 QDXs I've built, doing

If I see it right the SB-313 needs HFO frequencies from something like 12.4 MHz to 30.2 MHz. I would not run them simultaneously and then select one of them. In the case of square signals there would

Keep in mind that these cables don't generate the 12V, but rather tell the USB-C Power Delivery source (i.e., power bank) to deliver 12V instead of the usual 5V. But strictly speaking, 12V is not one

I am working on the assumption the poor receive performance is because the signals are being drowned out by some internal noise, which due to fault is being fed in the rx path. What is the S meter

Hello, friends Let me share my experience with powering QRPLabs PA50 20m band during field activity. As you might know, PA50 requires about 20V for outputting around 50W. On 20 meters bends it

As already suggested you can get 3 frequencies at a time by using the memory banks on the Progrock 2. This can be combined with a 4 to 1 Mux 74cbt3253 to give one output selected by the BANK select

A couple of options spring to mind, Combine the outputs via small diodes like BAT86. A second option is to combine two multiplexer chips Like 74cbt3253 as a 1 to four mux with a 1 to 4 mux on 3 of the

John, Have you adjusted the LCD contrast preset potentiometer? 73 -- David Thomas M0OOR

Hi, This week i finished the building of my QDX high band. The QDX works fine on all bands. I made some QSO's on 10meter with this QDX. When I measure the transmit power there is something strange

Ah yes, I was forgetting we are not feeding a digital receiver. I do not know if the SB-313 will like square waves. Harmonics might not matter, lots of filtering in these old sets. But maybe the relay

Thanks for the responses, that's excellent news. Mine should be here today, I'll test it with the multimeter first to be sure, I have a mag loop ready to go and I'm especially interested in the higher

In completely digital logic I am using the NOR gates to do a simple 2 input to 1 output mux. I am using it for switching 10MHz signals. The MS5351 is a digital/analog device with 50 Ohm outputs and

I have been using 3 of these 3.7 volt LI batteries = 11.1 volts with my QMX and QDX with no problem https://www.amazon.com/gp/aw/d/B0CSW4LNSQ/ OK you get 4, but I didn't see any quick 3 packs with

After hearing of the damage done to 5351s by connecting the outputs it seems sensible to use buffers. I've not checked but surely there is a way to use one chip which will take the active input from

Hi Ludwig Your reply inspired me to make the gate measurements - The first 4 meaurements were with the FET's in circuit but for comparison I removed Q504 and Q506 and remeasured them.? The 1.8 MHz