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Hi Hans, Feedback from a CMOS gate output to its input will result in oscillation at some frequency unique to each chip. It’s impossible to predict the oscillation frequency but in general, yes, it

Has anyone tried using a GPS antenna as used on the Traquito just on leg of 1" that works very well on a U4B? Tom

Adam, You may be chasing a red herring.? In many older or even current inexpensive digital oscilloscopes, if you view the waveform at a much lower rate than its true value, you can see all sorts of

Hans Summers via groups.io <hans.summers@...> wrote: I do. The scope shows some overshoots, but probably the probe needs to be calibrated. Yes -- posted below. Don't be sorry -- in

Some lightweight pole 5-6m or taler depending on the antenna you will be using. There are some nice packable solutions that are less then 0.5m in lenght when folded.

Or simply read a good article in 30 minutes instead of loosing time watching 3 hours of videos, same ammount of info and no forced ads.

Consider looking closely at your 50w amplifier input SWR.? It may stress your QMX PA.? There are ways to address it.? I've written here about using the 50w amplifier multi-banded but I went a fully

Len via groups.io <kc3pwb@...> wrote: Here's what I'm using: 4x 18650 + linear 12V regulator. PAC-12 / JPC-12 with a longer radiating element (5.6 m). If you don't want to

Just to close off this thread, following Jeff Moore's WiKi page I injected a signal of 10mV and looked at the output of the 4 Op Amps and saw the expected approximate 12kHz signal at 10 times the

Many thanks Bojan for the information. Good to hear it works fine. I would like to make the QMX with PA ?my second station besides my IC7300. The main reason is the full break in, i really like

Many thanks Adam for the information. 73 hanz

Here's what I would recommend assuming you're doing CW with the QMX: Battery: This is all pretty low power so you can get away with as little as 3AH of power which will get you more than a couple

Len - a PD capable powerbank 20,000 mAh will provide 36 hours of listening time. Less time if you are the object of a pile-up. I do like my EFHW antennas, but it's a bit of work to get them high in

Stan, thanks for your impressions. I will check voltages on Q110 and Q111 also on Q101 and Q102. Osvaldo LU3MAM [email protected]>) escribió:

Hi Tony > The 833 Hz is low-frequency oscillation, likely being generated in IC202. It's a quite common technique to effectively DC bias the gate's input at almost exactly the midpoint between it's 0

Hi Adam Downstream of IC202 there isn't any "almost", this is the very reason why IC202 is there. You will have a 3.3Vpp output at IC202 output. Can you take a similar video please for the signal at

Ian, So I wouldnt need bpf for each band. Unless of course I needed to filter out other radios TXing in the shack. -- regards, Bryan, N0LUF

Something is wrong with your 3.3V input regulator circuit.? Inspect carefully for solder blobs or shorts, near the connector pins you soldered or anywhere else - it should not operate this way.?

I can tackle this but remember, YMMV. 1. I am using battery packs purchased on Amazon.? I have "AA" packs, 8 cells for 12v and 6 cells for 9v.? I am using rechargeable lithium 1.5v cells.?

Adam, The 833 Hz is low-frequency oscillation, likely being generated in IC202. R207 (470K) is providing a DC bias at the input of the gate which can cause the gate to operate in its linear region,