Hi Jim, A long bunch of yeas back I did an 7x7 L tuner with one switch and two rotary encoders. I'd learned from Altair in early 75 that switch flipping was painful so two 7 bit up down counters drivi

I have a Elecraft T1 and it can and has tune most everything thrown at it including an end fed half wave (maybe 2500 ohms). I've joked it can tune a nail on 80m. Manual for T1 says 10:1 range, less on

IT can and usually is soldering of the T1 coils one or the other. If not then check for other errors. The opamps are not generally fragile so if one got killed there was effort applied. Allison ------

#qcx20mini

general the RX in teh QCX (all versions are identical) is fairly high sensitvity and handily passes the is it working test... That being attach it to a real antenna [my 40M dipole] and does the genera

#alignment

FYI the measurement point for current and voltage is the collector of Q6 and the cold (rf grounded) of L4. You can also measure the radio on RX and subtract that from TX to get a slightly less accurat

Matching is not required. Also do not apply Bipolar device nominal behaviour to MOSFETs. They are really different along several dimensions. They are running as saturated switches. That's why it works

The key elements of class E is saturated switching of the devices and the Phase relationship of the load matching network so that switching happens at the zero voltage point. IF the Keying device is g

From my perspective.... Doing even 6M using QCX as a foundation is not without issues. However doing 2M is wishful thinking and the only way is a transverter as then you keep all the QCX features. The

#mods #vhf #qcx #chat

If I ever did something like that I'd be profuse in my apology and profane in my self condemnation. And even faster trying to delete it. Allison ------------------------------- Please reply on list so

Most likely causes... Bad soldering causing a board level ground issue. Power source (not battery) with filtering issues. Local interference (electronic devices). Allison -----------------------------

#40m #video

Taking a break from antenna and tower mechanical stuff.... I was a winders user all the way through NT4 where I was a MSE. Then M$ phased it out and went win2K, new and different animal. At that point

Charlie, The key thing to remember is remove the heat... if the mosFets are cooking then a bigger heatsink or a fan should be considered. Generally the hardrock and other were designed for intermitten

#50w

I have used it as SSB RX by adjusting the filter high pass to 250hz and the low pass for 2200hz. The stuff needed to calculate that is in the infor for QCX on QRPLabs. As to the I&Q base band phase sh

As I have developed and also built many MOSFET (HEX -irf510 and LDmos MRF and MRFE) amps several things... The amp was purpose designed for the QCX, anything else is experimental and on the experiment

#50w

Lo Radiation even RX (its needed to RX too). This question appear about every 4 months in some form or other. Allison ------------------------------- Please reply on list so we can share. No private e

Depending on the tak the bench surface and a bit of masking tape does it. the work surface is a conductive pad. and under that is a embedded layer of copper screen with a layer of epoxy cost for a har

Short answer is yes but you need 20V. Long answer is its not what your thinking as it only wants 25-35 milliwatts of drive. 3W would fry the input. Also it was designed to part of a radio so ther eis

Tentec used reed relays for many of their radios as they are fast and quiet. Allison ------------------------------- Please reply on list so we can share. No private email, it goes to a bit bucket due

I've used the same filter as in the QCX and its easily shifted and its performance does not change. That assumes the right values used and its band width is easy to change as well. I've done various c

My PS for running the big amp is a pair of 13.8V and a 28V SMPS in series with suitable diodes to prevent reverse voltages. The SMPS used are isolated that being no common path to input side (line) an