Yes, perhaps I'm being a little hard on the official agencies. They do their official duties well, are dedicated and fortunately (hopefully) have modern communication systems that will let do their wo

I suppose this has some relevance here, as some people here are getting groups of hams set up with uBitx radios to form emergency communication networks. So lets look at this from the myopic perspecti

Hi, If you don't need all those audio buffer stages and are OK with the audio output to the speaker, maybe something like this chip to directly replace the volume control pot of the uBitx. https://www

Hi, In my case I hooked the microphone input of the USB sound adaptor to the high side of the uBitx volume control. That way I don't need to readjust the volume control to get the level correct if I u

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Good point. I guess that depends on how much you are willing to trade off in transmit power wasted in the series resistor to the diodes. However, the other T/R switches, in the various linked articles

The spice simulation I was interested in, because it was so basic, was schematic Figure 12 and graph Figure 13. I created a schematic in Eagle and ran the simulation last night and was able to see the

A quick look at this article looks very good. I'm in the process of learning the Eagle Schematic capture and PCB design package. That package includes Ngspice. I can use the LTSpice schematic included

Hi, That Wes Hayward article is pretty good. I'd recommend people read it, including myself. I think at the time I found that article we were trying to figure out just how much like a PIN diode the 1N

I can imagine what that was like. I did not work in the space race, but, as a kid, a friends father worked for Autonetics and he would bring us to their employee open house events and we would get to

That is an interesting circuit. So it looks like the series resonate circuit is a low impedance at 40 meters passing the received RF to the receiver amplifiers. Then, when the transmitter is keyed up

Cool site. Fun to look once again, in the context of the era of Heathkit kits and the early space race technology, the electronic designs I poured over learning electronics design. Then think of now,

Hi, I found some reviews of the bitx20a. Did not find a schematic, yet. However, I found this CW transceiver designed by Dan Tayloe that has a couple of mosfets to cut off the RF to the receiver secti

Interesting, I was looking around at sites that featured old Heathkit photos and product information. Found this link. Looks like someone is reviving Heathkit in Santa Cruz California. Maybe a nostalg

Brings back memory's of when I was first interested in Ham radio. The description of that radio/transmitter with dual conversion and crystal filters was something that made me want that rig. I did not

Hi, Here is a thread where the person powered the whole uBitx from 15 volts and raised the output power substantially. This was an earlier revision, so should re-evaluate if any components on the new

Thanks for the URL to the library. Now I can look to see what they did to handle the registers. It sounds like the registers are pseudo registers, not using up I2C addresses. Tom, wb6b

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It looked like they keep a counter in the PIC chip that is on each board, so each time you check the status of an encoder board it will tell you how many encoder pulses took place since the last time

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It looked like they mapped 256 I2C address to the various internal registers and the EEPROM. Then had an additional 7 bits of high order I2C addresses. There is an expanded I2C addressing scheme, grea

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Very clever deign. Also did not know encoders with an RGB LED that could send light down a clear shaft to the knob were available. These boards seem to use a lot of I2C addresses, but they claim they

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That is a clever name. Also: You could try one of the end-fed non-resonate antenna designs with a 9 to 1 unun. Depending on the bands you want to work you can use a 55 or 40 foot wire. The coax is int

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