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If the load is of high enough impedance, you might get by without the push-pull pair. So I might try first without Q72,Q73, drive your tube rig over a twisted wire pair (or coax) from the junction

Jerry I like the idea of the ubitx audio stage. I should have all the parts on hand to give that a try. Thanks! 73 Don ve3ids [email protected]> wrote:

I like the notion of two 74ACT04 gates in push pull. But wonder what kind of trouble you could get into using that to drive a transformer. Whenever I see a full description of the design process for a

It is sobering to think how they got by with such simple gear in say, the late 1920's. Amazing that a single tube regenerative receiver works at all, let alone well enough to use on the ham bands. A

It would work fine. I used my K2 as a VFO for a Drake 2NT until I could get something built for it. We might overthink things in the digital age. They used to be a lot simpler, and the still could be.

Something to keep in mind in circuits that use multiple power supplies is power sequencing: It is important that the 5V comes on before the 3.3V and turns off after the 3.3V when the 3.3V turns off.

Hi all Loading an Si5351A output at 50-ohms also affects phase noise. I did a study of Si5351A phase noise, particularly in relation to the QCX CW transceiver http://qrp-labs.com/qcx . One of the

If you read the datasheet, the Si5351 claims to have a 50 ohm output. But yes, it is primarily designed to replace cheap 4 pin crystal oscillators. Jerry

Good news: Algebra for designing and biasing bipolar circuits. Not so good news: Partial differential equations for biasing FET circuits, though I’d probably just copy an oscillator circuit rather

It’s a clock generator and was designed to drive a logical load, that is, a CMOS or TTL input, and definitely not a 50 ohm resistance. The first rule in a situation like this is to *read* the data

I’d grab a 40 meter tank circuit from one of the older handbooks for a cheap and cheerful solution. Or a DDS circuit like this

Thanks for all the ideas gents, I need to get some parts from Diz and Rex and start experimenting. Hopefully after Christmas.

That ebay amp can drive 50 ohms with a whopping 10dBm, or 10 milliwatts. That works out to about 0.707 volts RMS on the output, less than your Si5351. It's meant for use in front of a receiver, or

It has a 14mhz crystal, a transistor, a few passive components, a transformer, and then a two inductor output filter. So I'm going with Eric that it plugs into a larger assembly, and say that this

No idea, but given the stacking header and part designations all in the 20's, it looks to be part of an assembly. A daughterboard of some sort. Maybe that'll jog your memory. Eric KE6US

Jerry Thanks for the info. I need about 10 volts. What are your thoughts on this? https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F162854440017 73 Don ve3ids

Hi all, I have gotten back into radio after about a decade. ?Finding my goodies I didn’t complete. ?One kit I found doesn’t have any documentation or any info on the board. ?The crystal is

Maybe this 74ACT04N, $0.50 plus $10 shipping: https://www.mouser.com/ProductDetail/Texas-Instruments/SN74ACT04N?qs=sGAEpiMZZMtYFXwiBRPs03JnqncIqXT7 Ground pin 7 with a very short wire (or just bend

Nick, Ah, I vaguely remember a discussion on the bitx20 forum about using a logic gate. Allison kicked it off with a discussion of crosstalk in the Si5351 outputs when they get loaded down: This

On a related topic, I built a vfo with a nano and a 5351 to replace the vfo in a tube rig but I need more voltage to drive it. It will operate the receiver but is just on the edge for the TX. It will