Re: Follow-up Antuino question
|
bob,? i have used it as a local oscillator. but there is a catch The primary purpose of the RF out was to be able to measure the frequency response by feeding?the RF out into the device/circuit under test and measuring the output through the RF-In jack. Hence, the RF output is low, about -20 dbm. This is insufficient?to drive a mixer. There are two ways to fix this 1. You can remove the three attenuator resistors from the RF out pad and directly get about?+10 dbm from the RF out jack. This can damage?the RF In if fed directly. You can build an outboard attenuator for similar to the original RF out attenuator, but remember to use it each time you are testing a device. 2. You can build a two-stage Feedback amplifier with about 16 db gain in each stage with a 6 db attenuator pad between the two stages to provide a useful block of 26 db gain. This circuit will be useful in many other places as well. Use this to boost the RF output to the level needed by the mixer.
- f?
On Sat, Nov 14, 2020 at 8:58 AM Bob Lunsford via <nocrud222= [email protected]> wrote: After rereading the specifications for the Antuino and its oscillator stability, I suddenly wondered if the
oscillator can be used for the oscillator in a Direct Conversion
receiver... Perhaps there is a way to set it up that the antenna jack can be the source for the oscillator signal.
The Antuino has a digital readout and this promises
(theoretically) to be a shortcut and result in an excellent signal
oscillator for a DC receiver. A mixer and an LM-386 audio amp and the
receiver would be simplified and made much superior to an LC
controlled oscillator plus make it usable for a full range of
frequencies. Has anyone considered doing this?
Bob ¡ª KK5R
|
