Schottky diodes anyone? Shipped to you for $1;
https://www.ebay.ca/itm/CB-Receive-...h=item2141a8ab41:g:2sQAAOSwsN9XCzwv:rk:3:pf:0
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Mike Debunks Shottky Diode Receive Mod
- Thread starter KD8HMO
- Start date
Now, Mike also talked about the true reason he had the radio in his shop in the first place. That was due to the 1674 and 2SC2999 swap.
He did point out an excellent analogy of how the RF amp and the 1st IF mixer did their jobs and how they worked. They don't Amplify the signal - one just transfers it to another and it's impedance (transformation - Step Up or Step Down or Coupling Isolation)
So to see a 945 takeout and the 1674 used in its' place kinda reminded me of when someone had asked about the 458 the 945 replaced upgraded from - the area is where the SSB and AM signals are processed after detection.
The 1674 is a low-loss RF Amplifier but for IF use - so to see it replacing an otherwise Analogous Audio part for the sake of it - I think the rest of you should go back and read that thread. Because we focused too much on the 2SC2999 and not enough on the swapped Audio for IF part.
It is my thinking that may get me into trouble here but how I look at this is from the standpoint that they wanted better reproduction from the RF envelope, not necessarily from using a low-speed switching (compared to) Audio Amplifier part. But in looking over all the finer details, we can glean that the performance of the part swap was marginal - but if the circuit had been more idealized, the 1674 may have done a better job of reproduction in fidelity than in signal strength. But that's just me...
He did point out an excellent analogy of how the RF amp and the 1st IF mixer did their jobs and how they worked. They don't Amplify the signal - one just transfers it to another and it's impedance (transformation - Step Up or Step Down or Coupling Isolation)
So to see a 945 takeout and the 1674 used in its' place kinda reminded me of when someone had asked about the 458 the 945 replaced upgraded from - the area is where the SSB and AM signals are processed after detection.
The 1674 is a low-loss RF Amplifier but for IF use - so to see it replacing an otherwise Analogous Audio part for the sake of it - I think the rest of you should go back and read that thread. Because we focused too much on the 2SC2999 and not enough on the swapped Audio for IF part.
It is my thinking that may get me into trouble here but how I look at this is from the standpoint that they wanted better reproduction from the RF envelope, not necessarily from using a low-speed switching (compared to) Audio Amplifier part. But in looking over all the finer details, we can glean that the performance of the part swap was marginal - but if the circuit had been more idealized, the 1674 may have done a better job of reproduction in fidelity than in signal strength. But that's just me...