Along with several physical changes to, additions thereof, the components and their location RF amp section...
I got flamed for "Reinventing the wheel" all because I stood up for Mike in his efforts to show Germanium diodes performance versus their newer Schottky replacements...people notice, so why not try to bump up the Receiver? Is anyone really going to care?
- I'd love to be the one that says yes this works.
But, that relies on the ears of the beholder. Their original parts are no longer made and the newer parts require support part changes to accommodate their frequency response performance and characteristics.
What one may hear is simply a higher frequency bandwidth the Schottky provides to the Audio Detector.
Is that noise a good thing? I don't know - Germanium offered a "latent" and slow response curve to frequency, as you increased the audio bandwidth the Germanium style Diodes simply rolled-off the high end tonal portion. Older folks notice the "Warm sound" versus the sharper - nearly clickety snapping sounds the audio and the noise it's embedded in, makes when it arrives to the listeners ear.
Others notice the AGC performance - pushes the noise floor down. Yes, it can generate that level or threshold power during detection because of the nature of the beast inside the receiver is trying to keep quiet, while the rest of the worlds own noises come roaring into the 1st Stage. So, yes you can call it a reception improvement.
The issue of this thread is about a Transistor - that can use these performance enhancements and it can and will do circles around most other radio equipment made in the day, for the modes you listen for and use still today. But that is not possible or needed for all radios or equipment - keeping the original design gave you predictable results as the engineers that built it, put in for those designs back in those days.
You may be asking for more trouble in trying to do the upgrade than to keep original design.
No one, except the end user has to bear the burden of proof - after all that effort to Develop, Manufacture and Retail - no one bothers to ask the Customer "How does this sound?"
If you're the Older Guy, you'd say "It's a lot to listen to."
If you're the Younger Guy, you'd say "Give me more!"
I can see why Mike gets annoyed. He was trying to send up a flag.
Now, if you want that clickety sharp sounds of these newer radios - that's fine. But to attempt to retro-back this performance into the older radios requires more than the outcome may be worth. Sure you can fix the RF amp section and do up a card that is a drop-in for the original. Yes, you can make the AGC work better (relative term) - but why?
Only if the receiver needs help. Was it damaged? Then we go back to Robbs' question of the PIN diodes. They may be the biggest problem - because they suffer from the most abuse and damages caused by RF power spikes and noise pulse events that can serious erode the ability of the PIN Diode to stay sharp and work only when needed. They do degrade from impulse events and they tend to lessen the receivers ability to keep listening.
We need to remember that Schottky may cure a symptom, but the problem is still there. MC301's are hard to find.
They instead offer a new external speaker upgrade with tonal filtering to make it sound LIKE YOU ARE LISTENING TO THE ORIGINAL...
Sigh...
