That’s it, an old PLL came from 90’s! If you search this you can find several versions working or not with errors, mistakes even bad hex files. This is an upgraded SMD version of the original prototype, most of all the electrolytic capacitors have been replaced with SMD Tantalium type, all the other capacitors are C0G type, finally all the resistors are SMD 1% tolerance 1/2W. Regarding output filter part a few critical changes were made, without any changes the output power increased dramatically starting about 24dBm (251.2mW) from 87Mhz ending to 21.5dBm (141.3mW) up to 108Mhz. After changes were made the power at the lower frequency of 87Mhz was 24.20dBm (263.0mW) at 97.5Mhz 24.02dBm (252.3mW) and up to 108Mhz 23.24dBm (210.9mW). Measurements of total harmonic distortion were accepted THD about 0.28@97.5Mhz, -62.23@195Mhz, -63.21dBm@292.5Mhz, -62.59@390Mhz etc…

The quality of sound is quite enough but the audio level is lower than expected. Tested with MPX signal the quality is accectable.

More Measurements And Ideas…Coming Soon…Please Stay Tuned!

Best Regards AkisT

Tagged with:

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.