• Get involved.
    We want your input!
    Apply for Membership and join the conversations about everything related to broadcasting.

    After we receive your registration, a moderator will review it. After your registration is approved, you will be permitted to post.
    If you use a disposable or false email address, your registration will be rejected.

    After your membership is approved, please take a minute to tell us a little bit about yourself.
    https://www.radiodiscussions.com/forums/introduce-yourself.1088/

    Thanks in advance and have fun!
    RadioDiscussions Administrators

Idaho 580 KIDO testing from the 670 KBOI Diplex.

Wow! That's only 90 kHz apart in diplexing terms. Of course from a wavelength standpoint it's about 60 meters. Does that large difference in terms of wavelength help the compatibility situation?
 
I've built diplexed systems. The closest I got was one at 570 kHz and the other at 805 kHz. It was easy to tune the ATU for each quite broadly and to have similarly broad rejection networks. I don't think I could have done one that is 90 kHz apart without a lot of computer assistance.

Even then, we wound our own coils, but were subject to standard values on vacuum capacitors. It was less than the precision the Boise stations need!
 
DavidEduardo said:
I've built diplexed systems. The closest I got was one at 570 kHz and the other at 805 kHz. It was easy to tune the ATU for each quite broadly and to have similarly broad rejection networks. I don't think I could have done one that is 90 kHz apart without a lot of computer assistance.

Even then, we wound our own coils, but were subject to standard values on vacuum capacitors. It was less than the precision the Boise stations need!
Click to expand...
I recently learned that KSFO and KFRC used to diplex! How was that possible?
 
All the filters are in for 670 KBOI (and 580 so they don't have any noticeable effect on 670) and working very good.
Day & night bandpass are very good and VSWR is excellent.

1749182026369.png
 
580 KIDO is still not able to run 20 kw from the diplex. Not sure what power they're running. Issues with filters.
670 KBOI has a notch - 5 KHz in the NDA bandpass that is causing issues.
 
What was the solution?
 
20KW should get out way better now during winter days. Heard them quite well on the Stevensville MT SDR earlier today, in full daylight. 225 miles.
 


Back
Top Bottom