Pages: 1 [2]   Go Down

Author Topic: 2m VHF Duplexer for portable repeater  (Read 2498 times)

WB0DZX

  • Member
  • Posts: 40
RE: 2m VHF Duplexer for portable repeater
« Reply #15 on: December 15, 2018, 11:36:25 PM »

Clarification concerning my above comments:

Another consideration would be to forego a repeater - instead using a net control on top. That person would relay when any mobile-to-mobile direct communications is not reliable.
 
Regardless: Any equipment on top should be located to achieve the most radio line of sight. This entails it being on the rim opposite where most of the activity takes place below. It would further help if the equipment were placed on the rim where it "juts" into the canyon the most where the (most of the) course is. If you elect shadowing the participants from above, if possible, that should be done from rim opposite (most of) the activity.
 
If the river is patroled, contact that agency and/or the search and rescue entity to ask how they get communications out of the canyon. Your event should probably coordinate with them anyway.
 
Mike WB0DZX
Logged

WB5ITT

  • Member
  • Posts: 111
Re: 2m VHF Duplexer for portable repeater
« Reply #16 on: November 25, 2019, 12:20:23 PM »

Just stumbled across this topic.. Circuit Board Specialists in CO made a PC Board duplexer that was compact, lightweight and portable and WORKED at 600kHz split...I had one...2db insertion loss per side but it was acceptable.
ARRL should have the article on their web site (it was a late 70s issue but cannot recall exact)...Unfortunately, CBS closed their door years ago...I would HIGHLY suggest silver plating the inside...We used "fixin solution" we got from a photo studio...merely rubbed the solution on the copper using a soaked pad to plate it. I wouldnt recommend it for permanent use in a NON controlled environment. It DID drift but we improved it using better piston caps on the notch tuning.
Logged

KG4RUL

  • Posts: 3781
    • HomeURL
Re: 2m VHF Duplexer for portable repeater
« Reply #17 on: November 26, 2019, 04:34:40 AM »

Just stumbled across this topic.. Circuit Board Specialists in CO made a PC Board duplexer that was compact, lightweight and portable and WORKED at 600kHz split...I had one...2db insertion loss per side but it was acceptable.
ARRL should have the article on their web site (it was a late 70s issue but cannot recall exact)...Unfortunately, CBS closed their door years ago...I would HIGHLY suggest silver plating the inside...We used "fixin solution" we got from a photo studio...merely rubbed the solution on the copper using a soaked pad to plate it. I wouldnt recommend it for permanent use in a NON controlled environment. It DID drift but we improved it using better piston caps on the notch tuning.

QST April 1979 - You will need an ARRL membership to download the article
Logged

KB8VUL

  • Member
  • Posts: 654
Re: 2m VHF Duplexer for portable repeater
« Reply #18 on: November 29, 2019, 04:38:33 PM »

If you are dead set on a repeater and don't have the ability to gather up a set of proper cans for it, you have one other choice.
That being a store and forward repeater.  That would be where the receiver would record the audio being transmitted and once the COR dropped it would key the transmitter and replay the recording.

Obviously there is a delay and there are some other issues to address with it's use, but it's a usable system and doesn't require the duplexer because one radio will act as both the receiver and the transmitter.
Logged
Pages: 1 [2]   Go Up