How to make use of that expensive analyzer you just
bought
Effective RF Suppressors
100nh moulded inductor
1 uh moulded inductor
43 Material Ferrite bead2643250402 (3 turns)
Laird Ferrite Core28b0375000 (2 turns)
Laird Ferrite Core28b0375000 (3 turns)
Laird Ferrite Core28b0375000 (4 turns)
Laird Ferrite Core28b0375-300 (4 turns)
Laird Ferrite Core28b0562-100 (2 turns)
Laird Ferrite Core28b0562-100 (4 turns)
Antenna Relays
These are great relays to use if you have the budget for them
OK but I like to save $. I want to use one of these relays
Receive configuration
RCV (normally closed)
Xmit (normally open)
Antenna (common)
Transmit configuration
RCV (normally closed)
Xmit (normally open)
Antenna (common)
Return loss (SWR)
Compensation for VSWR(2 meters and below)
RCV (normally closed)
Xmit (normally open)
Antenna (common)
5pf mica1kv
5pf mica1kv
Return loss (SWR)
VSWR (return loss) is another problem that gets worse as the frequency increases
•Uncompensated
•5pf added across NO and NC contacts
•Common port terminated in 50z
•Common port open
One of the biggest issues with these relays at VHF is isolation
The highest useful band appears to be 6 meters
Isolation
Compensation for poor isolation
RCV (normally closed)
Xmit (normally open)
Antenna (common)
5pf mica1kv
5pf mica1kv
650 nh
Resonant at 2m
Compensation
Compensation allows us to use this relay at 2 meters
•Isolation (uncompensated)
•Isolation (compensated with 650 nh)
•Return loss (compensated with 5pf shunt)