Bert Modderman Engineer

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I sell circulators for all frequencies.
70cm to 6cm all bands in stock.
drop in types and with connectors and build in resistor on the 3rd port.
circulators make sure that the amplifier always sees 50ohm.
if you have a bad swr or a broken connector then the reflected power goes into the 3rd port of the circulator.
isolation is 20db or more and insertion loss about 0.25db.
types with 3 connectors are called circulators.
types with 2 connectors and an internal resistor are called isolators.
drop in types need to be put into a recess, that basicly means you cannot use dropin types
unless you have a milling machine or if you know exactly what you are doing. all rf rules have to be followed.
isolators usualy dont come with the power resistor they are rated for.
for instance the 70cm 100w has a resistor of 20w. this keeps the circulator small and cheaper.
and so a cheap 20w circulator is made.
but picture this, you expect only antenna problems with cable of 1.5 db loss.
this means a reflected signal needs to travel to the antenna and back to the amplifier.
that totals to 3db loss for the reflected. a 40 watt transmitter will have a maximum of 20 watt
reflected true a 1.5 db loss coaxcable.

isolators with connectors that i have in stock or that i am trying to keep in stock:
70cm : 200w forward 100w reflected sma or N connectors 80 euro
23cm : 200w forward 100w reflected sma or N connectors 80 euro
23cm: 400w forward 250w reflected female or Male N input, female N output 135 euro
13cm: 100w forward 20w reflected sma or N connectors 80 euro
13cm: 200 watt forward 100 watt reflected N or sma connectors 100 euro
drop in types are 50 euro for 200 watt circulators from 23cm to 10ghz.

circulators for 144mhz are quiet expensive, above 200 euro.
same for waveguide versions of 10ghz and 24ghz, probably more then 200 euro.
i add this here because i have been asked about them. i dont have them in stock and dont plan to. to expensive.

picture of all sorts of circulators