[NLRS] Circulator vs Isolator for 902 MHz

[Scott]

Been having a little trouble with the feed on my dish...it seems to be 
intermittent.  It appears that my DEMI 902 transverter does NOT like 
intermittent.  If I key the transverter with no drive and into a bad 
antenna feed (presumably an open), I show something like 5W output from 
the transverter.  So, I put a sampler at the feed connector and take a 
sample of the RF and feed it to the spectrum analyzer.  I see output at 
around 434 MHz, so it appears the PA module is oscillating with a bum 
load attached.  Not unbelievable by any stretch.  Anyways, would an 
isolator (or a circulator with the proper port terminated with a 50 ohm 
load) be a solution to keep it from oscillating?  Unfortunately, my DEMI 
is built with a common RF connector at 902 MHz...seems I would need to 
split into seperate TX and RX lines.  Other ideas (yes, I suppose the 
best thing would be to fix the feed!) ???  I'm just thinking it would be 
good to have some sort of protection against feedline/antenna problems 
out in the field.

-- 
Scott N0EDV