SGQ-450D Duplexer - Tune-up and Review

[LeoG]

Wasn't really talking about testing, but real world conditions.  The conditions between my house and repeater are sort of at the fringe even though it's only 1.9 miles as way of the crow.  And while walking around my neighborhood I can usually reach the repeater and transmit audio through my 5 watt HT.  There are times where I can hit the repeater and get nothing, just a blank receive from the repeater for the whole transmission and then the courtesy tone.  I  have a courtesy tone on my repeater so I know when I hit it with absolute certainty.  But I've never heard what I would consider an oscillation.  This theoretical oscillation would only happen as long as the HT is keyed up.

[marcspaz]

Maybe the word oscillation is whats got me. Oscillation is usually internal to the repeater due to a failure. Or if the separation and isolation are not good, you can end up with a transmit loop if the input and output tone are the same. You won't have any oscillation.

If you have a short tail, the repeater transmit may cut in and out as the receiver cuts in and out. I usually set mine to 2.5 seconds. You will hear the remote station drop out and come back in, but the transmit stays open for 2.5 seconds after the last drop.

[LeoG]

Yep, mine to.  But lots of sites run quick.  But that does answer the question about if there is a delay.  Yes, transmit stays on for predetermined time.  I guess my brain was off when I was thinking about that.  Not the first time, and I"m sure not the last.

[LeoG]

Looks like the duplexer is on the way and should get here late Wed if things go well.

[LeoG]

Did my walk around the block with to have a record of the 2nd original duplexer.  Since I do these things late at night I have a digital recorder I use to "listen" to me.  I do the test of the repeater and then switch to talk around to let me know where I am in case the repeater test doesn't go through.  There are a few spots on my walk that are iffy.  Like I've mentioned in other threads I have 1.6KM of dense forest in the way of my signal, 70' trees with my antenna at 40'.

After the new single channel tuned duplexer is installed I'll try to do the same test in the same spots.