1 Duplexer & 2 Frequencies??

[ywhic]

I have a test setup in process for a GMRS repeater..

I have an incoming 50w antenna duplexer/notch filter from HK.

Its going to be pre-tuned for a split of 467.550 RX / 462.550 TX..

Can I use another frequency like 467.575RX/462.575 or maybe 467.625/462.625 on the same??

Do you think the NOTCH would allow the extra 0.025 or 0.075 in frequency to pass??

Be nice to use for 2 channel splits if I wanted to..

 

[popnokick]

If your new duplexer is doing what it is intended to do after being tuned for your primary frequencies, it is not going to let the other channels pass.... even if they are adjacent channels. OTOH, if the duplexer is lower quality and/or not properly tuned then you may be able to get impaired performance on both of the channels you're interested in. I wouldn't think you would want to do that since it opens the door for other problems with adjacent channels rejection, interference, desense, and other undesirable things that a duplexer is designed to prevent.

 

[prcguy]

Even on a high end pass/notch duplexer you can run the adjacent channel with no problem, they are not that sharply tuned. A 6-pack notch only mobile duplexer will pass at least 100KHz of span with no degradation due to its design.
prcguy

 

[ywhic]

Even on a high end pass/notch duplexer you can run the adjacent channel with no problem, they are not that sharply tuned. A 6-pack notch only mobile duplexer will pass at least 100KHz of span with no degradation due to its design.
prcguy

Thanks.. and yes It is the 6 cavity duplexer from EB for $100'ish..

This is what I was hoping to hear.. 0.075 is below the 100khz..

I have these freq's in both Motorola GM300 radios (set at 20w with a CPU fan)..

467.550/462.550 (with PL)
467.625/462.625 (with PL)
467.550/462.550 (no PL)
467.625/462.625 (no PL)

This allows me for open (no PL) or closed (PL) setups..

Anyone else done this with their HK/Ebay duplexer??

 

[WA0CBW]

If I may suggest, why don't you use the same frequency for both? Program the repeater with 2 channels, one with PL and one without but use the same frequency for both.

BB

 

[ywhic]

If the duplexer can't do both I will stick with the one on the label.. (still waiting)..

I do plan on 1 channel with PL and 1 channel without PL..

Just wanted to know if 2 freq's were possible if they are close like thay are..