Hi Micheal i watched your vedio's and would like your doing a great job keep up the good work i just put on a 2 meter d-star repeater and now planning on doing a uhf but i would like to know where can you get the software you are using in this vedio for receiver de-sense
thanks mike ke3jp with the KB3WNO D-star repeater in Greenville , Pa
Wowie great setup--got some fine tuning to do then now that you found the problem. Yep i know duplexers are expensive and the extra filter should have worked but try removing the extra filter and see what happens -- just a thought, but maybe you tryed that also. Just trying to elimate things in the lines.
Try the same test while terminating the output of the duplexer into a high quality dummy load. Make sure you use double-shielded cable like RG-400 or a short run of solid shielded cable like a Heliax for the jumper. If the problem goes away, then the problem is in your antenna or feed line. If it doesn't, try the same test running the TX directly into the dummy load. If the problem goes away now, it's in the duplexer or interconnect cables. Good luck & 73! de WD8OCS - Chris
There are too many factors to tak into account what the de sense problem is.
You need at least 80 DB of attenuation from the rx and the tx. AGAIN... too many factors to know where the de sense is coming from. It could be the feed line (not double shield) connectors, duplexer, receiver and if the transmitter is iperating properly. Some xmtrs will go wacky when you go to low power.
CONCLUSION... you have to take the whole system into account and see where the WEAK LINK or poor desing is.
That's not desense, it's wideband noise from the transmitter. You can confirm it by monitoring RSSI or AGC in the receiver. You need to add a notch at the RX frequency into the TX path to stop that noise.
That test was awesome! Great job! I would like to see the same test replacing the repeater antenna with a mag mount mobile antenna to see if you have the same problem? In my opinion it's antenna, feedline or my major suspect is the duplexer. Have you tried the duplexer without the pass cans on receive? 73's Gary K2ACY
Hi Micheal i watched your vedio's and would like your doing a great job keep up the good work i just put on a 2 meter d-star repeater and now planning on doing a uhf but i would like to know where can you get the software you are using in this vedio for receiver de-sense
thanks mike ke3jp with the KB3WNO D-star repeater in Greenville , Pa
ke3jpmike 2 months ago
Micheal I really need to know about the icom tuning software that is in expert mode.
dv6000hp 3 months ago
@dv6000hp I've sent you a message... check your YouTube message box.
michaelcarey 3 months ago
Wowie great setup--got some fine tuning to do then now that you found the problem. Yep i know duplexers are expensive and the extra filter should have worked but try removing the extra filter and see what happens -- just a thought, but maybe you tryed that also. Just trying to elimate things in the lines.
Wish ya luck though
N7JJY Wyoming USA
archuka1 5 months ago
excellent setup!!!
spymsn 7 months ago
Great video's... Hoe do you get into expert mode, with the software
dv6000hp 1 year ago
Did you ever figure out the problem?
dv6000hp 1 year ago
Can You show characteristics of that duplexer?
PanPancerny1986 1 year ago
how about using a two (2) antenna system? Could also be a leak in one of your cables?
DW1PJM 1 year ago
Michael,
Try the same test while terminating the output of the duplexer into a high quality dummy load. Make sure you use double-shielded cable like RG-400 or a short run of solid shielded cable like a Heliax for the jumper. If the problem goes away, then the problem is in your antenna or feed line. If it doesn't, try the same test running the TX directly into the dummy load. If the problem goes away now, it's in the duplexer or interconnect cables. Good luck & 73! de WD8OCS - Chris
cm44126 1 year ago
Hello. Nice video ! What is that software you are running in "expert modus" as you say ?
rdehli 2 years ago
There are too many factors to tak into account what the de sense problem is.
You need at least 80 DB of attenuation from the rx and the tx. AGAIN... too many factors to know where the de sense is coming from. It could be the feed line (not double shield) connectors, duplexer, receiver and if the transmitter is iperating properly. Some xmtrs will go wacky when you go to low power.
CONCLUSION... you have to take the whole system into account and see where the WEAK LINK or poor desing is.
wb6bjm 2 years ago
That's not desense, it's wideband noise from the transmitter. You can confirm it by monitoring RSSI or AGC in the receiver. You need to add a notch at the RX frequency into the TX path to stop that noise.
crustyradios 2 years ago
You need a fair amount of attenuation to stop desensitization. Have you swept the duplexer to ensure it's doing what it's supposed to do?
crustyradios 2 years ago
That test was awesome! Great job! I would like to see the same test replacing the repeater antenna with a mag mount mobile antenna to see if you have the same problem? In my opinion it's antenna, feedline or my major suspect is the duplexer. Have you tried the duplexer without the pass cans on receive? 73's Gary K2ACY
garyp609 2 years ago