Last summer I posted a YouTube video of a comparison between my IC-7000 and IC-9100. Just listening to some VHF FM chatting going on; I thought I'd see what the difference between the 2 rigs would be - I re-cabled the antenna's to an Alpha Delta switch and was able to switch between them. That's it, pretty simple.
YouTube Video
When I switched between the 2 rigs, I was pleased with the apparent sensitivity of the 9100 compared to the 7000. The night was somewhat quiet and there was very little background noise anyway; but still - the 9100 S-Meter was reading S-5 or so with the 7000 having no S-Meter movement.
The interesting thing is that I received a number of comments/e-mails/suggestions that I turn the 7000's pre-amp ON in order to have a "fair comparison" between the 2 rigs. Adam Farson (AB4OJ) has a FAQ which mentions the S-Meter is calibrated accurately when the Pre-Amp is ON. Page 148 of the 7000 manual states "Sensitivity (at pre-amp ON)" - which I never noticed at all before this event occurred...
Anyway, I suppose I need to give it a try and see what the difference is - I'm also wondering if the 7000 actually has a 2m/70cm pre-amp built in. It's on thing to turn on a setting, but it's another for the setting to do something useful. The 2m/70cm/1.2ghz pre-amp setting for the 9100 is designed to power an external pre-amp - doesn't do anything for the VHF+ bands at all.
Showing posts with label VHF. Show all posts
Showing posts with label VHF. Show all posts
Friday, February 15, 2013
Tuesday, September 25, 2012
6m loop problem - BIOLOGICAL!!!
Wow, I guess I just live and learn...
I few weeks, perhaps months now I suppose, my 6m loop stopped being resonant on 50.125. Really weird - I mean, it looked fine and was hanging right where it had been for a while and I hadn't done ANYTHING with it except use it. I really didn't understand what was going on.
So, last weekend I dropped the antenna and tried to re-adjust it so that it would be resonant (again!) on 50.125 +/-. It was really strange; I'd tune/adjust it, raise it up 20' or so, think that I'd just about got it and then it would change on me. It was really frustrating. So, I adjusted it "one last time" and hauled it up into the air.
Wouldn't you know; it wouldn't tune on my 9100! My 7600 would tune it up, but that didn't make a whole lot of sense to me. I used my antenna analyzer and it was around 3:1 match!!! WHAT??!!?? ARGHH!!
(In case you haven't followed my rants recently, I've have a bad run of radio luck...)
Time passes... And now it's this afternoon - beautiful day and I have about an hour to kill until my next activity kicks up; sounds like a good time to take a look at the 6m loop problem. So, I dropped the antenna again, got out the M2 6m loop PDF and adjusted all the parts to the specs in the PDF. HOWEVER, when I was banging on the metal trying to shift parts around, ants started crawling out of the aluminum tubing! A LOT of ANTS - I mean, tons!!! How strange? Anyway, I kept on making noise and gave them a little while to clear out.
I went back later and it seemed like they'd moved on - I guess most of them did anyway. So I hauled the antenna back up in the air and guess what - 1.2:1 match :)
My "moral of the story is this", there is always a reason - it just might be stranger than what you think it is!
73 de KJ4WLH
I few weeks, perhaps months now I suppose, my 6m loop stopped being resonant on 50.125. Really weird - I mean, it looked fine and was hanging right where it had been for a while and I hadn't done ANYTHING with it except use it. I really didn't understand what was going on.
So, last weekend I dropped the antenna and tried to re-adjust it so that it would be resonant (again!) on 50.125 +/-. It was really strange; I'd tune/adjust it, raise it up 20' or so, think that I'd just about got it and then it would change on me. It was really frustrating. So, I adjusted it "one last time" and hauled it up into the air.
Wouldn't you know; it wouldn't tune on my 9100! My 7600 would tune it up, but that didn't make a whole lot of sense to me. I used my antenna analyzer and it was around 3:1 match!!! WHAT??!!?? ARGHH!!
(In case you haven't followed my rants recently, I've have a bad run of radio luck...)
Time passes... And now it's this afternoon - beautiful day and I have about an hour to kill until my next activity kicks up; sounds like a good time to take a look at the 6m loop problem. So, I dropped the antenna again, got out the M2 6m loop PDF and adjusted all the parts to the specs in the PDF. HOWEVER, when I was banging on the metal trying to shift parts around, ants started crawling out of the aluminum tubing! A LOT of ANTS - I mean, tons!!! How strange? Anyway, I kept on making noise and gave them a little while to clear out.
I went back later and it seemed like they'd moved on - I guess most of them did anyway. So I hauled the antenna back up in the air and guess what - 1.2:1 match :)
My "moral of the story is this", there is always a reason - it just might be stranger than what you think it is!
73 de KJ4WLH
Thursday, September 13, 2012
2m HO Loop Rebuild Project
I had a really high SWR on my 6m loop which meant that I needed to drop it to see what was going on. Since the loop mounting system also holds my 2m and 70cm loops, I decided to rebuild my 2m stack.
I have a 2m pre-amp that I've wanted to get in action for a while. I also have a M2 2m cable phasing set, which would be really great if I had a 2nd loop. So, I placed my order with HEO and ordered the final piece.
My goal is to have a pair if M2 2m HO loops, with a pre-amp mounted and up in the air by the end of the weekend.
Wish me luck!
73de KJ4WLH
I have a 2m pre-amp that I've wanted to get in action for a while. I also have a M2 2m cable phasing set, which would be really great if I had a 2nd loop. So, I placed my order with HEO and ordered the final piece.
My goal is to have a pair if M2 2m HO loops, with a pre-amp mounted and up in the air by the end of the weekend.
Wish me luck!
73de KJ4WLH
Tuesday, September 11, 2012
2m vertical antenna relocation worked!
I've been having difficulty over the past few months trying to hit my favorite D-Star repeater from my QTH. It's weird, nothing in my "control" changed - but one day, out of the blue, I could no longer hit the repeater with 2-3 watts of power.
Anyway, over the past weekend, I just finally resolved to move "things" around and see how that might play out - and guess what! Yeah, it worked. I relocated my 2m/70cm vertical to another location in the back yard and I'm back to hitting the repeater with just a couple of watts of power.
Nice.
Sometimes I wonder how any of this stuff works at all...
73 de KJ4WLH
Anyway, over the past weekend, I just finally resolved to move "things" around and see how that might play out - and guess what! Yeah, it worked. I relocated my 2m/70cm vertical to another location in the back yard and I'm back to hitting the repeater with just a couple of watts of power.
Nice.
Sometimes I wonder how any of this stuff works at all...
73 de KJ4WLH
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