RadioReference on Facebook   RadioReference on Twitter   RadioReference Blog
 

Go Back   The RadioReference.com Forums > Amateur Radio > Amateur Radio General Discussion


Amateur Radio General Discussion - General discussion forum for amateur radio topics not covered by the above forums.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #41 (permalink)  
Old 10-14-2018, 9:00 AM
Member
   
Join Date: Feb 2017
Posts: 157
Default

Wow... I was just digging into your post above about the preselector.. That is certainly the issue I'm having.. Even the screen shots from RTL are spot on what I'm seeing.

Not sure what I'm going to do about it yet though... at least now I know what the problem is...
Reply With Quote
Sponsored links
  #42 (permalink)  
Old 10-14-2018, 10:30 AM
RFI-EMI-GUY's Avatar
Member
  Amateur Radio Operator
Amateur Radio
 
Join Date: Dec 2013
Posts: 2,382
Default

Quote:
Originally Posted by Murphy625 View Post
Wow... I was just digging into your post above about the preselector.. That is certainly the issue I'm having.. Even the screen shots from RTL are spot on what I'm seeing.

Not sure what I'm going to do about it yet though... at least now I know what the problem is...
I thought you might spot that screen shot!

Sent from my SM-T350 using Tapatalk
__________________
"Have Spectrum Analyzer, - Will travel" "Going Green"
Reply With Quote
  #43 (permalink)  
Old 10-14-2018, 1:37 PM
Member
   
Join Date: Feb 2017
Posts: 157
Default

Quote:
Originally Posted by RFI-EMI-GUY View Post
I thought you might spot that screen shot!

Sent from my SM-T350 using Tapatalk
I would have never figured that out without you.... thank you very much...

I'm not sure what I want to do with it though.. I don't really need a preselector for the entire spectrum.. just something to filter 80,40 and 2m bands.... 70cm is quiet as it is..

I figure for the 2 meter band, just using the correct antenna instead of a 80ft long dipole would solve that problem..

So really, I just need a band pass filter for 80 and 40.. I'm wondering if there is a cheaper option than a $100 board..
Reply With Quote
  #44 (permalink)  
Old 10-14-2018, 2:29 PM
RFI-EMI-GUY's Avatar
Member
  Amateur Radio Operator
Amateur Radio
 
Join Date: Dec 2013
Posts: 2,382
Default

Quote:
Originally Posted by Murphy625 View Post
I would have never figured that out without you.... thank you very much...

I'm not sure what I want to do with it though.. I don't really need a preselector for the entire spectrum.. just something to filter 80,40 and 2m bands.... 70cm is quiet as it is..

I figure for the 2 meter band, just using the correct antenna instead of a 80ft long dipole would solve that problem..

So really, I just need a band pass filter for 80 and 40.. I'm wondering if there is a cheaper option than a $100 board..
You will probably do fine with a resonant 2M a on that band if you have no paging stations near by.

As far as 80M and 40M filters, there are tons of articles on making filters for those bands. Any of the QRP receiver kits should have a schematic. Otherwise there were preselectors sold for shortwave receivers that can be manually tuned. You could even get a defunct antique radio like a Yaesu FRG7 and carve the preselector parts from it. Another possibility might be minicircuits as long as you choose band pass filters or combination of HP/LP covering your bands.
__________________
"Have Spectrum Analyzer, - Will travel" "Going Green"
Reply With Quote
  #45 (permalink)  
Old 10-14-2018, 3:25 PM
Member
  Amateur Radio Operator
Amateur Radio
 
Join Date: Aug 2015
Location: Santa Monica, Ca.
Posts: 327
Default noise

It is a halogen light on a dimmer.
Reply With Quote
Sponsored links
  #46 (permalink)  
Old 10-14-2018, 6:27 PM
RFI-EMI-GUY's Avatar
Member
  Amateur Radio Operator
Amateur Radio
 
Join Date: Dec 2013
Posts: 2,382
Default

Quote:
Originally Posted by Murphy625 View Post
Wow... I was just digging into your post above about the preselector.. That is certainly the issue I'm having.. Even the screen shots from RTL are spot on what I'm seeing.

Not sure what I'm going to do about it yet though... at least now I know what the problem is...
Glad to help!

This one is quite entertaining. This guys SDR is getting splattered by a neighbors Guitar amp. Knowing what I do about guitarists from the Jimi Hendricks days, distortion was the name of the gain, the more the better. It is conceivable that the guitar amp is in oscillation and radiating all that crap. Still these SDR need RF preselection to operate in the "real world".

https://www.youtube.com/watch?v=BFZ1Vf5qy7o
__________________
"Have Spectrum Analyzer, - Will travel" "Going Green"
Reply With Quote
  #47 (permalink)  
Old 10-14-2018, 7:43 PM
Member
   
Join Date: Feb 2017
Posts: 157
Default

I'm sitting here listening to a 2 meter "ham net" something or other on 146.445.. and I'm thinking to my self.. "gee whiz, I wonder how much better a 2m antenna would do compared to the G5RV on the 144 band..

And then I start punching in call signs from this ham net thingy.. I figured they were somewhere local because the signals are clear... these guys are 175 - 200 miles from me via google maps (crow fly) distance tool.. And their signals are averaging 20db above the noise floor.. How is that possible? There's no way someone has an antenna sitting at 5000+ feet in Ohio.. that place is as flat as a pancake. I'm pretty sure they're going through a repeater because I can see the ctcss tones on the audio spectrum display..

I'm astonished that I can hear them so clearly.. so much so, I actually hit the record button in the SDR panel.

I stopped it after less than a minute and the file is about 6 megabytes.
Reply With Quote
  #48 (permalink)  
Old 10-14-2018, 7:56 PM
RFI-EMI-GUY's Avatar
Member
  Amateur Radio Operator
Amateur Radio
 
Join Date: Dec 2013
Posts: 2,382
Default

Quote:
Originally Posted by Murphy625 View Post
I'm sitting here listening to a 2 meter "ham net" something or other on 146.445.. and I'm thinking to my self.. "gee whiz, I wonder how much better a 2m antenna would do compared to the G5RV on the 144 band..

And then I start punching in call signs from this ham net thingy.. I figured they were somewhere local because the signals are clear... these guys are 175 - 200 miles from me via google maps (crow fly) distance tool.. And their signals are averaging 20db above the noise floor.. How is that possible? There's no way someone has an antenna sitting at 5000+ feet in Ohio.. that place is as flat as a pancake. I'm pretty sure they're going through a repeater because I can see the ctcss tones on the audio spectrum display..

I'm astonished that I can hear them so clearly.. so much so, I actually hit the record button in the SDR panel.

I stopped it after less than a minute and the file is about 6 megabytes.
They could be on a repeater, and then again they could be on a repeater that is linked with one local to you. I can hear the EOC in Tallahassee though I am in Orlando. There are numerous repeaters linked via SARnet.
__________________
"Have Spectrum Analyzer, - Will travel" "Going Green"
Reply With Quote
  #49 (permalink)  
Old 10-14-2018, 8:57 PM
Member
   
Join Date: Feb 2017
Posts: 157
Default

Quote:
Originally Posted by RFI-EMI-GUY View Post
They could be on a repeater, and then again they could be on a repeater that is linked with one local to you. I can hear the EOC in Tallahassee though I am in Orlando. There are numerous repeaters linked via SARnet.
They mentioned something about a "Echonet". I'll have to figure out how to find the closest one to me.
Reply With Quote
  #50 (permalink)  
Old 10-15-2018, 6:26 AM
W9BU's Avatar
Lead Wiki Manager
  RadioReference Database Admininstrator
Database Admin
Amateur Radio Operator
Amateur Radio
 
Join Date: Jul 2004
Location: Brownsburg, Indiana
Posts: 5,306
Default

Quote:
Originally Posted by Murphy625 View Post
They mentioned something about a "Echonet".
Echolink?

Introducing EchoLink
__________________
Lead Wiki Manager and Forum Moderator.

"The whole world's living in a digital dream. It's not really there, it's all on the screen." -- WB6ACU
Reply With Quote
  #51 (permalink)  
Old 10-18-2018, 1:33 AM
Member
   
Join Date: Feb 2017
Posts: 157
Default

Quote:
Originally Posted by W9BU View Post
Ya, but how do I tell which repeater closest to me was the one barking out the VHF I could hear?
Reply With Quote
  #52 (permalink)  
Old 10-18-2018, 2:26 AM
krokus's Avatar
Member
  Premium Subscriber
Premium Subscriber
 
Join Date: Jun 2006
Location: Southeastern Michigan
Posts: 3,360
Default

Quote:
Originally Posted by Murphy625 View Post
Ya, but how do I tell which repeater closest to me was the one barking out the VHF I could hear?
I think you were hearing a repeater in Howell.

https://repeaterbook.com/repeaters/f...&type=EchoLink


Sent using Tapatalk
__________________
Generic radio geek, in southeast Michigan.
PSR-500, TM-742, TM-V71,TH-78, HTX-420, IC-2AT, IC-2E (clone), Pro-39, BC-235XLT, TK-290, XTS-5000
Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -5. The time now is 3:17 AM.


Powered by vBulletin® Version 3.8.2
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
All information here is Copyright 2012 by RadioReference.com LLC and Lindsay C. Blanton III.Ad Management by RedTyger
Copyright 2015 by RadioReference.com LLC Privacy Policy  |  Terms and Conditions