Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: 14.318  (Read 1500 times)
K3SI
Member

Posts: 6




Ignore
« on: January 05, 2007, 09:28:57 AM »

anybody else hearing carrier with machine type noise on this freq? I have it 24/7
Logged
KF7CG
Member

Posts: 875




Ignore
« Reply #1 on: January 05, 2007, 12:24:04 PM »

Is there an old PC around being used for something. This is the main oscillator frequency of the old IBM color PC's and XT's. Their nominal clock frequency was 4.77 MHz but the actual oscillator frequency was about 14.318 since they used a divide by three digital circuit to get the 33% duty cycle waveform needed by the older Intel processors. The oscillator was used to provide reference signals for the older color cards and supply the color burst frequency for generating signals going to color TVs.  TV color burst is at approximately 3.580 MHz which is approximately 14.318 divided by four.

I hope this gives you a few ideas of where to check.

KF7CG
Logged
KB9CRY
Member

Posts: 4283


WWW

Ignore
« Reply #2 on: January 05, 2007, 06:58:28 PM »

There is no DX up at that frequency.


Why are you even listening there?


Sri,  hope you get your answers.

Phil
Logged
WB5OMP
Member

Posts: 3




Ignore
« Reply #3 on: January 15, 2007, 11:05:45 AM »

There is a real problem at 14.316/318 mhz, no DX there, but on Sundays there is a users net at 1700z which is frequently drowned out by a heterodyne. I have noticed it as I traveled throughout the west as well. It is sometimes 10 over here in western Washington state.
Steve
Logged
KF7CG
Member

Posts: 875




Ignore
« Reply #4 on: January 16, 2007, 07:12:16 AM »

It sounds as if you have discovered a nest of poorly sheilded TVs or Video distribution systems. 14.318 is the fourth harmonic of the TV color burst signal. Try checking at or around 3.795 for another signal. This is the actual color burst frequenciy being used. Many games and other video appliances use a digital oscilator on 14.318 and divide down. This produces very harmonic rich outputs.

Even one older TV can cover quite an area.

KF7CG
Logged
N0FPE
Member

Posts: 370




Ignore
« Reply #5 on: January 16, 2007, 01:40:31 PM »

dont hear thing here in Phoenix on 14.318. I however do hear a few of our south of the border friends on 14.316 and they seem to have no problem hearing each other. Go figure..

Dan
Logged
AE6CP
Member

Posts: 39




Ignore
« Reply #6 on: April 25, 2007, 09:35:59 PM »

I've got it too!! It just popped up a couple weeks ago. I can hear it every 15-16 KC's but the highest reading is right at 14.318, it's 10 over S9 It appears around 13.8 MC and continues every 16 KC's until about 15 MC. It's taken over 20 meters!!

This is how I found this thread, I typed in 'RFI at 14.318' in the Google search bar. I live in an apartment complex so God knows what the new neighbors brought to the RFI party.
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!