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Search found 45 matches

by Rich
Wed Nov 13, 2019 5:51 am
Forum: Metro Detroit/SE Michigan
Topic: WPON WCXI Updates - 2019
Replies: 119
Views: 13569

Re: WPON WCXI Updates - 2019

... I suspect that the signal will be much less than the predicted . David Gleason of americanradiohistory.com has a lot of experience and examples from Central and South America where stations would relocate the TL and increase from 10 kW to 100 kW with very disappointing results. For an example, ...
by Rich
Tue Nov 12, 2019 7:15 am
Forum: Metro Detroit/SE Michigan
Topic: WPON WCXI Updates - 2019
Replies: 119
Views: 13569

Re: WPON WCXI Updates - 2019

Noting the link below are you in the blue contour? Those contours are for the longtime, former TX site near Fenton. They are meaningless since the station now broadcasts from Wixom. The graphic below shows their CP daytime contours for the tx site near Wixom. The NAD 27 coordinates for the site are...
by Rich
Tue Nov 05, 2019 5:21 am
Forum: Engineering & DX'ing
Topic: Your best ever car radio?
Replies: 61
Views: 2526

Re: Your best ever car radio?

The best radio in a car I have owned is the stock radio in my 2016 Toyota Corolla LE. It receives a 530 kHz TIS station located >35 miles from me, having a field intensity of <50 µV/m at my location. The audio from it is noisy, as one would expect, but it is certainly "listenable" (at least for a sh...
by Rich
Tue Nov 05, 2019 5:08 am
Forum: Metro Detroit/SE Michigan
Topic: Remember when...
Replies: 9
Views: 1071

Re: Remember when...

Mega Hertz wrote:
Sat Nov 02, 2019 8:54 pm
...radio stations had someone on staff 24 hours a day?...
In the 1960s, WJR had at least two engineers on active duty, 24/7/365.

WJR had a total, full-time staff headcount of about 125 back then.

Rich (ex-WJR Engineering staffer)
by Rich
Sat Oct 26, 2019 10:12 am
Forum: Engineering & DX'ing
Topic: WJR-WWJ Daytime Groundwave vs. Distance Comparison
Replies: 20
Views: 672

Re: WJR-WWJ Daytime Groundwave vs. Distance Comparison

Below is a clip from the FCC website showing the daytime RMS field of WWJ at a horizontal distance of 1 km, for 50 kW of transmitter power.

The RMS value in my earlier graphic agrees nicely with the RMS values shown in the FCC data for WWJ.

Image
by Rich
Sat Oct 26, 2019 7:32 am
Forum: Engineering & DX'ing
Topic: WJR-WWJ Daytime Groundwave vs. Distance Comparison
Replies: 20
Views: 672

Re: WJR-WWJ Daytime Groundwave vs. Distance Comparison

The text and graphic in the post next above was edited to better describe the point being made (hopefully).
by Rich
Fri Oct 25, 2019 5:37 pm
Forum: Engineering & DX'ing
Topic: WJR-WWJ Daytime Groundwave vs. Distance Comparison
Replies: 20
Views: 672

Re: WJR-WWJ Daytime Groundwave vs. Distance Comparison

... I am sure if you could measure the signal from a directional antenna in ALL directions (at the same distance) it would have an average signal equal to the single tower's signal. ... An old analogy about this is that an inflated spherical balloon, when squeezed, still has the same volume within ...
by Rich
Fri Oct 25, 2019 8:21 am
Forum: Engineering & DX'ing
Topic: WJR-WWJ Daytime Groundwave vs. Distance Comparison
Replies: 20
Views: 672

Re: WJR-WWJ Daytime Groundwave vs. Distance Comparison

... Real antennas utilize elements which theoretically oscillate in one dimension, like a monopole or dipole. ... In practice, the free-space, far-field gain of a 1/2-wavelength, center-fed dipole (units of dBd) often is used as a reference for the gain of other antennas. As can be shown by mathema...
by Rich
Fri Oct 25, 2019 8:13 am
Forum: Engineering & DX'ing
Topic: WJR-WWJ Daytime Groundwave vs. Distance Comparison
Replies: 20
Views: 672

Re: WJR-WWJ Daytime Groundwave vs. Distance Comparison

Sorry for this and the next post, but two edits of my original comments were posted, and I couldn't find a way to delete them.
by Rich
Fri Oct 25, 2019 6:46 am
Forum: Engineering & DX'ing
Topic: WJR-WWJ Daytime Groundwave vs. Distance Comparison
Replies: 20
Views: 672

Re: WJR-WWJ Daytime Groundwave vs. Distance Comparison

ERP always depends on the reference efficiency for 1 kW @ 1 km. ...Another reference is 314 mV/m for a theoretical lossless 1/4 wavelength. ... The FCC convention is to define the efficiency of an antenna system used by AM broadcast stations to be the e-field intensity it produces 1 km away from it...
by Rich
Thu Oct 24, 2019 8:46 am
Forum: Engineering & DX'ing
Topic: WJR-WWJ Daytime Groundwave vs. Distance Comparison
Replies: 20
Views: 672

Re: WJR-WWJ Daytime Groundwave vs. Distance Comparison

WWJ in their major lobe puts out 586KW concentrated power daytime ... Below is a plot of the Effective Radiated Power (ERP) and the resulting 1.0 and 0.1 mV/m field intensity contours of WWJ during the daytime. According to FCC data and methodology, WWJ radiates a maximum ERP of 381 kW in the horiz...
by Rich
Tue Oct 22, 2019 11:46 am
Forum: Engineering & DX'ing
Topic: WJR-WWJ Daytime Groundwave vs. Distance Comparison
Replies: 20
Views: 672

Re: WJR-WWJ Daytime Groundwave vs. Distance Comparison

No, WWJ does not have same field in/near Toledo as WJR. The chart shows the WWJ field along an azimuth bearing of 335 degrees from their transmit site. Toledo does not lie on that radial. WWJ is a directional station, and radiates relatively low ERP toward Toledo. OTOH, WJR radiates the same ERP tow...
by Rich
Sun Oct 20, 2019 11:40 am
Forum: Engineering & DX'ing
Topic: WJR-WWJ Daytime Groundwave vs. Distance Comparison
Replies: 20
Views: 672

WJR-WWJ Daytime Groundwave vs. Distance Comparison

Below is a comparison of the daytime groundwave fields of WJR and WWJ* for a range of 10 to 60 radial miles from their respective transmit sites. The compass bearing for this radial is in the direction of the maximum power radiated by the daytime array of WWJ, which is oriented at N335°E. WJR is abo...
by Rich
Wed Oct 16, 2019 6:34 am
Forum: Engineering & DX'ing
Topic: WWJ in Kentucky
Replies: 4
Views: 310

Re: WWJ in Kentucky

Below are plots of the 1.0 and 0.1 mV/m daytime (groundwave) coverage contours for WWJ and other 950 kHz stations nearby.

Lots of co-channel interferers radiating towards Cincinnati, on that frequency.

Image