Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Old April 6th 04, 05:34 AM
Dave Pitzer
 
Posts: n/a
Default Beginner's question

I have a CC Radio Plus (Sangean) AM/FM/TV/WX radio (from C. Crane Co.) I
enjoy broadcasr band DX'ing and this radion does a super job with just it's
built-in ferrite antenna. I have logged AM BC stations from practically
every state east of the Mississippi.

Best reception is, of course, at night. But.... for some reason WABC (New
York City) comes in poorly at night even though it's xmitter is only 80
miles away. The signal fades to next to nothing and then increases to very
loud but extremely distorted then will be loud and clear for a while.
(During the day this station's signal is fine.) On the same evening,
stations in Georgia (WSB, Atlanta), Illonois (WGN, Chicago), Michigan (WJR,
Detroit), etc., etc. come in fine 90% of the time.

Do I need an external antenna for the closer WABC?????

Thanks,

Dave Pitzer
Pocono Lake, PA
========================



  #2   Report Post  
Old April 6th 04, 06:24 AM
Rick Frazier
 
Posts: n/a
Default

Dave:

I don't know the specifics of WABC, but many radio stations have different
power and antenna patterns for night time operation than they do for daytime.
I would suppose that WABC is a clear channel station that can transmit 24 hours
a day at 50KW (50,000 watts). Even as such, the antenna pattern may be nearly
omnidirectional during the day, and highly directional north and south at
night, and you may be sitting in one of the "nulls", hence you get poor
reception at night.

As you are close by, you may be able to call them directly and ask what their
power and antenna patterns are, if you are interested in finding out if this is
the issue...

Of course, atmospheric conditions change dramatically after the sun goes down,
and they could be accounting for the signal fluctuations you are
experiencing...

Thanks
--Rick AH7H

Dave Pitzer wrote:

I have a CC Radio Plus (Sangean) AM/FM/TV/WX radio (from C. Crane Co.) I
enjoy broadcasr band DX'ing and this radion does a super job with just it's
built-in ferrite antenna. I have logged AM BC stations from practically
every state east of the Mississippi.

Best reception is, of course, at night. But.... for some reason WABC (New
York City) comes in poorly at night even though it's xmitter is only 80
miles away. The signal fades to next to nothing and then increases to very
loud but extremely distorted then will be loud and clear for a while.
(During the day this station's signal is fine.) On the same evening,
stations in Georgia (WSB, Atlanta), Illonois (WGN, Chicago), Michigan (WJR,
Detroit), etc., etc. come in fine 90% of the time.

Do I need an external antenna for the closer WABC?????

Thanks,

Dave Pitzer
Pocono Lake, PA
========================


  #3   Report Post  
Old April 6th 04, 12:39 PM
WB2JKX
 
Posts: n/a
Default


Dave Pitzer wrote in message
...
I have a CC Radio Plus (Sangean) AM/FM/TV/WX radio (from C. Crane Co.) I
enjoy broadcasr band DX'ing and this radion does a super job with just

it's
built-in ferrite antenna. I have logged AM BC stations from practically
every state east of the Mississippi.

Best reception is, of course, at night. But.... for some reason WABC (New
York City) comes in poorly at night even though it's xmitter is only 80
miles away. The signal fades to next to nothing and then increases to very
loud but extremely distorted then will be loud and clear for a while.
(During the day this station's signal is fine.) On the same evening,
stations in Georgia (WSB, Atlanta), Illonois (WGN, Chicago), Michigan

(WJR,
Detroit), etc., etc. come in fine 90% of the time.

Do I need an external antenna for the closer WABC?????

Thanks,

Dave Pitzer
Pocono Lake, PA
========================

You're still close enough to receive the groundwave signal, but at night
skywave signal will cause constructive and destructive interference as the
phase relationship between the twoslowly changes. I experience the same
thing in NW NJ.


  #4   Report Post  
Old April 6th 04, 01:47 PM
Jack Painter
 
Posts: n/a
Default

"WB2JKX" wrote in message
...

Dave Pitzer wrote in message
...
I have a CC Radio Plus (Sangean) AM/FM/TV/WX radio (from C. Crane Co.) I
enjoy broadcasr band DX'ing and this radion does a super job with just

it's
built-in ferrite antenna. I have logged AM BC stations from practically
every state east of the Mississippi.

Best reception is, of course, at night. But.... for some reason WABC

(New
York City) comes in poorly at night even though it's xmitter is only 80
miles away. The signal fades to next to nothing and then increases to

very
loud but extremely distorted then will be loud and clear for a while.
(During the day this station's signal is fine.) On the same evening,
stations in Georgia (WSB, Atlanta), Illonois (WGN, Chicago), Michigan

(WJR,
Detroit), etc., etc. come in fine 90% of the time.

Do I need an external antenna for the closer WABC?????

Thanks,

Dave Pitzer
Pocono Lake, PA
========================

You're still close enough to receive the groundwave signal, but at night
skywave signal will cause constructive and destructive interference as the
phase relationship between the twoslowly changes. I experience the same
thing in NW NJ.


One NJ station that I can't remember at the moment told me that I was the
Southern-most reception report they had (Princeton to Virginia Beach, Va).
They change from 100,000w daytime to 1,000w nighttime. Normally a powerful
Florida station overpowers their transmission.

Jack


  #5   Report Post  
Old April 6th 04, 04:04 PM
Cecil Moore
 
Posts: n/a
Default

Dave Pitzer wrote:
Best reception is, of course, at night. But.... for some reason WABC (New
York City) comes in poorly at night even though it's xmitter is only 80
miles away. The signal fades to next to nothing and then increases to very
loud but extremely distorted then will be loud and clear for a while.


More than likely, you are getting interference between the ground wave
and the sky wave as the strength and path of the sky wave varies with
atmospheric conditions. I don't know of a cure. I sometimes have the
same problem with the same radio tuned to WTAW, 40 miles away.
--
73, Cecil, W5DXP



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----


  #6   Report Post  
Old April 6th 04, 04:33 PM
Dave Pitzer
 
Posts: n/a
Default

Gents,

I think the suggestion that the ground and sky wave are "fighting" each
other after sunset is the answer. This would account for the "wierd"
phase-shifting audio sounds that accompany the shifts in signal strength.

The links below show that I'm between the local and distant coverage pattern
contours. (I'm a little east of Allentown, PA.)

http://www.radio-locator.com/cgi-bin...atus=L&hours=D

http://www.radio-locator.com/cgi-bin...atus=L&hours=N


Incidentally, www.radio-locator.com is a good resource for BCB Dxing.

Dave Pitzer
================
"Dave Pitzer" wrote in message
...
I have a CC Radio Plus (Sangean) AM/FM/TV/WX radio (from C. Crane Co.) I
enjoy broadcasr band DX'ing and this radion does a super job with just

it's
built-in ferrite antenna. I have logged AM BC stations from practically
every state east of the Mississippi.

Best reception is, of course, at night. But.... for some reason WABC (New
York City) comes in poorly at night even though it's xmitter is only 80
miles away. The signal fades to next to nothing and then increases to very
loud but extremely distorted then will be loud and clear for a while.
(During the day this station's signal is fine.) On the same evening,
stations in Georgia (WSB, Atlanta), Illonois (WGN, Chicago), Michigan

(WJR,
Detroit), etc., etc. come in fine 90% of the time.

Do I need an external antenna for the closer WABC?????

Thanks,

Dave Pitzer
Pocono Lake, PA
========================





  #7   Report Post  
Old April 6th 04, 08:26 PM
Robert Spooner
 
Posts: n/a
Default

Dave,

If the ground and sky waves come in at different angles, you may be able
to rotate and tilt the radio to receive one and null out the other. The
optimum angle may change with the time of day as the ionosphere changes.

73,
Bob AD3K

Cecil Moore wrote:
Dave Pitzer wrote:

Best reception is, of course, at night. But.... for some reason WABC (New
York City) comes in poorly at night even though it's xmitter is only 80
miles away. The signal fades to next to nothing and then increases to
very
loud but extremely distorted then will be loud and clear for a while.



More than likely, you are getting interference between the ground wave
and the sky wave as the strength and path of the sky wave varies with
atmospheric conditions. I don't know of a cure. I sometimes have the
same problem with the same radio tuned to WTAW, 40 miles away.
--
73, Cecil, W5DXP



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----


--
Robert L. Spooner
Registered Professional Engineer
Associate Research Engineer
Intelligent Control Systems Department

Applied Research Laboratory Phone: (814) 863-4120
The Pennsylvania State University FAX: (814) 863-7841
P. O. Box 30
State College, PA 16804-0030

  #8   Report Post  
Old April 7th 04, 01:54 AM
Richard Harrison
 
Posts: n/a
Default

Dave Pitzer wrote:
"WABC (New York City) comes in poorly at night even though its xmtter is
only 80 miles away."

80 miles is within groundwave range of WABC. 770 KHz should reach that
far in the daylight hours as well as at night. At night, the ionosphere
reconfigures allowing a reflected wave from the station to reach your
receiver. While the groundwave is subject to ittle if any variation, the
skywave is subject to many variations. Thats just the beginning of the
problem. All U.S. stations share their assignments with other stations
operating on the same frequencies. If the desired station is not
interfered between its own groundwave and skywave (you are out of
groundwave range) it is still likely to be interfered by other stations
sharing its frequency or even interfered by adjacent channel stations.
When these undesired stations fade in, they can suppress reception of
the desired station by taking over the receiver`s automatic gain control
circuit.

To accomodate multiple assignments on a single carrier frequency, FCC
often requires new assignees to include a null toward one or more
aditional existing stations, especially at night, in the new station`s
radiation pattern. If the reduction in potential interference is deemed
insufficient, the new station may be required to reduce power as well as
switch directional patterns during nighttime hours. The new station may
be the oldest station on the frequency if it has decided to relocate or
make some other modification to its license terms.

So, WABC may have directional coverage of its area which it switches at
nightfall and daybreak. I have an FCC book showing all the assignments
but it is very out of date.

Best regards, Richard Harrison, KB5WZI

  #9   Report Post  
Old April 7th 04, 01:03 PM
Jeppe
 
Posts: n/a
Default

On Tue, 06 Apr 2004 04:34:00 GMT, "Dave Pitzer"
wrote:
The signal fades to next to nothing and then increases to very
loud but extremely distorted then will be loud and clear for a while.
(During the day this station's signal is fine.)


Your problem is selective fading. You are probably using an ordinary
AM receiver. When the selective "notch" hits the carrier it gets very
weak and the automatic volume control turns up the RF-amplification.
But at the same time the sidebands are not nulled out to the same
degree. So you get a loud distorted audio signal resulting from
relatively strong sidebands and a very weak carrier.

If you couldn get a receiver with single sideband reception or - even
better - fase-locked "sync" reception you would get better sound. You
would still get some distortion but it would be of a much less
malignant (linear) kind. I would thnk that this is a more realistic
solution than trying to null out the different signal path with some
sort of sophisticated antenna. I use a Sony "sync" shortwave receiver
myself for listening to eg. BBC with good result.

Jeppe
  #10   Report Post  
Old April 7th 04, 02:31 PM
Robert A. Miller
 
Posts: n/a
Default

I have a CCRadio and the Select-A-Tenna receiving loop that the same
people sell. The loop works extremely well on weak AM signals, but
only if that frequency is clear of other nearby stations. **If** the
frequency is clear, and there is just the barest signal from the
station you want to hear, the loop will really pull it up and make it
loud.

You can also homebrew these loops, and you might find plans on the
internet somewhere.

You are lucky in that your receiver has an AM antenna terminal, so you
can attach an outside wire. I'd certainly try that -- wouldn't cost
much at all.

Bob
k5qwg


On Tue, 06 Apr 2004 04:34:00 GMT, "Dave Pitzer"
wrote:

I have a CC Radio Plus (Sangean) AM/FM/TV/WX radio (from C. Crane Co.) I
enjoy broadcasr band DX'ing and this radion does a super job with just it's
built-in ferrite antenna. I have logged AM BC stations from practically
every state east of the Mississippi.

Best reception is, of course, at night. But.... for some reason WABC (New
York City) comes in poorly at night even though it's xmitter is only 80
miles away. The signal fades to next to nothing and then increases to very
loud but extremely distorted then will be loud and clear for a while.
(During the day this station's signal is fine.) On the same evening,
stations in Georgia (WSB, Atlanta), Illonois (WGN, Chicago), Michigan (WJR,
Detroit), etc., etc. come in fine 90% of the time.

Do I need an external antenna for the closer WABC?????

Thanks,

Dave Pitzer
Pocono Lake, PA
========================



Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Question about Full Wave loop HaveHFWillTravel Antenna 8 April 10th 04 08:26 PM
Stupid question G5RV Ken Bessler Antenna 17 January 9th 04 12:06 PM
Seperation question???? thanks [email protected] Antenna 0 October 7th 03 07:57 PM
Yagi / Beam antenna theory question... Nick C Antenna 12 October 5th 03 12:15 PM
Question about attenuators ... Doug McLaren Antenna 2 August 31st 03 04:20 AM


All times are GMT +1. The time now is 08:52 PM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017