wibg radio 99

[CHJ1950]

 In Hy Lit's heyday there, I would listen to the 50,000 watt WIBG in northern monmouth county. After sunset the station couldn't be received at all, 60 miles from Philly. Yet, 5,000 watt WFIL came in loud and clear.
 Can someone tell me if this was due to a power reduction, or WIBG pointed it's antenna in a southerly direction?

[kfsr]

WIBG operated on a Canadian clear channel with five towers directional day, and at 10,000 watts 4 towers directional night. WFIL operated on a low-end-of-the-dial regional channel with three towers. WFIL had greater bandwidth, superior day and night coverage, and was less directional than WIBG. WIBG had nighttime signal problems to the north, the south and the west..even in it's primary coverage area.

[cyber]

I remember their big "going to 50,000 watts" promotion at Independence Hall. I think the date was on or around Feb.22, 1959. I do remember it was snowing and the only "air personality" on the sidewalk handing out autographed pictures was car dealer Harold B. Robinson. The real jocks had sense enough to stay indoors.

[oaktree]

The WIBG signal always was problematic.  It was either directional right into the ground and went nowhere or dissipated in thin air at night. It was a very "tight" pattern from the start of the 50,000 watt boost.

I lived in Wilmington and regularly heard WNOX in Knoxville like a local on many nights.  It was tough to hear Joey Reynolds and John Records Landecker on WIBG even with great lengths of thin solid copper wire out the window...but, we got by.

[Sam Lit]

While the Philadelphia 990 KHz pattern was, and is critically tight to the north and west to protect the Canadian neighbors, primarily CKGM, it loops 268,000+ watts daytime to the SE, (rtetro will have to chime in for the current nighttime specks, as he has just upgraded the night pattern). So, during Hy’s tenure at WIBG, he was often heard saying, “It’s Hy Lit, from your door to the shore”, as WIBG was strong and clear down the shore.
    As for WFIL, 5,000 watts at the lower spectrum 560 KHz, has a relative signal power equivalent of 50,000 watts on 990 KHz, due to spectrum transmission variations. However, looking back at the late 60’s and early 70’s, WFIL was also using a 25,000 watt modulator in their 5,000 watt transmitter, therefore they were able to generate amplitude modulation positive peak of 155%, and sometimes greater, without harmonic distortion. This also gave Philadelphia 560 the appearance of a broader position on the AM dial, as generating greater amounts of positive peak amplitude modulation will deliver a broader spacing appearance on the dial. In the early 70’s, the FCC ruled that positive modulation peaks be limited to 125% in order to curtail this practice of what is now considered over modulation, analogue.
   Even with the over modulation practice and the lower spectrum positioning, WFIL was and is a little harder to hear at the NJ coastal towns, due to their direction pattern, which is more liberal to the NW.

[amfmsw]

In reference to WFIL-AM technical abilities in 1968 or so...

1.  There's no such thing as a 25000watt am modulator into an AM 5000 watt transmitter.  It does not, has not ever existed.  FM's DO use power amps called exciters to be multiplied in power, but it's 10 to 100 watts to thousands.  Am does not work that way.  Were you speaking of 102.1 WFIL-FM?

2.  WFIL never modulated to 155%.  Impossible on the Gates/RCA/Continental plate modulated transmitters of the day.  If it could, it would sound like total crap, as the AM radios of the day would be totally overloaded in the IF sections.  WFIL sounded great, WIBG sounded fuller and richer in my opinion.  Archie Sitchell, WIBG Chief Engineer liked full, EQ'd modulation, slight reverb, and ran an oscilliscope on the modulation to keep it legal.  Side by side aircheck comparisons will bear this out.

3.  At 560 Kc, WFIL did not particularly enjoy wider audio bandwidth.  It DID, however, enjoy a longer wavelength, which carried the signal further on fewer watts.  The lower the frequency, the longer the wavelength.  Part of WIBG's difficulties were the impedance matching of the towers, the phase "swishing" as you drove between lobes put out by each stick (then 5), and the problematic, water cooled, custom built RCA "Ampliphase" transmitters Wibbage used.  50kw for day, and a seperate 10kw for night and back-up for servicing the main momma.  Most of the stations in this area used RCA transmitters because ANY part needed in an emergency was available with a short ride to the factory in Camden.   

We need Frank Hogan to speak for WFIL.

[simonbarrsinister]

mplitude-frequency-short wins! 

[Sam Lit]

Bill, I appreciate and thank you for your expertise on this matter. What I should have said, is they took a modulator section from a 25,000 watt transmitter and put it in their 5,000 watt transmitter. The original WFIL equipment wound up at 117 ridge pike, so rtetro can perhaps speak of the exact modification process, and capacity of WFIL’s original transmitter/s. They demonstrated with ease, what we consider today as being over modulation until the FCC defined positive peak at 125%.

[chuckydoll]

AM 990 (WIBG/WZZD/WNTP) runs 50 kw-D, 10 kw-N, DA-2. The main lobe goes southeast day and night to protect CBW-990 in Winnipeg. CKGM was on 980 until the early 90's.

WFIL runs 5 kw-U, DA-2. On day pattern the main lobes are NW/SE, which is why Famous 56 beat Wibbage in Montgomery County. Night pattern has the main lobe SE.

[LA_Guy]

Back in the late 1960's/early 1970's, Gates Radio (now Harris Broadcast) made a 5 kW AM transmitter with a 10 kW modulator (with its own power supply). LOTS of 5 kW AM stations bought this rig, as it could EASILY modulate in excess of 200% positive.  This rig (and others like it that were modded by engineers) are the reason the FCC REDUCED the positive peak limit to 125%. Prior to the rule change, there was NO LIMIT to how much an AM station could modulate in the positive direction.  The reason for the limit was to reduce splatter. NRSC has made the positive peak limit redundant, and it's now yet another FCC rule with no reason for its existance.