AM Frequency of the Week - 700 kHz

[Buckeyes2001]

What can you all get on 700 AM?

Here in Vermilion, OH it is always WLW with a fair signal during the day and much stronger at night. They run I-BLOCK unfortunately which ruins 690 and 710 DXing at night from here.

 

[purpledevil]

700 KSEV-Tomball, TX "700 The Voice" airing conservative talk during the daytime. Depending how far south you get from the Tomball station at night in the metro of Houston, your WLW begins to overtake KSEV.

 

[radioman148]

Near north Chicago suburbs WLW day (weak), night (strong)

 

[ddsparxx]

In northern VA, I get WDMV Walkersville, MD, a daytimer with Spanish programming. Nights, it's WLW as usual. When WDMV was off the air few years ago, I once heard a very weak WLW during the daytime in the winter (skywave).

 

[RyanHoward]

Warminster PA(Philly 'burbs):

Daytime: zippo(maybe splatter from WPHE 690 or WOR 710, but that's about it)
Night: always WLW

 

[Cincinnati Kid]

What else here in Southwestern Ohio? --- WLW.

 

[rbrucecarter5]

Dominated in Houston by local KSEV day and night. At night, as long as WLW uses the power vampire HD, I can barely hear it when I null KSEV. On the rare occasions when they turn off HD, they are much easier to hear by nulling KSEV. Prior to HD and KSEV, they were an occasional wintertime daytime signal in Houston.
I also could get them daytime in Lubbock, TX, with a large loop and good radio. I no longer travel Lubbock to try in the HD era, but I suspect the HD power drop would eliminate that, too.

 

[schmave]

Pickerington, Ohio
Always WLW, same signal day and night. 7 on a 1-to-10 scale and HD blots out 690 and 710 completely. We're close enough to Cincinnati that it also can be heard on 680 and 720, albeit weakly. A little cancellation during the summer, hardly any during the winter.

 

[Buckeyes2001]

If WLW were ever to be off the air for any reason, what do you think might come in in its place? (Day or night)

 

[rfry]

... At night, as long as WLW uses the power vampire HD, I can barely hear it when I null KSEV. On the rare occasions when they turn off HD, they are much easier to hear by nulling KSEV. ...

I believe that AM broadcast stations radiate the same analog AM carrier power and analog AM modulation percentages when using HD as when they don't. The digital carriers do not occupy that same r-f spectrum, so they really shouldn't affect a good, analog-only AM receiver tuned to that analog center frequency.

Could you explain more about what you are experiencing?

 

[rbrucecarter5]

... At night, as long as WLW uses the power vampire HD, I can barely hear it when I null KSEV. On the rare occasions when they turn off HD, they are much easier to hear by nulling KSEV. ...

I believe that AM broadcast stations radiate the same analog AM carrier power and analog AM modulation percentages when using HD as when they don't. The digital carriers do not occupy that same r-f spectrum, so they really shouldn't affect a good, analog-only AM receiver tuned to that analog center frequency.

Could you explain more about what you are experiencing?

Broadcast engineers run around with field strength meters and don't observe a difference, but consumer radios have AGC circuits that mis-interpret HD stations. Once a station goes HD, it doesn't get out nearly as well as it used to - and doesn't penetrate buildings as well. Ask WBAP - they dumped HD years before adding 96.7 FM, because they are one of the few stations that actually cares about rural listeners. It was a DRAMATIC change. From barely receivable in Houston to blasting in almost like a local daytime. WOAI had a similar experience - you can bet Austin listeners were important to them!

 

[rfry]

Broadcast engineers run around with field strength meters and don't observe a difference, but consumer radios have AGC circuits that mis-interpret HD stations...

A modern, consumer-level AM broadcast receiver sold in the US has an RF/IF bandwidth of maybe 6 kHz at the -3 dB points, that is, 3 kHz above and below an analog carrier frequency centered in its passband.

In the parts of the radio spectrum where the digital carriers are transmitted, the receiver response is down at least 20 dB.

The highest level for the digital carriers on HD AM is about 27 dB below the unmodulated analog carrier. Those digital carriers use different parts of the r-f spectrum than the analog AM signal. They are located where the RF/IF response of the receiver tuned to that analog center frequency is down at least 20 dB.

So signals due to AM HD carriers in such receivers would be suppressed ~ 50 dB (or more) before the receiver AGC circuit could even detect them, which would produce a negligible change in AGC gain compared to that same signal with no HD carriers.

I'm no supporter of AM HD due mainly to its interference to adjacent channels by nighttime skywaves, but it does seem that something other then AGC action must account for the effects you report for WBAP and WOAI.

RF

 

[kilokat7]

From West Michigan, WLW and these stations on rare occasions:

WTUB Orange, MA.
KHSE Wylie, TX.
KSEV Tomball, TX.
KALL North SLC, UT.
XEDKR "Radio Red" Guadalajara @ 1,846 miles

 

[davideduardo]

WOAI had a similar experience - you can bet Austin listeners were important to them!

Why would Austin listeners be important to a San Antonio station? Austin and SA are two separate markets, and bought separately.

While there might be a couple of local accounts that appreciated the extended coverage, I really doubt that WOAI has been able to monetize out of SA listening for decades.

 

[1L6E6VHF]

... At night, as long as WLW uses the power vampire HD, I can barely hear it when I null KSEV. On the rare occasions when they turn off HD, they are much easier to hear by nulling KSEV. ...

I believe that AM broadcast stations radiate the same analog AM carrier power and analog AM modulation percentages when using HD as when they don't. The digital carriers do not occupy that same r-f spectrum, so they really shouldn't affect a good, analog-only AM receiver tuned to that analog center frequency.

Could you explain more about what you are experiencing?

That may be true if your radio is very high selectivity, or has a "brick wall" audio filter at 5KHz or lower.

If you listen on an AM receiver with less selectivity (i.e., a radio that could actually sound good on AM), you can hear a strong hiss on the program. If is bad enough on the car radio in a 2000 Grand Marquis, a GE Superadio, or an old Zenith TransOceanic. In a radio that is deliberately wide band, like the Sony SRF-A 100, the waterfall noise is almost deafening. In particular, if you listen in stereo mode (these radios would pass the phase information whether a station was stereo or not), you also hear a noise similar to a diesel motor running.

As for 700 in Southeast Michigan, WLW rules. I can't recall if I have ever logged anyone else on 700.

 

[boiseengineer]

Selective fading that causes the upper and lower sidebands to shift in phase will cause incursion of the HD sidebands into the analog greatly increasing the HD "noise". Here in Boise KFBK and KSL are both affected by this nightly. KFBK is unlistenable when the HD is on.
Or drive through a null of almost any Directional HD station.

(let me finish before hitting send this time)

In Boise

Day time:
A weak KALL Salt Lake City

Night:
KALL SLC UT
KGRV Winston OR (all 470 watts of it!)
Maybe KXLX WA (are they still on?)
WLW pops up on top regularly
Maybe KMBX Soledad CA guessing that's the SS I hear occasionally

 

[Icangelp]

SW Ohio

The Nation's Station. Morning, noon and nighttime too.

 

[Buckeyes2001]

Here is a very cool video on WLW and when they broadcasted with 500,000 watts and some neat history behind the station:

http://www.youtube.com/watch?v=CbHjcwIoTiY&fmt=18

 

[cyberdad]

Near north Chicago suburbs WLW day (weak), night (strong)

+1. Although here in the far northwest suburbs, WLW daytime is very weak and requires a very good radio in an open, noise free, area.

 

[charlestondxman]

In Charleston, nothing daytime. Never heard a signal there because of WOKV. Nighttime almost always WLW. Some nights it is weak, other nights it's as strong as some of the local AMs.

I've gotten WLW as far as the I-40/81 junction in East Tennessee during the day in summer. I've also heard it blast in Northern VA during twilight hours in the winter.