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WTMJ Ch 4 signal weak and fluctuating?

Started by beeper, Tuesday Jul 07, 2009, 09:27:53 AM

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beeper

I visited a relative in Elkhart Lake over the Fourth and they complained that Ch 4 has been untunable or a weak signal recently.

Before the transition, there wasn't ever a problem receiving Ch 4 since it had a good and steady signal.

Now if it is tunable, the signal is borderline and the picture breaks up.
Then momentarily, the signal is back up to were it normally had been.

No problem with any other Milwaukee or Green Bay station signals.

techguy1975

CH4's digital transmitter took a direct lightning hit back on 6/19.  They were off the air for a couple hours, came back on at half power later in the morning, and I believe were back up to full power within a day or so.  But, from what I heard its still been a little unstable.  It could be something related to that..  I haven't heard any updates though, so I'm not sure if they got all the problems corrected or not

AA9VI

yes, it is definitely weaker than it was a few months ago before the strike.

jspear

I have not been able to receive a signal from channel 4 (4.1) since the change to digital.  I am on the 2400 block of Palmer, I believe that puts me just over a mile away from the transmitter (antenna).

Any suggestions?

Thanks,

_-Jo

John L

Quote from: jspear;52973I have not been able to receive a signal from channel 4 (4.1) since the change to digital.  I am on the 2400 block of Palmer, I believe that puts me just over a mile away from the transmitter (antenna).

Any suggestions?

Thanks,

_-Jo

Do you get other channels on your DTV box or TV?   You should do a re-scan, even if you already did once.

 Its also possible their DTV transmitter is off the air as I type this. I am at work, so I wouldn't know.

-John L.

jspear

John, thanks for the response.  I get other channels, just no 4 and 6.  I have done rescans and programmed the number in directly.  The TV I am using is Digital so no converter box.

John L

Quote from: jspear;52983John, thanks for the response.  I get other channels, just no 4 and 6.  I have done rescans and programmed the number in directly.  The TV I am using is Digital so no converter box.

You must be getting some interferences on UHF channels 28 and 33 preventing you from receiving 4 and 6 respectfully.  When you are close to the TV towers images can appear in odd places across the band.   Especially ch. 6's digital signal is smack right next to ch. 12's. But ch. 12 is smack right between ch. 6 and ch. 36.
But with the signals next door shouldn't matter. It could be the signals over powering the tuner a bit which can cause images.  

Not sure if Radio Shack still has them, but a device to decrease signal strength going into the RF input 75 ohm connection.  I think the device was called a "RF attenuator".

-John L.

jspear

John,

That might be just the ticket, my antennae is home made, enjoyed calcing the spacing on my own.  However, the RF is old and off an old vcr; it could very well be in poor enough shape that it is not receiving possibly.  

I will purchase a new one and swap it out.  Thank you again.

_-Jo

PatM

Quote from: beeper;52712I visited a relative in Elkhart Lake over the Fourth and they complained that Ch 4 has been untunable or a weak signal recently.

Before the transition, there wasn't ever a problem receiving Ch 4 since it had a good and steady signal.

Now if it is tunable, the signal is borderline and the picture breaks up.
Then momentarily, the signal is back up to were it normally had been.

No problem with any other Milwaukee or Green Bay station signals.

For the last week I have been experiencing the same problem.

I have a rooftop antenna which is correctly oriented.
I'm located in Wauwatosa near 124th & Watertown Plank Rd.

All of the other channels in Milwaukee come in strong.

I never had a problem with 4 prior to this.
Rescanning did not help - in fact I had to rescan twice as the station was not recognized the first time.

Nels Harvey

I too am noticing a degradation of the WTMJ signal.  I have a CM 4228 antenna only about six miles north of the station.  I recently added another digital receiver replacing an old analog TV that was on my little network in the home.

All of the other stations come in perfectly, but I'm getting breakups from Ch. 4.  I placed a signal meter on the line feeding that TV, and found a strong signal level comparable to, or higher than,  the other area stations.

As I've pointed out in the past, the 'signal reading' found on many TV's is a measure of signal quality, or 'Figure of Merit'.  It is more comprehensive than a simple measurement of RF level.  Variations could include multipath, encoding error, or other problems.

Therefore I must conclude that there is either a problem with components other than signal strength, or during the times when I experience the breakups, there IS a drop in signal levels.  I will compare today's signal level readings to if, or when, I see the problem, and tell you what I find.
Nels....
Retired TV Engineer
Resident, State of Mequon
Sharp 70" LCD, E* VIP 612 HD DVR,
40" Sony LCD, E* VIP 722K HD DVR.

Northern Fringe

Up here in Oshkosh, I have a difficult time receiving WTMJ.  When the other Milwaukee stations are coming in (except WBME), WTMJ will either be breaking up or just not be there at all.  It takes good conditions to be able to receive a stable signal.  I have a very good antenna system and amplifier (91XG & CM-7777), but for some reason their signal has never carried well up here.

AA9VI

Quote from: Northern Fringe;53903Up here in Oshkosh, I have a difficult time receiving WTMJ.  When the other Milwaukee stations are coming in (except WBME), WTMJ will either be breaking up or just not be there at all.  It takes good conditions to be able to receive a stable signal.  I have a very good antenna system and amplifier (91XG & CM-7777), but for some reason their signal has never carried well up here.

WTMJ has one of the lowest of the antenna heights above ground of the major stations. Their DT antenna is not at the top of the tower either, their analog one is, I believe. Surprised WISN isn't giving you more trouble.

HAAT= height above average terrain, 3.28 m= 1 ft

Station      HAAT (m)
WISN         263.1
WTMJ         272.6
WVTV         302
WITI          304
WDJT         322
WCGV        340.3
WMVS        353.8
WMVT        354.9
WPXE        358


Nels Harvey

Quote from: Nels Harvey;53897I too am noticing a degradation of the WTMJ signal.  I have a CM 4228 antenna only about six miles north of the station.  I recently added another digital receiver replacing an old analog TV that was on my little network in the home.

All of the other stations come in perfectly, but I'm getting breakups from Ch. 4.  I placed a signal meter on the line feeding that TV, and found a strong signal level comparable to, or higher than,  the other area stations.

As I've pointed out in the past, the 'signal reading' found on many TV's is a measure of signal quality, or 'Figure of Merit'.  It is more comprehensive than a simple measurement of RF level.  Variations could include multipath, encoding error, or other problems.

Therefore I must conclude that there is either a problem with components other than signal strength, or during the times when I experience the breakups, there IS a drop in signal levels.  I will compare today's signal level readings to if, or when, I see the problem, and tell you what I find.

After writing the above, I did some experimentation.  I put a 12db attenuator in line with the problem TV.  Ch. 4 (28) cleared up and now plays very well.  The other local stations also play just fine.  What I think has occurred is the signal levels of whatever was interfering with the Ch. 4 reception were reduced to a point below the threshold of interference.

I have pointed out before that the signal reading found on most new TV's is only a figure of merit.  In my case, dropping the input level actually increased the signal quality.  There are many aspects that affect digital TV reception.  In my case attenuation of the strong signals from my CM 4228 antenna cleared up the problem I was experiencing.

Nels....
Nels....
Retired TV Engineer
Resident, State of Mequon
Sharp 70" LCD, E* VIP 612 HD DVR,
40" Sony LCD, E* VIP 722K HD DVR.

AA9VI

I noticed it coming in a bit better lately.  Wonder if they've done anything.  It's actually better than WITI now.  (I get co-channel interference with WITI from WCHU-LD on UHF 33).