Engineering questions about WMGM-DT (TV)

[JerseyShor]

I have an outdoor antenna (Antennas Direct DB4) and get pretty solid reception of WMGM-DT, however, I have some "issues".

1) On one of my OTA receivers (a DirecTV H20 with built in OTA tuner) I get no audio at all. Hooked directly to the TV and another type of DirecTV receiver the sound is fine. Any ideas why this may be?

2) The picture on this channel seems "cropped". Like the very top and very bottom of the picture are being cut off. This is both connected to the DirecTV tuners and directly connected to the TVs. Any ideas here?

3) Is WMGM-DT operating at full or reduced power? I remember them having problems with WZXL?

I get a watchable signal about 90% of the time but do get some drop outs, especially in bad weather. My usual signal strength is in the mid 40s to low 50s on the DirecTV receivers and the lower 40s when directly fed to the TVs. (At about 40-45 miles from the tower I guess this is to be expected)

 

[tom]

Let me preface this by saying that I don't watch TV at all,
except for some TIVO'd stuff from DirecTV (no commercial TV)

I hooked up my HD TV to a piece of coax and a clip lead
and tried off the air for the first time ever (the set is a few years old)

I scanned and it got three channels ... WNJS, WMGM and WMCN ??

WMGM-TV is definitely too big vertically with the top and bottom being clipped off.

I have no idea why your sound is off on your one tuner, maybe it's set to SAP ?

I know that WMGM-TV is in the middle of a total plant rebuild $$$, so the picture
you see now may be a temporary setup while they are working on it.

I do know for a fact that they are operating at full power, I have seen
the output meter right on "100%" in the last few weeks when I was
doing things at WZXL.

I have no idea what WZXL would have to do with anything, other than being on the
same tower, there is no connection. Shared tower users do have to reduce power
for the safety of workers on the tower, but nothing has been done for a long time.

Anyway - I'm not impressed by OTA DTV ... I don't think the clip lead will
be replaced with an antenna, I'll stick with DirecTV. (not HD tuners)

 

[JerseyShor]

I have no idea what WZXL would have to do with anything, other than being on the
same tower, there is no connection. Shared tower users do have to reduce power
for the safety of workers on the tower, but nothing has been done for a long time.

There was an STA for WMGM-DT due to not having enough room on the tower for all the WMGM-DT bays due to the WZXL antennas.

The STA says, in part:

The attached Engineering Statement of Joseph M. Davis, P.E., of Cavell, Mertz & Davis, Inc., explains in detail the extraordinary circumstances that warrant temporary operation at variance from the Commission’s rules. Mr. Davis explains that the WMGMDT, Channel 36, antenna has replaced the WMGM-TV, Channel 40, antenna as the topmounted antenna on its tower. When the attempt was made to place the new WMGMTV, Channel 40, side-mounted antenna on the tower, the 24-bays of the new antenna were too large to fit on the tower, because of the existing WZXL(FM), Ch. 264B antenna. Therefore, the WMGM-TV, Channel 40 antenna had to be reduced from a 24-bay antenna to a 16-bay antenna.
The reduced number of bays on the WMGM-TV antenna reduced the gain provided by the antenna, such that the maximum ERP achievable is 569 kW at 116 meters. This results in an ERP less than the 955 kW at 112 meters authorized in the construction permit, and less than the 741 kW at 128 meters ERP of the licensed facility. Therefore, the instant request for temporary authority is necessary.

See: https://licensing.fcc.gov/cdbs/CDBS...?appn=101164239&qnum=5420&copynum=1&exhcnum=2

 

[tom]

What you posted says that the new DTV antenna went on top of the tower where
the original Channel 40 (Analog) antenna was. The analog antenna was moved down
to be a temporary side mount, and it was too big, so they took some bays off and
operated Channel 40 (Analog) at reduced power.

The digital channel wasn't affected by that.

Many stations went through similar issues due to space constraints.

It's kind of sad to see the fairly new Channel 40 analog transmitter sitting off and cold.
It was a beautiful installation only a few years ago.

 

[NeilRattigan]

Tom...by total plant rebuild, do you mean they will go HD on their newscasts?

I can now watch them on DirecTV, and it' still 4x3.

BTW, are they showing the NBC signal in HD?

 

[MickeyD]

Let me preface this by saying that I don't watch TV at all,
except for some TIVO'd stuff from DirecTV (no commercial TV)

I hooked up my HD TV to a piece of coax and a clip lead
and tried off the air for the first time ever (the set is a few years old)

I scanned and it got three channels ... WNJS, WMGM and WMCN ??

WMGM-TV is definitely too big vertically with the top and bottom being clipped off.

I have no idea why your sound is off on your one tuner, maybe it's set to SAP ?

I know that WMGM-TV is in the middle of a total plant rebuild $$$, so the picture
you see now may be a temporary setup while they are working on it.

I do know for a fact that they are operating at full power, I have seen
the output meter right on "100%" in the last few weeks when I was
doing things at WZXL.

I have no idea what WZXL would have to do with anything, other than being on the
same tower, there is no connection. Shared tower users do have to reduce power
for the safety of workers on the tower, but nothing has been done for a long time.

Anyway - I'm not impressed by OTA DTV ... I don't think the clip lead will
be replaced with an antenna, I'll stick with DirecTV. (not HD tuners)

I am not surprised that you are not impressed with the OTA signal. The US adopted an inferior transmission system, 8-VSB vs COFDM, that everyone else uses world wide.

I'm not the least bit surprised that the FCC wants to take all OTA TV off the air and put it on cable and satellite and give the BW to 3 and 4G companies.