problem with some locals...

I have a CM 4228 HD mounted on my roof that is about 18' above ground.

I am getting all of the local UHF channels with no issues. Although, I am not getting my local CBS... I learned that they are VHF.

I attached my local radar map...

Anyone with a solution? I thank you in advance!

Yup, you'll need a small VHF high-band VHF antenna like an AntennaCraft Y5-7-13 or a Winegard YA-6713 (yes, they are back in production) and an antenna joiner like a Pico-Macom UVSJ to combinne the signals from the two antennas. Once connected, both PBS and CBS shuld come in fine. Aim the YA-1713 in hte same basic direction as your 4228.

The 4228 is average to mediocre on VHF, and your CBS station is not really strong, so it is understandable that you are having trouble with it.

Have you tried aiming the antenna right at ch 12?

8 and 12 are almost 180 degrees from each other and the way the 4228 gathers VHF (off the back screen) you would probably get both if you could get 12 (4228 is bi-directional on VHF).

If that does not work, try a VHF high antenna like the Winegard 1713 and join them wth a UVSJ (UHF/VHF signal joiner). That probably would only get you 12 and not 8 off the backside.

I somewhat disagree, even if I am not a fan of the 4228 antenna.

I think our OP, bw1969, is a prime candidate for for a good pre-amp or even a distribution amp that might lift that missing CBS above the digital cliff, especially if the coax run is fairly long.

But in such situations, theory is one thing, and the actual results are often what is the real bottom line test.

And I also have to wonder if an antenna rotor would yield dividends.

AMEN NonMctubber!

Sounds like you are preaching to the back row this morning.

I have a CM 4228 HD mounted on my roof that is about 18' above ground. Although, I am not getting my local CBS... I learned that they are VHF.

Anyone with a solution? I thank you in advance!

You may have FM interference. How far away from WVZA are you?

Try an attenuator, FM trap, or use an HLSJ to filter out FM.

Hi Tower Guy,

Where is there a source for FM traps? Rat shack used to have them but no longer... Also, how does an antennuator help with FM interference? I'm not familiar with using one in this application, so hopefully will something new today!
:)

Best,

Rick

Hi Tower Guy,

Where is there a source for FM traps? Rat shack used to have them but no longer... Also, how does an antennuator help with FM interference? I'm not familiar with using one in this application, so hopefully will something new today!
:)

Best,

Rick

Winegard FT-7600
http://www.solidsignal.com/pview.asp?p=FT-7600 You have to adjust it for minimum interference.

The FM trap in the AP-8700 preamp is also tunable.

If the FM station is extremely strong, it may overload the tuner so much that an attenuator will help.

In this case channel 12 has a noise margin of about 35 db and a signal level of -57 dbm. A 4228 should work for that signal if it's aimed properly. A 10 db attenuator should still have a noise margin of at least 25 db.

If you enter the same zip code in www.fmfool.com, the signal level of WVZA is -10 dbm at 2.5 miles away. With the zip code location uncertainty, that signal could range from +10 dbm at .25 miles to -16 dbm at 5 miles. WVZA is at 105.1 MHZ. The second harmonic would fall at 210.2 with modulation running from 210.0-210.4 MHZ. Channel 12 ranges from 204-210 mhz.

The problem could also be third order intermod between WVZA and WCIL. That would create a spurious signal at 206.6 MHZ.

:bowdown:Tower Guy is absolutely right, you know!

:bowdown:Tower Guy is absolutely right, you know!

No doubt, that's why I asked him! :)

ok... when they turned off the anolog signal is when I lost my CBS. So... I started checking and saw that originally the CBS was UHF. When it went all digital they jumped over to VHF. So, I deleted all my channels and unpluged my systems and did another channel scan and magically CBS is working again!

BUT... CBS goes in and out jumping from 80% signal strength to 0%. would a good amp be just what I need? If so, what would you recommend?

I am buying a rotor this weekend.

Thanks in advance for your help!!

I bought a RCA Bi-Directional RF Amplifier that is a 54-1000 Mhz performance and wow!!! Amazing results!! No drops and signal strength is amazing for all channels!!

My question now is; The RCA amplifier is a single output. Can I then split the signal to two televisions? Please advise.

Thank you!!

Yes, you can add a splitter to feed two tvs. Enjoy!

Yes, you can add a splitter to feed two tvs. Enjoy!
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Actually not so simple as IDrick paints it but damn near. You will probably need an additional short length of coax, one end screws into the output of the amp and then other end screws into the input end of the splitter. Then the two ends of the other cable runs screw into output ends of the splitter.

Either that or some gender changer that will allow the splitter to screw directly into the output end of the amp.

In short, you always have to worry about cable gender change issues, a male end will not screw into a male end, and a female end will not screw into another female end.

I too discovered it the hard way, here I had all those parts after I got some from the store, but they would not screw together.

I answered the "can I" question and NMT answerd the "how to" question. :)

for all having vhf problems with the 4228 that's made mainly for uhf. this is what i done for channel 11. had a old pair of rabbit ears. i broke off the diepoles and slide one on each side of the 4228 and then channel 11 come in perfect. it worth a try before you spend money on another antenna.

In short, you always have to worry about cable gender change issues, a male end will not screw into a male end, and a female end will not screw into another female end.

I guess you haven't seen the parade they put on in NYC!:lol:

i guess you haven't seen the parade they put on in nyc!:lol:

Funniest post in ages. Bravo!

ok... when they turned off the anolog signal is when I lost my CBS. So... I started checking and saw that originally the CBS was UHF. When it went all digital they jumped over to VHF. So, I deleted all my channels and unpluged my systems and did another channel scan and magically CBS is working again!

BUT... CBS goes in and out jumping from 80% signal strength to 0%. would a good amp be just what I need? If so, what would you recommend?

I am buying a rotor this weekend.

Thanks in advance for your help!!

Don't know if you're in the Albany, N.Y. area, but if you are and having issues with CBS 6, be advised the are also broadcasting CBS 6 on channel 45-3 in SD.