Can I have the best of both worlds, F-Type connection and wireless?

[obsolete man]

Hey Guys, so in my home... against a display shelf/wall. I have many vintage tvs. I've managed to wire many of them to a bunch of bonder tongue mini agile modulators.

So here's my set-up..

1. Six agile modulators all go into a combiner.
2. The combiner then outputs to a 10-way splitter.
3. From here, we f-type coaxial directly to various tvs. These tvs receive perfect reception. This allows me to change to six channels all with different shows.
4. One of the output on this splitter is connected to an antenna for tvs that cannot get a direct connection.

I realize with this set-up the antenna as a transmitter is TERRIBLE. I found out that for the antenna to work its best as a transmitter, it needs to be connected to the agile modulator directly. But then there would only be one source airing wirelessly. I also connected the antenna to the output of the combiner to see if that would improve, and if it did, then I would remove the splitter and just have all tvs go wireless. However, even when putting antenna at the combiner, it was no good. Nothing I did compared to connecting the antenna directly to a modulator.

Is this limitation a fact of life for this hobby, or is it because I'm a newbie and don't know of better methods? If there is a way for me to get the best of both worlds. Please school me. Thank you for your time.

[old_tv_nut]

Some one who has done this will chime in with a better answer, I'm sure, but I have a few questions that may help think aobut this:

1) Is the combiner lossless as used?
3) what channels are you using?
3) for wireless, what kind of receiving antennas are you using?

[obsolete man]

Originally Posted by old_tv_nut

Some one who has done this will chime in with a better answer, I'm sure, but I have a few questions that may help think aobut this:

1) Is the combiner lossless as used?
3) what channels are you using?
3) for wireless, what kind of receiving antennas are you using?

1. Drake PC1601 Passive Combiner. I'm not sure if that means lossless?
2. The usual VHF 2,3,4,5,7,9,11,13
3. For transmitting, it's a cheap RCA has two dipoles and the middle is a round UHF. For receiving, it's whatever built in antenna the tv has.

[old_tv_nut]

My first guess is you would get better results with UHF and dedicated UHF antennas for transmitting and receiving, but I suppose you have some VHF only receivers. In that case, I would expect the upper VHF channels to work better. Are you seeing differences due to channel number? Have you tried adjusting the length of the dipoles?

There have been discussions here on what kind of antenna to use to transmit - give it a search.

Combiner manual says 17 dB insertion loss, so you need a 17 dB amplifier following it to get back to the modulator output level. It also needs to be able to handle the desired signal level without crossmodulation, so you need a 20 dB gain distribution amp designed for the high signal level input; a 20 dB antenna distribution preamp may have problems.

Manual:
https://cdn-docs.av-iq.com/other/PC1601_Datasheet.pdf

[old_tv_nut]

Let me repeat, I'm starting at ground zero of knowing the best way to do this, hope someone else chimes in.

[obsolete man]

Originally Posted by old_tv_nut

My first guess is you would get better results with UHF and dedicated UHF antennas for transmitting and receiving, but I suppose you have some VHF only receivers. In that case, I would expect the upper VHF channels to work better. Are you seeing differences due to channel number? Have you tried adjusting the length of the dipoles?

There have been discussions here on what kind of antenna to use to transmit - give it a search.

Combiner manual says 17 dB insertion loss, so you need a 17 dB amplifier following it to get back to the modulator output level. It also needs to be able to handle the desired signal level without crossmodulation, so you need a 20 dB gain distribution amp designed for the high signal level input; a 20 dB antenna distribution preamp may have problems.

Manual:
https://cdn-docs.av-iq.com/other/PC1601_Datasheet.pdf

I found a boost from a leaf antenna that I'm not using. From the combiner, I output to this boost, then this boost goes into the splitter. The antenna that's attached to this splitter works better now. However, I get these ghost bars going from left to right. If it only happens on the wireless sets, that would be okay, but now all the tvs with the direct connection are getting this left to right scrolling bars too.

But I went back to my original set-up without the boost, and I started modulating to some UHF channels, and the wireless reception did work better for some of these UHF channels. But still, not the same quality as direct connect. BTW, when I'm doing these testings, the antenna and the wireless sets are in the same room, maybe just a foot away, and I still can't achieve a clear picture like I would with a direct connect.

[luRaichu]

By "boost" I think you mean one of those cheap antenna amps designed for RX setups? Wouldn't trust those but I don't know anything that would work better with that kind of bandwidth in mind & for a reasonable price.
I've never heard of anyone airing 6 channels at once for a home setup. Maybe, you will need 6 RF amps before the combiner stage?

[old_tv_nut]

Originally Posted by obsolete man

I found a boost from a leaf antenna that I'm not using. From the combiner, I output to this boost, then this boost goes into the splitter. The antenna that's attached to this splitter works better now. However, I get these ghost bars going from left to right. ...

This is cross-modulation, what you would expect from using an ampifier meant for weak antenna signal levels to amplify a group of higher level signals. You need a cable-system amplifier designed to work at high levels.

[luRaichu]

Originally Posted by old_tv_nut

You need a cable-system amplifier designed to work at high levels.

Aren't we dealing with broadcast frequencies here

[old_tv_nut]

Originally Posted by luRaichu

Aren't we dealing with broadcast frequencies here

Cable frequencies include broadcast frequencies.

[obsolete man]

Originally Posted by old_tv_nut

This is cross-modulation, what you would expect from using an ampifier meant for weak antenna signal levels to amplify a group of higher level signals. You need a cable-system amplifier designed to work at high levels.

What would be more ideal, putting an amp before the combiner or after? If before, then I would need to find an amp combiner? Is there such a thing? LOL!

What are cable system amps? Like any old school blonder tongue amplifier? I searched ebay for Blonder Tongue Amps and most are just one in, one out. Can you tell me which of these search results fits my need?

https://www.ebay.com/sch/i.html?_fro...ifier&_sacat=0

[old_tv_nut]

The BLONDER TONGUE BIDA BROADBAND DISTRIBUTION AMPLIFIER 750-30
manual says it's designed for cable-drop input, sounds like the right input level to me, although it doesn't say what signal level exactly.

https://www.manua.ls/blonder-tongue/bida-750-30/manual

The BIDA 550-50 would privide a stronger output, IF it doesn't overload. I would be tempted to try this one first and hope that if it overloads it can be adjusted out with the attenuator, or even by adding an external attenuator if necessary.

[Electronic M]

I run 4 channels of wireless agile modulator simultaneously could easily do 5-8, but I would need to build more programming sources to make that worthwhile (there really isn't anything I care to watch over the air locally).

Using a single transmit antenna or an off the shelf antenna to transmit isn't a good idea IMO. I use 4 separate home made half-wave dipoles made from a F-type connector and lamp Cord for VHF.

What I would do if I was in your shoes is set up 6 transmit antennas directly connected to their respective modulators, remove the combiner from the system completely, hook the input of the splitter to a variable gain antenna preamp and a receive antenna placed fairly close to the transmitter antennas then adjust the position of the antenna and amp gain to duplicate the wired system performance.

You're going to have a much harder time trying to get good transmitters if you split output between wired and wireless systems or try to use a single transmit antenna, and also leave the system more open to systemic failure.

I've explained my antenna system so many times on videokarma that my sore fingers want you to look one of those up so I don't have to write it again.

[obsolete man]

Originally Posted by old_tv_nut

This is cross-modulation, what you would expect from using an ampifier meant for weak antenna signal levels to amplify a group of higher level signals. You need a cable-system amplifier designed to work at high levels.

Good news! I just realized something... since my wired pictures are fine, I did not need to put the boost between splitter and combiner, which was causing this cross-modulation even with the wired picture.

I just tried placing the boost between the antenna and one of the outputs on the splitter. But doing this, the boost needed to be used backwards by using a f-type coupler. Wireless reception is much better now with some ghost bars, depending on channel, it can go up and down or left and right, but the picture is clear. And this time, the wired tvs are not effected, they are still crystal clear.

I'm still going to buy some of those blonder tongue amps, just to see how all this looks with better equipment.

[obsolete man]

Originally Posted by Electronic M

I run 4 channels of wireless agile modulator simultaneously could easily do 5-8, but I would need to build more programming sources to make that worthwhile (there really isn't anything I care to watch over the air locally).

Using a single transmit antenna or an off the shelf antenna to transmit isn't a good idea IMO. I use 4 separate home made half-wave dipoles made from a F-type connector and lamp Cord for VHF.

What I would do if I was in your shoes is set up 6 transmit antennas directly connected to their respective modulators, remove the combiner from the system completely, hook the input of the splitter to a variable gain antenna preamp and a receive antenna placed fairly close to the transmitter antennas then adjust the position of the antenna and amp gain to duplicate the wired system performance.

You're going to have a much harder time trying to get good transmitters if you split output between wired and wireless systems or try to use a single transmit antenna, and also leave the system more open to systemic failure.

I've explained my antenna system so many times on videokarma that my sore fingers want you to look one of those up so I don't have to write it again.

Okay, thank you! I will trial and error all methods. LOL! But today, I've discovered how to improve the wireless reception by placing boost between antenna and the output of the spitter. Picture is better but has ghost bars. Do you experience any of these ghost bars with your set-up?