Using Sony BVM-1915 without BNC terminators.

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tisurame
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Using Sony BVM-1915 without BNC terminators.

Post by tisurame »

I'm using a Sony BVM-1915 (manufactured in 1990) for almost 2 years and I just found out that it's recommended to use BNC terminators for connectors that are not used. Considering that I have been using this monitor for so much time without any apparent problem, do I really needed to use BNC terminators? Did I risk to damage the monitor for not using these terminators?

Since they are cheap, I might buy a few BNC terminators. But first I would like to know how many I would need. This is a picture of the back of the monitor, with my current configuration.

Image

Thanks!
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Fudoh
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Re: Using Sony BVM-1915 without BNC terminators.

Post by Fudoh »

some monitors have auto termination. You certainly don't need them. If your monitor is supposed to be used with terminators and you're not using any, you usually end up with out of spec black and white levels.
tisurame
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Re: Using Sony BVM-1915 without BNC terminators.

Post by tisurame »

Fudoh wrote:some monitors have auto termination. You certainly don't need them. If your monitor is supposed to be used with terminators and you're not using any, you usually end up with out of spec black and white levels.
Thanks. I don't have the manual, but reading the manual of the BVM-1916 (link), which seems very similar to my BVM-1915, on page 10 it says "when the loop-through output is not used, attach a 75-ohm terminator". I also have read somewhere that only PVM have auto termination, but not the BVM.

Anyway, thanks for the enlightenment. I just wanted to be safe.

Btw, my monitor seems to have a dual input for RGB and Component, but whenever I connect two devices, using both inputs, one will create interference with the other. For example, if I connect a PS2 and Wii console, one using each component input (above and below), and if I want to use the PS2, I thought I would only need to keep the Wii turned off. But in order to avoid some annoying interference while playing the PS2 (or vice-versa), I need to detach the video cable from Wii (from the console itself). Is there a easier way to use both inputs, without the need to detach the cable from the unused console (in order to avoid interference)?
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Fudoh
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Re: Using Sony BVM-1915 without BNC terminators.

Post by Fudoh »

Is there a easier way to use both inputs, without the need to detach the cable from the unused console (in order to avoid interference)?
maybe that's gone with adding termination plugs, so try that first.
tisurame
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Re: Using Sony BVM-1915 without BNC terminators.

Post by tisurame »

Fudoh wrote:
Is there a easier way to use both inputs, without the need to detach the cable from the unused console (in order to avoid interference)?
maybe that's gone with adding termination plugs, so try that first.
So, do you know how many BNC terminations I would need?

I was watching this review of a BVM-1911 (https://www.youtube.com/watch?v=TImL_UqSz8E) and one user commented "You definitely need 75ohm BNC terminators on all the outputs on BVM sets. You could be potentially damaging your set without using terminators on all outputs".

So, I was wondering if I really only need 3 BNC plugs for the output connectors, or also the input connectors....
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Fudoh
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Re: Using Sony BVM-1915 without BNC terminators.

Post by Fudoh »

oh, sorry - now I got you. Your monitor does NOT have dual inputs. Each of the inputs has a loop output (the upper one is the input, the lower one the output) and you have to put terminators on all four. On your sync line you're supposed to use the upper one as well and terminate the lower one.
tisurame
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Re: Using Sony BVM-1915 without BNC terminators.

Post by tisurame »

Fudoh wrote:oh, sorry - now I got you. Your monitor does NOT have dual inputs. Each of the inputs has a loop output (the upper one is the input, the lower one the output) and you have to put terminators on all four. On your sync line you're supposed to use the upper one as well and terminate the lower one.
So, what about the Output on the right and the input on the left (see the picture on the first post), do I also need to use a terminator on them?

I wonder why it always worked for me without any terminator plug.
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Fudoh
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Re: Using Sony BVM-1915 without BNC terminators.

Post by Fudoh »

inputs on the left are composite video inputs (and loop outputs). Decoder output on the right is likely a YUV output from composite sources.
wonder why it always worked for me without any terminator plug.
as said, it always works. You just likely will get slightly different brightness offsets once you use some.
tisurame
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Re: Using Sony BVM-1915 without BNC terminators.

Post by tisurame »

Fudoh wrote:inputs on the left are composite video inputs (and loop outputs). Decoder output on the right is likely a YUV output from composite sources.
wonder why it always worked for me without any terminator plug.
as said, it always works. You just likely will get slightly different brightness offsets once you use some.
So, I do not need to use terminators on the composite video and the decoder output. OK.

It seems it works without it, but I will buy these terminators anyway, just to be safe. Is there any true about damaging the monitor if you are not using it? My brightness control is on the half. And as I said, I'm using this monitor for almost 2 years.

About using more than one device with this monitor, is there any cheap and easy way to do it? It looks like a device like a Extron Switch would work, but I would not be able to find it in my country.
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Fudoh
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Re: Using Sony BVM-1915 without BNC terminators.

Post by Fudoh »

About using more than one device with this monitor, is there any cheap and easy way to do it?
easiest way is a scart switch. Just connect your adapter cable to the output of the switch (you might need a coupler) and your systems to its inputs. You can usually route both RGB and component this way.
Is there any true about damaging the monitor if you are not using it?
no.
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fact
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Re: Using Sony BVM-1915 without BNC terminators.

Post by fact »

Glad I read this thread, just got a bvm-d20f1u and the manual does indeed say to use 75 ohm terminators on unused inputs. But I wasn't sure if this was because it could cause interference, guess we know its the later now. either way it's probably a good idea to have them on any output you aren't using, incase you decide to use the input on various option cards you might have. so the question is, where is the best place to pick up bnc terminators? they seem pretty pricey sold as singles.
>:D
tisurame
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Re: Using Sony BVM-1915 without BNC terminators.

Post by tisurame »

I was wrong when I used the term "interference" when I tried to connect two consoles at the same time using the input and loop-through output. Actually, the picture was just very dark and dim.

Then, today I bought four BNC terminators (pretty pricey indeed) to use with the loop-through outputs - since I'm using only one device connected to the monitor. To my surprise, this same thing happens: a very dark and dim picture. It seems the contrast is way too low.

So, using BNC terminators produces a picture with a VERY low contrast. To correct this problem, I need to increase my contrast from 50% (without BNC terminators) to almost 100% (with BNC terminators).

Curiously, I have a small CRT PC monitor with a default contrast setting of 100%. I also have a Sony Wega consumer TV which the "normal" settings is using the contrast at 80% and the "brilliant" and "sports" settings use the contrast at 100%. Now it seems a bit odd that my BVM is able to produce high contrast using only 50% (without the BNC connector).

What's going on? Should I use the terminators with my contrast at 100% or remove the terminators and use my contrast at 50%, like I was always doing before?
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