RG58 cable trimmer

[Deathwish]

I have a couple of RG58 cables to interconnect my Sig Gen and other stuff to each other, I want to plug it into my scope as well, problem is it needs a trimmer , anyone know where to get one or make one ?.

[apis]

What do you mean by trimmer?

[tron9000]

http://uk.farnell.com/webapp/wcs/stores/servlet/Search?st=RG58&catalogId=15001&categoryId=700000006706&langId=44&storeId=10151

These?

[miguelvp]

Maybe you are referring to a terminator, like a 50 ohm one?

[Deathwish]

No. the same as is on my scope leads to trim them

[ElektroQuark]

The variable capacitor od probes?
You don't need that.

[Deathwish]

Why not ?. the waveform coming from my sig gen into my scope on a rg58 lead is sloping like hell.

[apis]

Is the scope input 50 ohm terminated?

[BravoV]

I guess the OP means the 50 Ohm terminator, here, a picture worth thousands of words ...

[Deathwish]

ahh ha so I need to get a 50Ohm terminator then , thanks.

[apis]

The terminator is just a 50 ohm resistor to ground (ie from inner conductor to the shield) I believe, so you might be able to make something yourself.

[tomlut]

Make sure your sig gen is set to have a 50 Ohm output impedance as well.

[Deathwish]

The terminator is just a 50 ohm resistor to ground (ie from inner conductor to the shield) I believe, so you might be able to make something yourself.

Beats £1.50 for one then. will give it a go later.

[Deathwish]

Make sure your sig gen is set to have a 50 Ohm output impedance as well.

It does. Thanks.

[BravoV]

Make sure your sig gen is set to have a 50 Ohm output impedance as well.

Maybe this sounds trivial, and also unlikely looking at OP's experience, but I mention it here anyway, make sure the scope's input is NOT set to 50 Ohm mode.

Most low end scope don't have 50 Ohm mode input, and if it does, then you don't need the terminator.

[apis]

There will still be losses in a coax cable especially for high frequencies and longer cable but if you don't terminate it properly the signal bounces when it hits the end of the cable. The reflected signal adds up (superimpose) with the original on the way back and then goes into the signal generator, so you can get very strange results.

[Deathwish]

My scope is a tek 2225 thank you    , soon to be a rigol 1054z today, I hope, if it comes.

[miguelvp]

My scope is a tek 2235 thank you    , soon to be a rigol 1054z today, I hope, if it comes.

You'll still need a 50 Ohm terminator for the Rigol. The DS2000 has a 50 Ohm terminator built in but only accessible via an SCPI command which is a pain because you'll have to reset it back and there is no UI for it within the scope's menu. So your best bet is to get the T connector and the terminator, or a through terminator (more expensive)

[Deathwish]

I have 3 tee connectors, I used to repair TV's many many years ago.  I have never had the desire to leave any kit permanently connected to a scope so was unsure if it should be trimmed.

[BravoV]

I have 3 tee connectors, I used to repair TV's many many years ago.  I have never had the desire to leave any kit permanently connected to a scope so was unsure if it should be trimmed .... terminated .

.... correction ... , the source of confusion to all of us here.

[apis]

https://www.eevblog.com/forum/projects/home-made-feed-through-terminator-for-bnc/

[Deathwish]

I have 3 tee connectors, I used to repair TV's many many years ago.  I have never had the desire to leave any kit permanently connected to a scope so was unsure if it should be trimmed .... terminated .

.... correction ... , the source of confusion to all of us here.

slap accepted. Sorry

[BravoV]

I have 3 tee connectors, I used to repair TV's many many years ago.  I have never had the desire to leave any kit permanently connected to a scope so was unsure if it should be trimmed .... terminated .

.... correction ... , the source of confusion to all of us here.

slap accepted. Sorry

Its ok, it happened to all of us sometimes. 

When I first read that word "trim", I have this in my mind .... 

[tautech]

I have a couple of RG58 cables to interconnect my Sig Gen and other stuff to each other, I want to plug it into my scope as well, problem is it needs a trimmer , anyone know where to get one or make one ?.

Proper termination is discussed in the first page of this thread:
https://www.eevblog.com/forum/testgear/show-us-your-square-wave/

[Deathwish]

I'm getting old, leave me alone  , actually I kept asking people here for a small filing cabinet, they kept bringing me them and i kept saying nope wrong thing, turns out I was looking for a bisely drawer set.... Then blast my eyes if no sooner than I order one for my bits Toploser  starts to sell a decent set of drawers on wheels