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[m3vuv]

Hi,i have one of these units+ a download of the manual,can anyone explaine how the bal control works,or a good explanation on how its used?,i am trying to measure some 2.5mm stranded pvc covered wire on a drum to try and workout how much is left but failing to get a sensible reading,cheers Paul m3vuv.

[tubaman]

Never used one of these but have just taken a look at the manual (available here) and it seems the balance control is to allow you to take near-end measurements - ie when the fault is very close to where you are testing - and allows you to cancel out the transmitted pulse. For a long length of cable where you are trying to ascertain the distance to the disconnection point - ie the open end in the centre of the drum in this case - it appears you leave balance set to off.

[m3vuv]

cheers.it seems to have a bump at 18m,this is wrong,could do with a service manual so i can check it out,doubt one exists tho?.

[tubaman]

cheers.it seems to have a bump at 18m,this is wrong,could do with a service manual so i can check it out,doubt one exists tho?.

Probably a daft question but are you sure there's only one piece of cable on the drum?
The manual also says that it is calibrated for solid polythene insulator and that the lay of the cable may have an effect. However I doubt differences in either would give a measurement that is totally off beam.

[craigski]

Hi,i have one of these units+ a download of the manual,can anyone explaine how the bal control works,or a good explanation on how its used?,i am trying to measure some 2.5mm stranded pvc covered wire on a drum to try and workout how much is left but failing to get a sensible reading,cheers Paul m3vuv.

Cut off exactly 100mm, weigh the 100mm, then weigh the remainder. Should be able to calculate length. Then you can cross check with your TDR.

[m3vuv]

its more a case of learning how to use it,looked for videos to show ho to use but nothing found,will these test a single wire or do they have to be pairs?.

[underzone]

will these test a single wire or do they have to be pairs?.

The linked manual states: "The Tester 301C transmits pulses into a cable pair"

[m3vuv]

Probably a daft question but are you sure there's only one piece of cable on the drum?
The manual also says that it is calibrated for solid polythene insulator and that the lay of the cable may have an effect. However I doubt differences in either would give a measurement that is totally off beam.

the wire is in several pieces joined together,my issue is not knowing A how to use the bal properly and if the meter can only test a wire pair and not a single cable just containing a single conductor,could do with some info ie an old bt training document on the 301c,cant find anything except the manual for it,i find that too basic!.

[tubaman]

The BT301C was designed for telecoms networks so is for testing wires as pairs and I can't see how it's going to work if not used like that.

[m3vuv]

The BT301C was designed for telecoms networks so is for testing wires as pairs and I can't see how it's going to work if not used like that.

thats why i was asking,need someone who used to work with them,or knows them inside out.

[Black Sheep]

Hi mate.

Got your PM just now and also seen this thread.

Tubaman is correct I'm afraid, it can't operate measuring a single wire.

[m3vuv]

will they be ok for rg213 coax?,ie one connection to the coax screen+ the other too the coax center?.

[Black Sheep]

will they be ok for rg213 coax?,ie one connection to the coax screen+ the other too the coax center?.

Hmmmm - good question, mate ??

Not something I've ever tried in my job, as we work with twisted pair cables. You've now got me intrigued, could you let me know if it does work, please ??

[m3vuv]

will do,can you explain what the bal pot is for so i can set it up to try on coax,the manual is as clear as mud about using the balance control,cheers + 73 de m3vuv.

[m3vuv]

if it does work for coax it will be handy to take to radio rallys to see how much coax is on a drum,i dont suppose they test for loss,any ideas anyone of the test frequency and voltage,just dont fancy frieing my scopes front end trying to take measurements of the 301 outputs.