100V Line Transformer identity?

[MikeCross]

I have a RS components line transformer that dates from the 60's
Its part number is 21-773-1

RS have deleted their cross reference database.

Can anyone please provide any information on this transformer.

I think it has two 8ohm secondary windings labelled A-B and C-D.

The primary has tags 1 2 3 4 5


Any help would be great.

[ValvoStef]

Hi Mike,

Does it look like those two?
Data sheet available from Electrocomponents, paer number R/N35A002F.

Hope this helps.

Stef.

[ValvoStef]

This is the link.

http://docs-europe.electrocomponents...6b80473a76.pdf

[Station X]

The OP refers to a "line" transformer. I wonder if he means a 100V line transformer or an output transformer?

[ValvoStef]

Originally Posted by Station X

The OP refers to a "line" transformer. I wonder if he means a 100V line transformer or an output transformer?

You are right, I have overlooked the 'line'. I have a couple of Tannoy PA speakers
with 100V transformers, they look very similar.

[MikeCross]

I have an RS Components line transformer with part number 21-773-1.
can anyone identify this part and provide details of the windings.

[MALC SCOTT]

A photo of the transformer would help.

[G8HQP Dave]

By 'line transformer' do you mean power transformer or line output transformer?

[Station X]

Or even 100 Volt Line Transformer?

[dazzlevision]

Hello,

Looking at my Radiospares catalogue for Aug-Nov 1970, there is a "100V line" matching transformer at 24/- (shillings!). This was before Radiospares became RS Components and adopted a part numbering system. The transformer has four primary taps to deliver l, 2, 5 or 10 Watts and the secondary has taps to feed 3 or 15 Ohm speakers: A B C & D.

If anyone has an early RS catalogue, I suspect this transformer will have the part number you mention.

Regards,

Dazzlevision

[MikeCross]

Thank you for all of your help.
It would appear to be the 100v matching transformer with a maximum output of 10 watts.

This is lower than what I require but I have now been given a Reslo 100v line transformer .
Part no LT202 which I hope may have a larger wattage tapping.

I have just repaired a Vortexion 50w amplifier and
basically I am looking for a 100v transformer that will provide 50watts into 8ohm
for a junior school project.

[Station X]

I've updated the title of this thread.

[Nicklyons2]

I may have transformer from a (quite new) scrapped PA amp; it is 'transistor output stage' to 4 Ohm-70V line-100V line. I'd assume the power amp circuit which fed it was 4-8 Ohm output impedance; looks 50 Watts-ish. Any use? if it is £5 + P&P and it's yours.

[Herald1360]

If HiFi isn't a requirement, an ordinary 115V + 115V to 12V + 12V mains transformer will do well enough. A 50VA one like this:

http://uk.rs-online.com/web/p/chassi...rmers/0504256/

Primaries in parallel, secondaries in series for ~ 100:20 volts.

[peter_sol]

Those 100v line amplifiers are not intended to just power 1 speaker as you are with say, 50 watts they are for use with several speakers each with their own transformer running at 10 watts max.

[MikeCross]

Does anyone recognise a Reslo 100v line transformer .Part no LT202.

It has two terminals on one side marked A B
On the other side are four screw terminals marked 1 2 3 4

[Station X]

Are you sure this is a 100V line transformer? Reslosound made microphone matching transformers with an LMT prefix.

[MikeCross]

I am told that this came out of a loudspeaker cabinet.
In actual fact I have been given two with the possibility of making two cabinets to get the required 50 watts.

I assume the A B terminals would be connected to the L/S and the 1234 provide the 100v tapping?

[Station X]

Originally Posted by MikeCross

I assume the A B terminals would be connected to the L/S and the 1234 provide the 100v tapping?

That sounds most likely. Usually the speaker side has connections for various speaker impedances and the line side has connections for various power levels.