surf PI mod

[dom44]

I have built the surf PI and its a great detector but might be me old age but i found the Volume a bit lacking so experimented and came up with a simple mod that gave me double the Volume, have to turn it down now.


and for you do it yourself headphone fans like me a good source of piezo transducers is old smoke detectors and they are good size to.

[chemelec]

This Mod will give you Very Good Volume on headphones or even a small speaker.

[taliesin]

I have built the surf PI and its a great detector but might be me old age but i found the Volume a bit lacking so experimented and came up with a simple mod that gave me double the Volume, have to turn it down now.


and for you do it yourself headphone fans like me a good source of piezo transducers is old smoke detectors and they are good size to.

could you put a picture of you homemade phones up ?i'd like to have a look.
thanks

[Vortxrex]

Hi Gary, what is the turns ratio on the transformer ?

Dave Frank

[chemelec]

Hi Gary, what is the turns ratio on the transformer ?

Dave Frank

It is a Minature Audio Transformer, worth about $3.00 from Mouser or me.

500 Ohm to 16 Ohm Impedance.
43 Ohm DC Primary Resistance
16 Ohms DC Secondary Resistance
Turns Ratio = 5.6 : 1

[dom44]

Here ya go my smoke detector headphones work great to

[taliesin]

nice job.might have a go myself .cheers

[douglas]

I turned p the volume by changing R34 from 150 ohm to one ohm.