Whites Surf PI schematic

[Old cart]

I agree and sorry you no longer find it fun.

[Tim]

Yes, thanks Gary. All food for thought. Personally I appreciate your website, and input here. Sorry it is losing its lustre for you. I have had an extended hiatus from the sparks and smoke- sometimes that is all that is need for re-invigoration. Heading off to a permanent bush job in the new year and taking my electronics kit with me. I am going to try your "improved" BFO, with the oscillator substituted with Colin Mitchells circuit 8, as an appetiser.
The Surf sound sounds great to me, very clear and positive.

[homefire]

Yea, Much better. My hearing is messed up but I could deal with that.

[chemelec]

This might give you a better idea.

[homefire]

Good Stuff.

[chemelec]

Sorry, VERY CHEAP MICROPHONE.
Doesn't sound so high Pitch coming from the speaker.
And Loudness is Good.

[homefire]

Man I'd have to lower that freq. Hurts the Ears.

[chemelec]

Here is a Sound File, Recorded using an old Crystal Mic.
Excuse the Hum, not a very good setup.

[WM6]

The Only Other Surf I have seen with this transformer is one I also built and posted on here a few years ago.
But Didn't seem anyone was interested in it back than.

Wrong impress, your ideas and circuits solutions are very welcomed and really nice. Thank you.

[chemelec]

It Definitely gives better and louder sound and will drive a loudspeaker, although headphones are still best to use.

As to the Gain control I added, it is the same as shown in the Original Surf Pro Schematic by White's Electronics Inc.
I also included the frequency control of the 7660 from the 555.


The Only Other Surf I have seen with this transformer is one I also built and posted on here a few years ago.
But Didn't seem anyone was interested in it back than.

Personally I have no use for this Surf Detector, Just built it for fun and to see what difference it would make.
It goes in the garbage after in a few more days of playing with it.

Probably so will all my electronic parts and equipment in about 1 year.

[Old cart]

seems we say about different things. in YOUR schematic the shielding of pot GAIN is not needed.
i mean FEEDBACK RESISTOR ON FRONT END.

Perhaps that is the best place to adjust gain since it is essentially DC at that point. Trying to adjust the first stage gain with a pot is difficult as just a few pF of capacitance can are a difference. Maybe crank the first stage gain down to 500 and increased the D.C. Gain by a favor of 4 and then make it adjustable.
As for the transformer some versions of Surf PI had this very transformer. Does it really improve the sound? Can you make a recording?

[kt315]

[ATTACH]38246[/ATTACH] Here is my Schematic.

Replace the Feedback Resistor 1M on NE5534 to a Pot.

seems we say about different things. in YOUR schematic the shielding of pot GAIN is not needed.
i mean FEEDBACK RESISTOR ON FRONT END.

[chemelec]

Here is my Schematic.

[homefire]

I be thinking the Noise would only be a issue in a Hight RFI or EMI location. No one seems to Remember that you have to Match Impeadance with Head Phones and Speakers any more. It makes a wHOOPING difference in not only in Volume but Tones and Sounds. Thank You.

[chemelec]

Being Curious, I added in the Gain Control, using No Shielded wire and it added No Noise Problems.
I also found having the Gain control does seem to have some advantages in tuning this detector.
My detector also has a Audio Transformer to better match to speaker impedance.