Tuesday, April 9, 2019

turret board or pin board options. Direct conversion receiver.

Perf board is good. What if you have none?
My new go to amp on perf board.
Peg board for DBM.
A piece of wire and a pair of pliers to make turrets.
Smash the end and cut it .
By drilling a hole to fit the round part and inserting it you make a turret board or pin board. The flat being larger prevents its going thru.

This amp uses some of the pins. With a 1300:8 transformer it drive a small speaker to easy chair volume. The face plate and base board are masonite (pressboard - hardboard) that I laminated with heavy duty aluminum foil.
*** the coupling capacitors should be 10Ufd. I miss tagged C2.You could use .5Ufd or larger. The larger capacitor will give better low frequency response.

This is the schematic. I just numbered the tie points and connected the dots with the components. The circuit works well with an earbud. Adding the transformer and speaker works too.
These are good transformers BUT you must handle them with care. If you let a pin turn it will break the wire. It would be best to solder the transformer to a board and solder the wires to the board. Making and eye on the end of your lead wire and not putting it in a strain is second best.

The pin shown hear would be crimped in the middle and inserted thru the board allowing a connection on either side.
One more option if you have any.
The DBM ready for testing.
This is basically my radio except I used the Lamda Diode Oscillator. I like the LDO because it sings with any coil I put on it. I think the circuit above is a Les Haywood original from 1968. Last night I listened to a couple of hams talking in NC. With this set. It would be about 600 miles.

2 comments:

  1. How is this for tag board building - [img]http://jg3adq.a.la9.jp/50s1-vxo.JPG[/img]
    that is the VXO from a transceiver.

    Also, I like the amp photo with the 9 volt battery and foil. Which schematic goes with that build? Can't make out the values, so having a hard time matching it up.

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  2. I like that one!

    I sourced the board and pins. 79 cents an inch for the board and 29 cents each for the pins. That's a bit pricey for me. If I was building one to keep forever it would be ok, maybe?

    A friend sent me the pins in the pictures to try. Copper nails work well too but again pricey if you can find them. The wire is in the parts bin, so basically free. That works best for me.

    Thanks for pointing out the lack of a schematic.

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