Re-greening the Heathkit IG-18

[DDB]

Dick has posted a major update to his mod #3 of the Heath IG-18 using a HP339A style design. IG-18 #3

 

[richiem]

I've completed two variants of putting the HP 339A oscillator circuit into an IG-18 -- one is the 339A circuit using the 100:1 tuning cap ratio:
IG-18 #3, the IG-339A and B

The second is the 339A circuit using the Heath stock tuning caps:
IG-18 #4, the IG-339B

The pages include high-res distortion spectra, showing 1kHz results in the 1ppm area. Neither of these are quite as good as Bob Cordell's SV circuit in the IG-18, but they're still very good.

 

[klewis]

Dick,

It all looks very good! A question for you about your boards, the ferills that you fit the JFET and some resistors into, where did you get them? Part number? I presume they are for easy swapping of parts.

Ken

 

[davada]

Dick,

It all looks very good! A question for you about your boards, the ferills that you fit the JFET and some resistors into, where did you get them? Part number? I presume they are for easy swapping of parts.

Ken

Hi Klewis,

I'm not sure where Dick got his but I have seen at Digikey.

David.

 

[richiem]

Hi Ken -- those are Augat socket terminals for wire wrap. Got them a million years ago and have no idea now what the part number is. All I can remember is that they came from Digi-Key. They have collet-type sockets very similar to the pins in good DIP sockets.

 

[davada]

Hi Ken -- those are Augat socket terminals for wire wrap. Got them a million years ago and have no idea now what the part number is. All I can remember is that they came from Digi-Key. They have collet-type sockets very similar to the pins in good DIP sockets.

Hi Dick,

That's a very good point about the dip sockets. I have disassembled a few collet type 8PDIP sockets and used the pins for SOIC breakout boards. A bit of solid wire inserted into the socket pin and then into the breakout hole holds the pin while being soldered.

I find this produces a much better end result than using male header strip.

Cheers,

David.

 

[Damon Hill]

IG-339? I like it! Somehow I have to scrape up money for parts to get my SV oscillator board up and running.

 

[klewis]

Hi Ken -- those are Augat socket terminals for wire wrap. Got them a million years ago and have no idea now what the part number is. All I can remember is that they came from Digi-Key. They have collet-type sockets very similar to the pins in good DIP sockets.

Found them at mouser, had to resort to the paper catalog. R32/C Vector | Mouser

note that the price is for 100 pieces.

 

[davada]

These are available at digi. $0.65 for one.

http://www.mill-max.com/images/products/pdf/166N.pdf

David.

 

[mrsavage]

new PCB's board designs

Other PCB designs exist, but what about a new one that includes the latest
op-amps and voltage regulators. I would be interested in a group buy for these
new designs.