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 Unikit Oscillator
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 Return to top of page · Post #: 1 · Written at 1:19:38 PM on 13 November 2018.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 4336

This is battery with a single 3S4. Radio equipment Sydney. These were a kit. This one has been put together in a disgraceful manner. To the point that coil wires are ripped off. I hope none are open?

Any one have its circuit & perhaps manual? There are holes in its case with no owner, so hacking is not out of the question.

Marc


 
 Return to top of page · Post #: 2 · Written at 5:10:49 PM on 13 November 2018.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 6003

 
 Return to top of page · Post #: 3 · Written at 8:04:58 PM on 13 November 2018.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 4336

Thanks: That's it & it also looks like getting the circuit from there will be another project.

Marc


 
 Return to top of page · Post #: 4 · Written at 8:12:32 PM on 13 November 2018.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 6003

I have no problem whatsoever downloading from Radiomuseum, nor with the files from there.

As I've mentioned before, if something on your PC is blocking it (i.e false positive), then you ought to whitelist the site.


 
 Return to top of page · Post #: 5 · Written at 6:24:45 AM on 14 November 2018.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 4336

Sometimes Firefox can be quite cranky & in the past it has had a pet hate for the Forum, for one. I would also note that there is a download site linked to that site & Malwarebytes blocked it.

However, I did get the circuit which proved two things that considered wrong, even with 1947 code. Grid leak was over a Meg high & the 5K in the divider was also a dud. 0.01μF jacket (mud) had gone funny but it is going to be tossed anyway.

That was for three reasons: It likely leaked; It was damaged; It was used as a terminal that was unstable & contributed to the fact I have four floating coil tails.

If those coils are good it will fix.


 
 Return to top of page · Post #: 6 · Written at 8:31:31 PM on 16 November 2018.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 4336

Just an observation with the OK1. After removing the valve it became obvious that due to assembly (which I have been obliged to tidy up), that the replacement of the 3S4 into its socket, is yet another way of breaking coil wires. These the way they were, are easily fouled in a valve pin.

So in essence one can have the valve break coil wire, corrosion break the coil wire, then there was flexing. I have chosen to spray the coil wires at the nodes with circuit board lacquer. Coating has always been recommended on copper to dissimilar metal, to stop corrosion.


 
 Return to top of page · Post #: 7 · Written at 9:05:43 AM on 17 November 2018.
Gandhn's Gravatar
 Location: Windella, NSW
 Member since 5 November 2010
 Member #: 770
 Postcount: 343

I remember buying (and building) one of these in my youth. I recall it achieved modulation by squegging, that is by generating the RF in bursts at an audio frequency. It was a very cheap piece of gear, perhaps its only good point.

Harold


 
 Return to top of page · Post #: 8 · Written at 11:54:02 AM on 17 November 2018.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 4336

I have the circuit from radio museum, it is a feedback circuit by transformer. However, I will find out if it has "squegging" if it fires up? I did to deal with a home/ kit radio several years ago that "squegged" : Totally undesirable in it. OK1 landed here as a repair if possible: Another collector that does not favour "Shelf Queens".

Cheap & Poorly band spread describes an SG-11, I moved recently (& now have won another minus its mains transformer) and my TE-20D, which is a clone of SG-11 is the same. TE-20D wave pattern is not exactly symmetrical, and the lack of any way to really adjust to the dial is not good. With time it is clear that the coils in all, have drifted in characteristic, & changing valves & voltage fluctuation, is guaranteed to exacerbate it all.

Having said that, it is stable enough to set old radios so long as you understand its limitations and what niche it was designed for. It has provision for crystals, but if you really needed one for each IF frequency. My answer was a frequency counter the first an EA Kit that had issues with its upper frequency range. I still have it but now use a Fluke.

There are of course traps with all test equipment: You need to understand it. It too has limitations. With both counters, feeding them modulated RF is an absolute "No No".


Marc


 
 Return to top of page · Post #: 9 · Written at 8:36:37 PM on 1 December 2018.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 4336

Update: I have sorted out all of the broken wires & miss wires (Gang stator grounded) doubt it ever ran. It has failed to fire up but the valve may actually be faulty? Alternate wrong phase all coils had broken wires.

Interesting that the circuit diagram is wrong. The layout diagram indicates caps 0.01mfd and two 500pF caps. One does not appear in the circuit diagram. As the valve has a grid leak why is there not the other 500pF between the control grid & coils that render the grid leak useless, the way the circuit is drawn.

Marc


 
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