Resolution...

I decided to go through and check every flippin resistor involved in the circuit and they all checked good and had been replaced a few years back.

I checked one last resistor, the one leading from the bias output. It had not been replaced but was marked in my notes as being within tolerence. I dident suspect it because the voltage checks were okay and it was simply bias to the secondary of the 2nd stage which couples to the base of the 3rd amp.

So I lifed the resistor supposed to be 1K and it measured at around 1,400. I replaced it with a new resistor, soldered everything back down and fired up the rig.

The second stage now has an actual peak in it not nearly as sharp as the first and third stage but at least now the slug doesent run out till it hits the can!

Sometimes you overlook the obvious.

Thanks for your help everyone, at least winding a new coil was a learning experience!

Actually it is a poly cap, my bad.  Your right a mylar probably would not even fit.

Well I got it rewound, fairly close to orginal, put it back in the circuit and.... well no change. Same broad tuning with no real 'peak'. After looking closer at the schematic the coil is picked off at the center tap and the far end is not connected to anything so I do not think the lack of continuity to the far end had any real impact to begin with! 

Frustration! 

tnx for the lesson, good to hear the voice of experience.

I am rewinding the coil, it is going slowly but it is going well. The patient may live.

Might even post some pics when its done.

TGF hotglue 

Well I unwrapped the sucker and here is what I got


Primary

x---10---x---24---x
==================
                           x---4---x

Secondary

It was kind of strange in that the secondary was wound on the 'end' of the primary winding and not over one another. Forgive me but I found that strange.

Let me see if I can get 38 turns of 30 ga on this former. 

The former tube is 7mm or ever so slightly larger than 1/4".

The open winding is most probably due to abuse. I had this coil open some time ago when I replaced the 330pf mylar cap that was in there. Its probably been like this for some time. The stage just never tuned right and I went all through the components of that stage. Even put in a low noise amp npn in there.

Is there any way to guestimate the number of turns required given the previous wire size and turns as compared to 30ga?

No problem counting the turns actually I havent stripped it yet.

But doesent the diamater of the wire affect things?

Wow its going around. I just lost my job of some 19 years.

Yes the IF is indeed 3.395 Mhz.

Yes it should be fairly easy to re-wind altough one winding is center tapped. However I do not have any wire that fine. I do have some magnet wire around 30awg I think (Radio Shack Red). Is there a source for the ultra fine wire?

Where can I find info on how to figure out how many turns? The tube and slug are in good shape. The original windings only take up about half the tube so I might be able to wind with the heavier wire.

The can is a little thing basically 3/4" cube anything much taller wont let the board slide in and out.

In the meantime I have some old TVs around for junk parts and see what I can dig out of those.

Its not litzwire it is single conductor, very fine. Insulated and about as think as a human hair.

Any idea on where to get such wire?

Swap it for a 1 watt 

Not quite the same thing. Resistors are easy to come by, IF cans not so much.

If anyone has a source please let me know.

BTW I found the disconnected winding, stripped a little insulation off it and checked it for continuity, its somewhere up inside the coil... geesh.

Ugh, I popped the coil out of the circuit and found a lack of continuity in one of the windings 

Now what?

This is a heathkit SB 303. It has a 3 stage IF amp each stage has a can/coil for tuning.

The first stage uses a dual gate mosfet amp/mixer. The second and third stage use a NPN amplifier.

The first and final stages show a nice sharp peak, the second stage however doesent rise till the slug is run all the way down to the stops and rises very slowly and broad and cannot be run past the 'peak'.

I wouldent really worry about it but it does seem a little numb.

Any thoughts or is this kind of normal?

Well evidently you cant modify posts here so sorry for the bump.

It turns out that the shack and the computer share the same branch circuit so maybe some common mode stuff going on there?

So yea I am not so worried now.

Thanks! 

I have a Grunding 'yacht boy' YB400PE  that at times is absolutly swamped by an AM station about 2 miles away. Even if I flip the DX/LOCAL switch (an attenuator). Its getting into the IF section somehow. It got so bad I built a notch filter for it. Only reciever I have with the issue so maybe its a Grundig architecture thing.

I am not really all that concerned about the RFI in my equipment. As has been said she just cant watch netflix while I am operationg or has to get headphones 

The dipole does run right over the house but is up at least 40 feet from the roof line. I just hope I am not getting into the neighbors stuff.

One thing I have not checked is to see if the room with the computer is on the same branch circuit as the shack. Wouldent supprise me.