Hello radio people,
I'm a retired radio/television serviceman, period 1966 to 2000.
Was given an old Monarch BKJ which was on its way to the tip.
Anyway have made it one of my projects.
Have got it going(o/c filter choke), but over the years the unit has had a lot of unsavoury appearing work done to it and the
whole performance is fairly weak and poor.
It has a number of modern components dagged here and there.
Also the plate voltage on the audio preamp is only around 15 volts(6CA8G).
I think the preamp is meant to be a 6B6G to start with.
Has anyone got a circuit so I can put it back to original to start with.
Thanks, JJ

If you unhide your email address (use Control Panel) I'll send you the schematic and notes.

Thank you, I think I have successfully unhide the address.

I'll get Brad to upload them so they are available for all in the future.

Eclipse and Monarch BKL Circuit Diagram
Eclipse and Monarch BKL Parts List

Okay, sent.

Received all OK, its great to get some solder fumes back in the workshop.
So far just putting the correct valve in the detector/preamp position has increased the performance 50%.
Removing the shorted cathode of the 6V6 to deck has improve the audio quality and looking at the circuit AGC action as well.
I assume the man made short from cathode to deck was someone's attempt to make it louder.
And probably explains why the filter tx was o/c initially due to excessive current!.
A few other things I have to checkout yet, then cabinet cleaning.(mainly paint all over the radio).
Then the normal preventive repair procedures.(paper caps and electos if needed).
Will report back later. I wish that I took a before picture.
Speaker cloth looks a mess, not sure what to do there.
In the good old days all I had to do is fix them and sometimes I might have left the mouse poo in the radio as well .
And have a happy customer.
Thanks again,
JJ

Files uploaded to Post 4.

Well this Monarch has finally come off the assembly line.
Electrically refurbished, made safe and reliable, new speaker cloth, paint cleaned off cabinet, and found some proper 6V6G, and
5Y3G valves to replace the GT types.
Performance is very good, and as they used to say "lovely tone". .
Pictures hopefully sent to Brad.
Thanks for everyone's help.
JJ

Photos uploaded to Post 8.

Good job.

BTW: Have you replaced the 'death caps' in that LSG-11 sig gen?

Not intending to be insulting: I think that should be all of them, depending on who built it. I have one here (surplus to requirements) that had "oil filled" caps in it: They are as bad as waxed paper.

I really don't know how these got into the country? I got rid of the "death caps" and fitted a grounded cable. The problem I have is that it is a metal case, regs. have always basically said that "if it can become live" it should be grounded. And a cap that is not a proper line cap, from line to a metal case & chassis that has no mains ground, is a death trap.

Yes the sig gen while not my most accurate bit of test equipment is still used.
Has been refurbished three times in the last 40 odd years, but I must admit that I was not aware/or missed the importance of the
caps across the mains switch and to deck until I joined this forum.
So, thanks to all. That has been recently rectified!
JJ

I would concur that these and their clones are not spectacular but at least they are reasonably stable, Even with a NOS set of valves the high frequency end can be unpredictable and I do wonder why they never used the universal widget valve 6BL8. That is a Triode Pentode frequency converter and were as common as dishwater.

As it is good for around 200Meg it would have been ideal. Specs (Philips) quote 100V as an oscillator and that is a little bit less than the "B" Voltage of those things: Which is the undoing, as far as I am concerned of the output wave form.

There is actually no grid info on one tube for 100V area. From what I see on the oscilloscopes and the valve sheets 100V puts its operating point on the "knee curve". Doing that causes the negative & positive going parts of the wave to be dis proportionally amplified.

Be aware, that this is not the only piece of metal cased equipment, that has slipped in under the radar with caps mains to a non grounded metal case. I have others.

I have an old Dick Smith (EA) Kit Frequency counter with a faulty segment & a Fluke one that I calibrate mine with ( do not do it with modulation on) and I note some very cheap and very small modules that you could use on it. And that way as long as you have the meter calibrated, it's to hell with what is on the dial.

I calibrated the Dick Smith counter using WWV & WWVH & often check the Fluke & comms receiver, against them.

Marc