Siltronix 1011

[Dmans]

I would think that the capacitors in the VFO section of the schematic marked “ * Selected Values” May warrant careful scrutiny as it is my guess these would be the first items tinkered with 40 or so years ago by some to cause this classic to transmit on 11 meters as opposed to receive only.
Might have caused some linearity issues with the carefully planned VFO. Maybe not.

At least you have sent a message to the rodent population of your zip code. But, I could be wrong.

73’s
David

 

[kopcicle]

Well now we move on from VFO linearity to a very weak receive. I'm looking at the whole RX chain but as a first guess following the meter to pin 6 of V7 makes me suspect everything from V5 the RF amp through the filter and on to V10 the AGC amp.
I'm checking voltages right now and trying not to end up like my dearly departed rodent assistant.

 

[Redbeard U812]

View attachment 25720

Thanks Kopcicle,

Did not have one of those. Printed a hard copy just in case an EMP strike takes out all electronic equipment. Then again, if all equipment goes fubar, guess a hard copy won't be worth chit.

 

[Handy Andy]

I'm checking voltages right now and trying not to end up like my dearly departed rodent assistant.

I've got a copy "tabbed" so I can work alongside you today for a little while.

Right now, just "how much" of a carrier is the RF chain producing? Usually, when I smell a rat (Sorry) it also is sending in arcs thru the RECEIVE mode and whatever is arcing past the rodents carbon "tail" (trail?) may have arced into the RF amp - a weak receive can also be translated as an IF leaking image problem swamping out a stage or two from it being stronger than the RF arriving...that is providing the RF amp and it's "grid" issue is not oscillating or shorting out the chain...

You may or may not see a carrier that way off in neverland - but we'll save that jar of Peanut butter as food for thought for later...

 

[Handy Andy]

The "leak" I'm referring to...


Transmitter "Mixer" can send IF image back into RF RX chain - just pull/swap the tube if you can to see if RX returns
(OK don't yell - I'm trying to locate a problem of getting IF to appear - IF needs a signal yes, but check the tube!)
Found only a few tubes with filaments that are paired with others....

 

[kopcicle]

'mornin Andy. I am in my first cuppa and checking the entire chain this morning. First is the voltages at the base of each tube. New scope probe arrived yesterday so tracing signal is back on the menu. Currently I have the RCA tap from my cantenna banana patched directly into the silly. It hears the syn/gen (actually a HR2510 since I have a few around) just fine. I just have no indication from the meter. The meter does the full scale when turned on thing and settles to zero as the audio wakes up. The meter also reacts to the meter zero pot on the back as it should. I was able to track the VFO (actually verify the frequency of the syn/gen easily. In fact I needed to turn everything down to hear the zero beat. The receiver may not be completely dead but the meter is completely blind .

...more coffee

 

[Handy Andy]

That's good! Keep goin'! I'll make a pot for myself...

Good to know you have a heartbeat - still a heartbreak - but it's alive...

Just thinking this little project whether you're done with it or not, will be helping to keep you and the shack warm this winter...

 

[kopcicle]

I have a brother by a different mother that wants and deserves the effort. It will be gracing his desk as soon as I get it right. The functional first then I have the covers restored and waiting . The face is near perfect to start with. I'm in search of a four section can 80-80-5-5 @ 400wvdc

 

[Handy Andy]

Are your Solid States - Q1 and Q2 (VFO OSC and AMP - respectively) Q3 and the Diodes - ok? (As the Band played on...)

C205? Ok? Saw what you meant by the "meter swing" - that too is a delicate operation - any arcing of the 8950 tube - yeah it can fry the relay contacts easily enough. The meter won't give you anything until the 8950 is installed...so yes - verify the Driver V3 is ready before any attempts...

Are the Xtals using Q3 at the Mode Switch still good?

 

[kopcicle]

...update C1004 , .01 between pin 6 & 7 of V10 the AGC amp , disconnected @ pin 6 .

I posted the schematic and didn't pay attention to it myself :facepalm:

At least it didn't cost me another probe .

 

[BJ radionut]

Kop: I looked around Antique Radio Supply/Part Express/ and another one of my restoration suppliers...NO LUCK on your cap!!! found a Twin 80uf at 500v...but not the small sections.
GL...mabe Nebraska Surplus...but hold onto your wallet if they sell it!!!
No Fresh stock I could find on that combo! May have to break the connections apart and go it that way.
All the Best
Gary

 

[sunbulls]

I have a brother by a different mother that wants and deserves the effort. It will be gracing his desk as soon as I get it right. The functional first then I have the covers restored and waiting . The face is near perfect to start with. I'm in search of a four section can 80-80-5-5 @ 400wvdc

Good luck finding hens teeth. I usually end up stuffing an old can with new axial caps. I cut the can apart about 1 inch from the bottom with my Dremel cutting disk and remove all the innards. After the new caps are tied together, leads soldered, insulated etc., I put the top of the can back on and secure it with copper tape. Except for the ribbon tape covering the cut, it looks stock and can be easily removed for future renewal.

 

[nomadradio]

We use this part in the Tram D201 radios.

https://www.cedist.com/products/capacitor-jj-electronics-500v-100100-f-electrolytic

Of course you'll need a mounting clamp for it.

https://www.cedist.com/products/capacitor-clamp-1375-diameter

CE Distributing is not the only source of this type capacitor. There are other brands, like LCR or F&T marketed for repairing guitar amplifiers. Antique Electronic supply carries one or more of those.

They have proven the most cost-effective sub for the old twist-lock parts. You'll have to drill out the rivets that held in the mounting plate or "saddle" that held the old part. The screw holes in the new clamp will line up with the holes in the chassis just fine.

73

 

[kopcicle]

...then just dangle the two 5uf , "somewhere"

 

[kopcicle]

I don't have these in mine ????