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Siltronix 1011
- Thread starter kopcicle
- Start date
I can only verify one, C907 40MFD - part of V9.
Other? Possible Audio Out cap to couple to AF Amp?
OR...
By nature - related to Driver Tube?
Other? Possible Audio Out cap to couple to AF Amp?
OR...
By nature - related to Driver Tube?
I can find C907 on "C" Parts list, just looks to be an upgrade for the "D" version.
So it may be useful to reduce unknown issues we have yet to see develop. They just are on a high voltage line across it, to ground - which tells me filtering is their main purpose. Schematically they are non polarized - so they are filter related - but not a polarization type of install where more precautions for polarity as well as their ratings. In the photo they are oriented in a fashion that the case side of the caps skin went to the Low side so install orientation is important.
They impact Plate feeds so presume possible "damping" for either Audio parasitics - or an errant Mouse or Rat that strays too close to the "Quantum Coupler" that 8950 can become.
So the addition of the parts may not be a requirement for the "C" version of this chassis - but for it to exist in photos in both the B & W "C" manual I found on CB Tricks - and your Color Photo - both show similar alignment position as if a template was followed during assembly. So if this wasn't put on yours when you got it - it would not hurt to put them in there and not cause any issues because - if someone that may have done an unwarranted mod (as I learned earlier) and had simply followed the diagram - may wind up on the floor...but due to their appearance in one set but not in all cases - had they remained "charged" during the repair - is what I'm referring to. It appears not necessarily as a "takata - must remove SRS" but more of a performance feature of cleaning up small details yet to be discovered.
I hope this is not turning into a ex-potentiating cost repair job...
So it may be useful to reduce unknown issues we have yet to see develop. They just are on a high voltage line across it, to ground - which tells me filtering is their main purpose. Schematically they are non polarized - so they are filter related - but not a polarization type of install where more precautions for polarity as well as their ratings. In the photo they are oriented in a fashion that the case side of the caps skin went to the Low side so install orientation is important.
They impact Plate feeds so presume possible "damping" for either Audio parasitics - or an errant Mouse or Rat that strays too close to the "Quantum Coupler" that 8950 can become.
So the addition of the parts may not be a requirement for the "C" version of this chassis - but for it to exist in photos in both the B & W "C" manual I found on CB Tricks - and your Color Photo - both show similar alignment position as if a template was followed during assembly. So if this wasn't put on yours when you got it - it would not hurt to put them in there and not cause any issues because - if someone that may have done an unwarranted mod (as I learned earlier) and had simply followed the diagram - may wind up on the floor...but due to their appearance in one set but not in all cases - had they remained "charged" during the repair - is what I'm referring to. It appears not necessarily as a "takata - must remove SRS" but more of a performance feature of cleaning up small details yet to be discovered.
I hope this is not turning into a ex-potentiating cost repair job...
Cost really isn't an object.I've had this around for far too long and aside from the education I just want it to work. I got over my head and then life happened as a few of you know. Getting the receive on line as well as tinkering with the VFO endlessly was mind numbing.
https://www.worldwidedx.com/threads/why-we-wont-just-upgrade-your-siltronix-vfo.220328/
I really should have taken this to heart. Im a stubborn SOB or a stupid one so I had to find out for myself. I have completely rebuilt an R390(A) so this "should" have been a snap , right? Wrong, different animal and pedigree altogether. This took not only misplaced confidence in my abilities and experience but repeated conversations with Nomad. (Thank You again, still?) . Skipp May contributed several emails as well. Humbling indeed when the people that have gone before take the time to help.
I'd do it again in a heartbeat. In fact I've been in conversation with Dmans about a dusty critter on evilbay not sixty miles away from him .
https://www.ebay.com/itm/SILTRONIX-RADIO-1011C-PARTS-OR-REPAIR-FREE-SHIP/123006082753
Dave, my birthday is coming up ...
I won't pass on another one for the right price even full aware of what a complete rebuild costs in time and brain sweat. One day I'll have my own.
https://www.worldwidedx.com/threads/why-we-wont-just-upgrade-your-siltronix-vfo.220328/
I really should have taken this to heart. Im a stubborn SOB or a stupid one so I had to find out for myself. I have completely rebuilt an R390(A) so this "should" have been a snap , right? Wrong, different animal and pedigree altogether. This took not only misplaced confidence in my abilities and experience but repeated conversations with Nomad. (Thank You again, still?) . Skipp May contributed several emails as well. Humbling indeed when the people that have gone before take the time to help.
I'd do it again in a heartbeat. In fact I've been in conversation with Dmans about a dusty critter on evilbay not sixty miles away from him .
https://www.ebay.com/itm/SILTRONIX-RADIO-1011C-PARTS-OR-REPAIR-FREE-SHIP/123006082753
Dave, my birthday is coming up ...
I won't pass on another one for the right price even full aware of what a complete rebuild costs in time and brain sweat. One day I'll have my own.
Back to the original post. I have a junked out chassis I'll take to the hardware store tonight to fill with the appropriate fasteners. Hopefully that cures the chassis flex/frequency drift issues. I'm going to deliver the parts chassis with the radio so the owner has a chance and some resources to keep this one alive.
I admire your steadfast heart being put into something you have to turn around and let go once it's all back to the glorious "Miss America" it deserves to be...I only hope the owner understands the effort of one that still enjoys radio, is the same guy that enjoys coffee...
I can only hope the ability you have in making this work - can somehow encourage others to keep going.
Meanwhile back at the Siltronix...
Square at lower left " 80MFD @ 400V C-1712 "A" Red to 800 ohm 10W and W/Red to ...
Semi-circle lower right: 80MFD @ 400V C-1712 "B" Small Red to the other side of 800 ohm 10W , large red to Rect/Filter board, .01 MFD orange drop to pin 6 of V11 6GW8, 3.3K ohm to pin 6 V7 12BA6
Triangle at upper left : 5 @ 400V W/Red to T/R relay & W/Red ?
---O--- at upper right" 5 @ 400V Pin 3 V11 6GW8 Blue
I think that covers it. All I need to do now is a "clean" way to get this done. There isn't a whole lot of room here for another terminal strip but severaal ground tabs available within easy reach. The two 500V 100 MFD will replace the two 80MFD @ 400V with a two section cap and the 5MFD @ 400V will be replaced by discrete axial electrolytic capacitors.
@nomadradio , suggestions ?
For those of you that have a long memory or have been following along at home...
The hidden gem in this one was the .01 ceramic disc between pins 6 & 7 of V10 , 6AV6, the AGC amp. You wouldn't believe all that goes wrong if this cap isn't present or connected.
The even more hidden and frustrating fauld was a crack in the ground side of the main VFO variable cap. Once mechanically stabilized and soldered the VFO actually worked. Then there was an entire afternoon of adjusting the plate of the capacitor in sections to get a somewhat accurate spread that agreed with the dial. It was a choice between a complete mechanical rebuild of the VFO ( I did have the parts) or a repair of what was there. In the end a toss up and a challenge to fix what was there. In retrospect , start over was probably a better option. If you ever attempt to get this VFO to agree with the dial across .45MHz you'll understand why. In the end I go it to agree "near" channel one and channel 40 is about 17Kc low . Close enough for the girls I go out with
Attachments
But wait , that's not all! The "carrier" now acts like carrier balance :-(
I can tune out the carrier or put it in for AM.
With the cap replacement I thought the deadly dyna-mo-humm was fixed but...
Now it's fixed in AM and USB but LSB receive hums like a Brazilian whore.
I will now attempt to exorcise the demon that seems to have moved from the IC-735 to the Siltronix.
Do I need to mix my DeOxit with holy water?
I can tune out the carrier or put it in for AM.
With the cap replacement I thought the deadly dyna-mo-humm was fixed but...
Now it's fixed in AM and USB but LSB receive hums like a Brazilian whore.
I will now attempt to exorcise the demon that seems to have moved from the IC-735 to the Siltronix.
Do I need to mix my DeOxit with holy water?
And still more.
We have nothing like 60-80 watts output but the station 300ft away says it doesn't transmit too awfully bad. When asked he said "There is no transmitted hum".
I'm looking at bias and neutralization , again.
We have nothing like 60-80 watts output but the station 300ft away says it doesn't transmit too awfully bad. When asked he said "There is no transmitted hum".
I'm looking at bias and neutralization , again.
the brazilian whore used your DeOxit with holy water for a douche
The front-panel carrier-level control is really a carrier imbalance control.
The two balance pots inside the radio are still active when you crank the imbalance pot on the front.
Had a customer years ago who figured this out, and became fond of balancing out his sideband carrier manually, using the front-panel control.
This required setting the fat internal carrier-balance pot with the one on the front panel cracked up a couple of notches from minimum. This caused the carrier null on sideband to be adjustable from the front panel. Gave him some leeway to minimize the radio's carrier in sideband mode. He was using the 5-Watt scale of his wattmeter for this, once the radio warmed up. Don't remember him blowing up his wattmeter. Maybe he really did have something on the ball.
Told him there was no real benefit to being that fanatical about a small bit of carrier leakage. He still insisted on nulling it before hitting the upper channels.
There are worse obsessions, I suppose.
73
The two balance pots inside the radio are still active when you crank the imbalance pot on the front.
Had a customer years ago who figured this out, and became fond of balancing out his sideband carrier manually, using the front-panel control.
This required setting the fat internal carrier-balance pot with the one on the front panel cracked up a couple of notches from minimum. This caused the carrier null on sideband to be adjustable from the front panel. Gave him some leeway to minimize the radio's carrier in sideband mode. He was using the 5-Watt scale of his wattmeter for this, once the radio warmed up. Don't remember him blowing up his wattmeter. Maybe he really did have something on the ball.
Told him there was no real benefit to being that fanatical about a small bit of carrier leakage. He still insisted on nulling it before hitting the upper channels.
There are worse obsessions, I suppose.
73
And the 60cy hum is much more noticeable on LSB receive and transmit.
More tomorrow .
More tomorrow .