Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

donate to eham
   Home   Help Search  
Pages: [1] 2 Next   Go Down
  Print  
Author Topic: Siltronix 1011C  (Read 6348 times)
KOP
Member

Posts: 346




Ignore
« on: March 31, 2016, 09:51:35 PM »

First things first ,
I know they drift .
I know there is a debate about their legality , a bootless argument, and I don't care .
I know the 8950 is rare and in some cases worth more than the chassis .
I have all the documentation available on the web unless someone has a detailed parts identification photo or photos .
What I'm looking for is actual experience resurrecting one of these .
Specifics so far are ...
Where is the -12V supply zener located and what does it look like ? I suspect its something weird , antique and as old as I am .
Where is a good place to check for -12V in the vfo ?
Where is a good place to check for output frequency from the vfo (this I may have if I can just unscrew the inscrutable , I can decipher a schematic ) .
What is up with the 26.93xx mhz output with a serious 60hz in it ? Nearly 150W with an ugly tone . The output does not change with vfo and is somewhat frequency sensitive to final tank settings .

Here is the reason I want to repair / restore this boat anchor . I want to . No other reason than I have a stash of tubes , a few spare parts , a soldering iron and what printed materials I can find on the web . Although comparing apples with oranges I did this with a Viking II , A D-201 , a Tempo One and a Uniden 2020 so with just a bit of shared experience I can probably get this done .

I'm asking because the available information is a bit pitiable if not just incomplete .
I'm not new at this by a long shot . I just need someone that has been here to please speak up .

~kop   
 
Logged

I considered a microwave oven magnetron and a 4' dish as a drone-killer. The ERP would be on the order of a hundred thousand watts or so. ~anon

November 28, 2018, 09:16:04 AM
AA4HA
Member

Posts: 2630




Ignore
« Reply #1 on: April 01, 2016, 10:43:17 AM »

On the power transformer find the white wire, it will attach to a rectifier diode, D1711 that is a 1N4005.

The other side of the rectifier diode attaches to two resistors, you want to find R1709 that is a 800 ohm, 10 watt (big) resistor. Follow through that.

You will now find another big resistor, this is a 500 ohm 10 watt (big) resistor. Follow through that.

On the other side of that big resistor there will be a small glass diode, this is D1712, this is a 1N4712 zener diode that regulates the -12 volt supply.

The 1N4712 diode is still made.

Those resistors in series drop the DC voltage from the rectifier diode and capacitor down to a range where the zener will not up and die.

The only things the grey and white wires on the transformer do is to supply the -100 and -12 volt output.

While you are at it, you may want to check the power supply capacitors. This is an old(er) rig and they are probably getting a bit iffy. A shorted cap will burn out the two bridge rectifiers that supply 250 and 800 VDC or the diode D1711 that supplies the negative voltages.

If you ever have to replace the black rectifier 1N4005 diodes you can put 1N4007's in there. The 1N4005 is a bit light duty as far as voltages are concerned for the 800 volt supply. The price difference between a 1N4005 and 1N4007 is just a few cents more. The 1N4007 is rated for up to 1000 PIV (peak inverse voltage).

--------------------
It will make some people on here crazy, but here is a schematic... on a CB radio site;

http://cbtricks.com/radios/siltronix/model_1011c/graphics/siltronix_1011c_om_sch.jpg
« Last Edit: April 01, 2016, 10:45:49 AM by AA4HA » Logged

Ms. Tisha Hayes, AA4HA
Lookout Mountain, Alabama
WB6BYU
Member

Posts: 18533




Ignore
« Reply #2 on: April 01, 2016, 12:06:40 PM »

Quote from: KOP

What is up with the 26.93xx mhz output with a serious 60hz in it ? Nearly 150W with an ugly tone . The output does not change with vfo and is somewhat frequency sensitive to final tank settings .
 


Sounds like a self-oscillation somewhere.  It could be any of the amplifier tubes - final, driver, mixer, or IF.
Quickest way to track it down is probably to pull the tubes one by one (starting with the final) and sniff
around with a receiver to see if you still hear it.  (Note that the 6GK6 driver is in series/parallel with other
6V tubes - you may also need to pull V9, V11 or V13 to help keep the voltage reasonable.)

If the IF stage is oscillating around 5.386 MHz the 5th harmonic might be slipping through the mixer.

Neutralizing the final might be all it needs, though if the tuning and loading controls don't affect the
frequency I'd guess a different stage is oscillating.
Logged
KOP
Member

Posts: 346




Ignore
« Reply #3 on: April 01, 2016, 02:09:27 PM »

First off Tisha , Dale , Thank You .
                  I have verified the -12V supply and VFO output . (thanx Tisha!).
I haven't had to translate pictographs into point to point wiring in some time so the eyes on experience helped .

The HV rect/filter board is going to get replaced entire. with the covers off and the radio upside down turning the power on resulted in a tiny spark . one of the filter caps had unsoldered itself and the resultant arcing , carbon , corrosion and crap would not take solder . The traces on the board will not take heat and the addition of regular 60/40 rosin core results in a useless brew that I don't care to deal with . I had to look close to see it and it didn't happen all the time . It seems that if the cap was charged there was less of a spark (well yeah) and if simply turned off and on within seconds there was none . Let it sit 30 seconds to a minute and the spark was there . Bleeder resistance must be working . The HV supply board is easily (kinda) removed with just two nuts and tipped out of the way for inspection and repair . Imagine the hum if the board isn't screwed back in place . I tried just for testing but ...

I have found the 22 and 24mhz out from the VFO , the 5mhz from the reference oscillator but as of yet no 27-28mhz at the mixer . So the mixer itself or the VFO amp .

Dale , I'm right there with you .  The tuning and loading controls do affect the
frequency , however not by much .

I've done what I can so far now its on to verifying the tubes themselves (again?!) and see if I can kill the self oscillation.

~kop
Logged

I considered a microwave oven magnetron and a 4' dish as a drone-killer. The ERP would be on the order of a hundred thousand watts or so. ~anon

November 28, 2018, 09:16:04 AM
W9GB
Member

Posts: 3380




Ignore
« Reply #4 on: April 05, 2016, 07:00:02 PM »

Quote
I know the 8950 is rare and in some cases worth more than the chassis .
Sadly, I saw an individual buy one, take out the immaculate tubes,
and threw chassis in dumpster as he left flea-market/hamfest.
http://cbtricks.com/radios/siltronix/model_1011c/index.htm
You can convert to the 6LB6 tube.

The 7360 balanced modulator tube (some models) can also be difficult to locate.

Skipp at RadioWrench has web page for Siltronix 1011 owners.
http://www.radiowrench.com/siltronix/

Kansas City Northlanders on 1011C
http://www.northland-drifters.net/1011CProject.htm
===
The 1011D, Commanche model is different (6JH8 balanced modulator)
However, the photos are useful.
http://kc9ich.com/Siltronix/Siltronix1011D.pdf
« Last Edit: April 05, 2016, 07:10:20 PM by W9GB » Logged
N8YX
Member

Posts: 1397




Ignore
« Reply #5 on: April 06, 2016, 10:12:04 AM »

Depending on intent, I would just clean the Siltronix unit up then place it carefully on the shelf for display. Next, locate an FT-101E/EE or F and perform the requisite surgery to make it like you want it.

Much better radio.

My FR/FL series - both current and previously owned - got 30, 17 and 12M added to the RXes and 17/12M added to the TXes. Modding the FT is a bit easier.
Logged
KOP
Member

Posts: 346




Ignore
« Reply #6 on: April 06, 2016, 11:02:42 AM »

Depending on intent, I would just clean the Siltronix unit up then place it carefully on the shelf for display.

Fred I appreciate the sentiment but I am going to do this.

Next, locate an FT-101E/EE or F and perform the requisite surgery to make it like you want it.

Been there , do that :-)


Much better radio.

No argument here , at least from the standpoint of coverage and capability .

My FR/FL series - both current and previously owned - got 30, 17 and 12M added to the RXes and 17/12M added to the TXes. Modding the FT is a bit easier.

https://www.inrad.net/files/Pubs/FT-101%20-%20Installing%20the%20WARC%20Bands%20Mod.pdf

As I said , been there , did that , MC12060 and MC12061 crystal oscillator integrated circuits by utilizing diodes as RF switches. The switching is
controlled by applying a forward bias to the diode associated with the desired crystal and applying a reverse bias
to the remaining diodes related to the unselected crystals

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwjP4p-ty_rLAhVQ7WMKHWe8DUkQFggdMAA&url=http%3A%2F%2Fwww.lansdale.com%2FArticles%2Fan756.pdf&usg=AFQjCNEN0cEolGOIcPh4l01QHEGH_fUj_g&sig2=kWAXuNGGgJXcvG8Zyjai1Q

The band coverage isn't nearly as important as , well , Siltronix ...

Not like I don't appreciate the advice but this is about making a 1011C live again .

~kop
Logged

I considered a microwave oven magnetron and a 4' dish as a drone-killer. The ERP would be on the order of a hundred thousand watts or so. ~anon

November 28, 2018, 09:16:04 AM
KOP
Member

Posts: 346




Ignore
« Reply #7 on: April 06, 2016, 11:07:16 AM »

...Moving right along ...

     Tubes and VFO parts due today so I'll update thoroughly tonight . Thank You all again for the help and comment !

~kop
Logged

I considered a microwave oven magnetron and a 4' dish as a drone-killer. The ERP would be on the order of a hundred thousand watts or so. ~anon

November 28, 2018, 09:16:04 AM
KOP
Member

Posts: 346




Ignore
« Reply #8 on: October 12, 2018, 10:40:49 AM »

Is it necroposting or just self abuse  when you post to a thread you started two years ago?

I found a crack in the VFO capacitor support that would not under any circumstances allow for correct VFO output.
A note for future Radio wrenches that attack linearity of this VFO. You'll note that the moving and stationary plates are not quite parallel .
Until you actually find the ends of the 27 and 28 dial don't even try to straighten it out. I think you'll find that it is by design.
Tisha I didn't convert to a solid state regulator as these original parts seem very stable.
I managed to get all the voltages where they are supposed to be but I'm leaving the PA for last. I have a limited number of 8950's so I'm making sure.

One last note for those that seldom work on tube gear. Sacrificing a scope probe  to these rigs is a real possibility. You see, a high impedance location in the oscillator chain that won't load the oscillator usually equates with a High voltage. Couple this with a DC coupled probe and the results can be tears if not shocking.

I'm off to plotting a filter on a piece of paper to find out where the carrier insertion points "should" be. In a rig this old the as written specs are meaningless. Don't ask why I have to do this the hard way :-/  (parts are on the way)

I'm hoping to check into the weekend 10m nets but I know better than to get in a hurry. Thank You to all as it is difficult to get answers or information without multiple sermons from the "Church of St Hiram" . Your assistance was and is very much appreciated
Logged

I considered a microwave oven magnetron and a 4' dish as a drone-killer. The ERP would be on the order of a hundred thousand watts or so. ~anon

November 28, 2018, 09:16:04 AM
KM1H
Member

Posts: 5555




Ignore
« Reply #9 on: October 12, 2018, 11:38:35 AM »

You can install a VFO Stabilizer board to get away from the SWAN drift. Ive talked to many on 10M over the recent years.
Logged
KOP
Member

Posts: 346




Ignore
« Reply #10 on: October 12, 2018, 11:45:25 AM »

As designed they wern't really that bad. Batch part variations took their toll as did 40 years :-/
Logged

I considered a microwave oven magnetron and a 4' dish as a drone-killer. The ERP would be on the order of a hundred thousand watts or so. ~anon

November 28, 2018, 09:16:04 AM
KOP
Member

Posts: 346




Ignore
« Reply #11 on: October 14, 2018, 10:35:24 PM »

I found a crack in the VFO capacitor support that would not under any circumstances allow for correct VFO output.
A note for future Radio wrenches that attack linearity of this VFO. You'll note that the moving and stationary plates are not quite parallel .
Until you actually find the ends of the 27 and 28 dial don't even try to straighten it out. I think you'll find that it is by design.
Tisha I didn't convert to a solid state regulator as these original parts seem very stable.
I managed to get all the voltages where they are supposed to be but I'm leaving the PA for last. I have a limited number of 8950's so I'm making sure.

One last note for those that seldom work on tube gear. Sacrificing a scope probe to these rigs is a real possibility. You see, a high impedance location in the oscillator chain that won't load the oscillator usually equates with a High voltage. Couple this with a DC coupled probe and the results can be tears if not shocking.

I'm off to plotting a filter on a piece of paper to find out where the carrier insertion points "should" be. In a rig this old the as written specs are meaningless. Don't ask why I have to do this the hard way :-/ (parts are on the way)

I'm hoping to check into the weekend 10m nets but I know better than to get in a hurry. Thank You to all as it is difficult to get answers or information without multiple sermons from the "Church of St Hiram" . Your assistance was and is very much appreciated
Logged

I considered a microwave oven magnetron and a 4' dish as a drone-killer. The ERP would be on the order of a hundred thousand watts or so. ~anon

November 28, 2018, 09:16:04 AM
KOP
Member

Posts: 346




Ignore
« Reply #12 on: October 14, 2018, 10:35:53 PM »

1) if left open and powered on the bench with a half eaten snack in near proximity it makes a serious rat trap.
Tripped the bench iso and power strip but not after thoroughly cooking the rodent
2) DC coupled scope probes and looking for a high impedance point in a circuit that won't load the oscillator usually points to a high voltage.
3) There is a reason for DDS instead of PLL instead of PTO instead LMO instead of VFO instead of ...
Getting this low budget VFO linear over any semblance of of it's width is voodoo that I rarely do. Now I remember why .
4)Mentioning a piece of equipment that is even remotely considered "CB" quickly separates the pontificating minions of the "Church of St Hiram" from some of the best people I have met here and on "teh 'Zed" . It was my welcome introduction to Tisha and Dale among others.
5) just because a carbon resistor measures within tolerance on initial diagnosis does not mean that it will survive even initial turn on.
6) Same holds true for HV capacitors. See above. Nothing like a HV party popper to get your heart started (or stopped) and spread confetti all over the bench.
7) input impedance of a 12AX7 grid is NOT 500 ohms. In my defense I have two identical mic bodies, one with a ceramic element and another with a 500 ohm voice coil. At least it was a 500 ohm voice coil. I didn't properly check the mic jack.
Cool Show me a radio that is idiot proof and I'll prove you wrong. In the words of Robert Anson Heinlein, "Never underestimate the power of human stupidity. This includes your own."
9) There are very good reasons for a non conductive bench top. Setting the radio down with the bottom exposed , on tools left on the bench , negates this careful preparation .
Logged

I considered a microwave oven magnetron and a 4' dish as a drone-killer. The ERP would be on the order of a hundred thousand watts or so. ~anon

November 28, 2018, 09:16:04 AM
KOP
Member

Posts: 346




Ignore
« Reply #13 on: October 14, 2018, 10:36:55 PM »

Then leaving it on over night to find this in the morning


Logged

I considered a microwave oven magnetron and a 4' dish as a drone-killer. The ERP would be on the order of a hundred thousand watts or so. ~anon

November 28, 2018, 09:16:04 AM
VK4MF
Member

Posts: 16




Ignore
« Reply #14 on: October 15, 2018, 01:00:50 AM »

Hi,i see your thread is 2 years old,but just wanted to know if you need any parts for your siltronix 1011c,i have an old scrapped radio chassis with tubes and parts,most pulled apart,i live in Australia and mot sure on freight cost but the cost of shipping is all i want for these items,i would guess at $50.00 Australian dollars + - if interest ..
regards Keith vk4mf
kif@iprimus.com.au
Logged
Pages: [1] 2 Next   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!