Author Topic: Com Ser Lab BR1000a Service monitor schematics  (Read 14776 times)

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Offline The Radio Shop

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Re: Com Ser Lab BR1000a Service monitor schematics
« Reply #15 on: November 18, 2015, 05:10:37 AM »
You sure were correct about that scope being different. It looks as if they made their own. Not really based off a particular design.
Those caps would cause it not to power up a trace. I would get those changed out and check components near by. See if anything else is out of spec.
Going to be around 2-3 k volts on the output.
Even the crt looks different.
Buddy kc4umo

Offline giboni

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Re: Com Ser Lab BR1000a Service monitor schematics
« Reply #16 on: November 18, 2015, 10:18:11 PM »
Hey. I need new glasses ! But I could see the difference ! Tomorrow will research & keep my fingers crossed. Name address on main unit. Probably the

 builder of the scope. Soooo is the read write switch the secret to using the frequency counter on the unit to check frequencies ? Is their anyway to check

the frequency output of the SG ? Unfortunately. Barely can hear the 1KHZ tone. Not sure if it is modulating the signal. However it does appear to be

 pretty close. I successfully used it to align the IF's of one of my Cobra 139XLR radios. This one is in my car. Whoo. A 3DB improvement. I added a

 ladder filter a few months ago. A few weeks ago repaired a factory defect on the receive. Still. A lot of patience until the unit decided to register 27.1850.

I re-capped this radio also. Sooo. If the SG keeps working. I will not beat it with a baseball bat LOL !

Where do I purchase these oil filled Caps ? The large I guess is 3KV .01uf . What about the small one ? All the other components look OK. Frankly. This

is out of my league. I need something more usable working. I found 600V oil filled for $3.95 each. Shoosh 3KV lets see off to Google !

Best John

Ah time for sleep. Why is oil filled so important ? What about this Tecktronix Scope part ? 5.95 4KV.


Offline The Radio Shop

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Re: Com Ser Lab BR1000a Service monitor schematics
« Reply #17 on: November 19, 2015, 06:36:11 AM »
Hey. I need new glasses ! But I could see the difference ! Tomorrow will research & keep my fingers crossed. Name address on main unit. Probably the

 builder of the scope. Soooo is the read write switch the secret to using the frequency counter on the unit to check frequencies ? Is their anyway to check

the frequency output of the SG ?

The read write switch is to store frequencies in memory. The display does not reflect the output frequency. Only the programmed frequency. Only way to read the frequency at the RF port is to connect a frequency counter.

Quote
Unfortunately. Barely can hear the 1KHZ tone. Not sure if it is modulating the signal. However it does appear to be

 pretty close. I successfully used it to align the IF's of one of my Cobra 139XLR radios. This one is in my car. Whoo. A 3DB improvement. I added a

 ladder filter a few months ago. A few weeks ago repaired a factory defect on the receive. Still. A lot of patience until the unit decided to register 27.1850.

I re-capped this radio also. Sooo. If the SG keeps working. I will not beat it with a baseball bat LOL !

Are you saying you can barely hear the tone in the radio or from the monitor speaker? Should be pretty clear in the radio under test.
Sounds like you did a good job on the 139.


[/quote]
Where do I purchase these oil filled Caps ? The large I guess is 3KV .01uf . What about the small one ? All the other components look OK. Frankly. This

is out of my league. I need something more usable working. I found 600V oil filled for $3.95 each. Shoosh 3KV lets see off to Google !

Best John

Ah time for sleep. Why is oil filled so important ? What about this Tecktronix Scope part ? 5.95 4KV.
[/quote]

Since the scope appears (from looking at your pictures) to be a quadrupled supply you will have to go back with this type of cap. I tried other caps in mine and it just will not fire.

At work then back to hospital tonight. Hoping for some time this week end. Will be only popping in and out using my phone.
Buddy kc4umo