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Author Topic: Siltronix 1011D question  (Read 285 times)

WB8PFZ

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Siltronix 1011D question
« on: November 08, 2022, 05:30:04 AM »

I am trying to find out the VFO frequency of this radio. Can someone point me in the correct direction. Thanks Mike
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KB1GMX

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Re: Siltronix 1011D question
« Reply #1 on: November 08, 2022, 06:41:00 AM »

its easier if you have the manual.... RTFM

the VFO output is rx frequency -5.500 = xxxx mhz give or take.

So 28.000mhz is  about 22.5mhz LO and VFO (Q1) runs at 1/2 that.


Allison
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WB8PFZ

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Re: Siltronix 1011D question
« Reply #2 on: November 08, 2022, 10:03:01 AM »

So the VFO operates at half the frequency it needs to be. Where does the doubling take place? In the buffer? What a poor manual.  Would have been nice if the block diagrams were done better.
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WB8PFZ

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Re: Siltronix 1011D question
« Reply #3 on: November 08, 2022, 01:37:31 PM »

So checking the frequency that goes to the digital readout on the back of the radio, I show 2 x  what the VFO frequency should be. Not sure why that is. The radio seems to receive the CB band but not the ham band.
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AC2EU

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    • McVey Electronics
Re: Siltronix 1011D question
« Reply #4 on: November 08, 2022, 04:51:20 PM »

When you say VFO, are you referring to the raw heterodyne tuning  ( 5mhz?)or the actual receive frequency.

THose radios were a favorite of CBers, so who knows what they might have done. There is a coil inside the VFO osc that gets messed with.
Maybe the fixed trim caps too.
There was some mod out there that did something the CB folks all tried to do and made a mess.

KB1GMX

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Re: Siltronix 1011D question
« Reply #5 on: November 11, 2022, 11:32:18 AM »

the 1011 has a VFO its solid state (Q1) and there is a solid state buffer (Q2)
That fees osc buff a 12BA6, what dies it do 2x multplier plus pumping
the signal up.

As manual go its not at all bad.

The tuning system runs at about 5.5mhz lwer than the IF of 5500khz.

Actually the "coil" didn't have to be messed with as it tuned 11M.
The messing part was the freebanders gowin well beynd the VFOs
nominal tuning.

The later D version has an added jack for frequency counter option
and it sampled the Mixer injection frequency not the VFO direct.
Most that had the counter for it added the jack easy mod.

Had one then, have one now.  Also have the counter.


Allison
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WB8PFZ

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Re: Siltronix 1011D question
« Reply #6 on: November 12, 2022, 02:22:42 PM »

I had some time to play with the radio today. With slight adjustment of the variable caps in the VFO compartment I was able to get the VFO frequencies where they should be. The data I have found says the VFO should operate at 21.45 and 23.0 mhz depending on what band you are on. Not sure about the next stage doubling the VFO frequency. More to trouble shoot. Baby steps with this old radio. Mike
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KB1GMX

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Re: Siltronix 1011D question
« Reply #7 on: November 15, 2022, 08:48:05 AM »

Data you have found...

That suggests you don't have the manual (from on line).
There is no shortage of info on that radio from the manual itself.


I have the manual and the radio so its not foreign to me.


Allison
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N4ATS

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Re: Siltronix 1011D question
« Reply #8 on: November 20, 2022, 03:53:28 PM »

Simple , plug in a frequency counter to the back jack marked Frequency Counter. This LO output mimics the VFO frequency for counter conversion
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WB8PFZ

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Re: Siltronix 1011D question
« Reply #9 on: November 21, 2022, 07:04:57 AM »

My last post says I have the VFO operating correctly. On to the next stage.
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