SBE Console II off freq

[titan7]

Okay so I have a couple SBE Console II radios, I pulled the 11.700Mhz crystal and installed a 12.100Mhz in its place, this gave channel 36,37,38, and 40 instead of 1,2,3,4. I worked great for on radio but the other is a little off freq. on 38 LSB, and the clarifier is maxed to the left. So, aligninment or can the clarifier be opened like a 10kc slider so I can get on frequency?

Thanks

[2600]

There is a trimmer capacitor for each crystal. The one for the channel 1-4 crystal socket is "CV6" in the schematic.

There is one empty spot in the long crystal socket, next-to-last position at the inboard end of the crystals. CV6 is just to the rear of that gap.

No telling if it will let you put that crystal on frequency, but there's only one way to find out. If it won't turn far enough, this is the only way to tell.

You may find that a metal-tipped tool causes the frequency to change when you touch the slot in the trimmer cap.

Finding a nonmetallic tool that size can be a challenge. When you see how much error you get from touching the trimmer cap with the screwdriver blade, just set it that far the other way while it's touching. It can be "fudged" on frequency this way.

73

[titan7]

Thank you, just a quick question, I assume those trim pots are adjusted for the frequency of that crystal. So, would I be closer to frequency by putting the 12.100Mhz crystal in place of the 11.950MHz crystal instead of the slot for the 11.700Mhz crystal? I would assume since the trim pot for the 11.950 is a lot closer to 12.100mhz than 11.700 is to 12.100.

Will the .250 MHz closer make a difference at the clarifier? I realize I would only get ch. 36, 37, 38, in place of Ch. 21-23.

Again not sure if this works the way I think itwould, i.e. the trim pot relationship to the clarifier.


Thanks Nomad, hey Dino Darling said to give you a shout out.

[2600]

Every manufactured product will be imperfect. The tolerance for a standard hardware-store nut and bolt can be measured, but won't matter if they are close enough.

Mass-produced crystals are made 'close enough' and the trimmer cap is there to compensate for that tolerance error.

The exact error in any crystal won't be the same from one to the next. Switching that crystal to another socket might reduce the error, might make it worse. Only one way to find out.

Just wish there was a clear map from each crystal socket to the trimmer cap that controls it. Had to look at the schematic to identify the one that adjusts the crystal in the channel 1-4 socket.

Way cool to hear from Dino. Been a while. Good to find he's still doing okay.

I don't have a setup on hand to increase the clarifier range for that radio. Doesn't mean you can't, but it won't work the same way it does in a 40-channel radio.

A 40-channel radio relies on one crystal that's connected to the clarifier. This radio connects the clarifier to a different crystal every four channels.

That trimmer cap will set differently for each different crystal that's plugged into that slot on the crystal socket strip.

73

[titan7]

Thanks I appreciate you taking the time to add very helpful information. I swapped the position of the crystal but of course nobody on 38LSB tonight, I mean nobody. Will see if I can talk to somebody to see it if helped, if not I found a local tech, Chris, at the Radio Shop in Ontario who said he can adjust it for me. Figured i

[titan7]

Thanks I appreciate you taking the time to add very helpful information. I swapped the position of the crystal but of course nobody on 38LSB tonight, I mean nobody. Will see if I can talk to somebody to see it if helped, if not I found a local tech, Chris, at the Radio Shop in Ontario who said he can adjust it for me. Figured i

[Sandbagger]

Sept 10, 2018 20:08:07 GMT -5 titan7 said:

Okay so I have a couple SBE Console II radios, I pulled the 11.700Mhz crystal and installed a 12.100Mhz in its place, this gave channel 36,37,38, and 40 instead of 1,2,3,4. I worked great for on radio but the other is a little off freq. on 38 LSB, and the clarifier is maxed to the left. So, aligninment or can the clarifier be opened like a 10kc slider so I can get on frequency?

Thanks

That radio does not have an easy way to extend clarifier range the way some other radios could. I used to simply swap out the clarifier circuit for a simple variable cap with about a 5-6 uH choke in series. But unless you're technically inclined, I wouldn't attempt it. And although I've never tried it, you might get away by increasing the value of L17. It's essentially the "L" in LC circuit (D23 being the "C"). The fear I would have is that what you would gain in range, you would give up in stability.

[titan7]

Thanks for all help, I am just gonna have the shop check the alignment and adjust the trim pot for 36-38. Also them give it a once over, get rid of noise in the pots. Thoughts of having the power cord change to a grounded 3 prong, and having the Flat caps on the AC line replaced?

I will pick up a modern radio so I don’t really want to mod this one.

[Sandbagger]

Sept 12, 2018 20:14:22 GMT -5 titan7 said:

Thanks for all help, I am just gonna have the shop check the alignment and adjust the trim pot for 36-38. Also them give it a once over, get rid of noise in the pots. Thoughts of having the power cord change to a grounded 3 prong, and having the Flat caps on the AC line replaced?

I will pick up a modern radio so I don’t really want to mod this one.

I'm of the opinion that you keep a vintage radio stock and enjoy it as it was made. Then, if you want a fancy radio with all the bells and whistles, you buy a new one with all the mods built in.

[cbrown]

Agreed!

[238]

That is cheaper an better in the long run.

[titan7]

Sept 11, 2018 0:17:52 GMT -5 2600 said:

There is a trimmer capacitor for each crystal. The one for the channel 1-4 crystal socket is "CV6" in the schematic.

There is one empty spot in the long crystal socket, next-to-last position at the inboard end of the crystals. CV6 is just to the rear of that gap.

No telling if it will let you put that crystal on frequency, but there's only one way to find out. If it won't turn far enough, this is the only way to tell.

You may find that a metal-tipped tool causes the frequency to change when you touch the slot in the trimmer cap.

Finding a nonmetallic tool that size can be a challenge. When you see how much error you get from touching the trimmer cap with the screwdriver blade, just set it that far the other way while it's touching. It can be "fudged" on frequency this way.

73

Nomad,
So adjusting this CV6 pot will adjust the clarifier for that crystal bank? So this will center my clairifier for the channels in that bank with are now 36,37,38,40. I assume without a freq counter I should be listiening to somebodywhile adjusting this?

[2600]

No, CV6 is connected only to that one crystal socket and none of the others.

73

[BBB]

SBE Console II... the Brady Bunch CB Radio

[Sandbagger]

Oct 8, 2018 18:14:44 GMT -5 BBB said:

SBE Console II... the Brady Bunch CB Radio

View Attachment

That's a Skeeter trademark...... But I like the looks of the Console II