5 band Silver Franklin and the EPT360011Z pcb.

[cb4ever104]

Hi All .

I've almost got to grips with this EPT360011Z board . However , I am a bit stuck with the band switch on this Franklin . There are 2 variants of the 11Z board . Radios with 6 bands have 2 crystals . Each crystal gives 3 bands . Easy . However the Franklin uses the one crystal and supposedly has 5 bands , but there are still only 3 wires from the main pcb to the band switch . At least there are on mine . Band A has nothing connected (91-135) , so that plus the 3 only gives me only 4 bands ? To complicate matters , the component numbers on the schematic for the Franklin "A" don't match my 11Z board . That schematic shows 4 wires from the band switch to the pcb , but there are physically only 3 . So I seem to have missed something regarding the mysterious 5th band ?

I've added a couple of diagrams below . The blue dots are the 8 channel selector wires . The 3 orange dots are the band switch wires . The wire to R140 (VCO) is further up the board .

Capture_0014.jpg

Here you can see the 4 connections from the band switch to the pcb . The traces for bands B , D and E have been rubbed out of the scematic , but you can see where they supposedly connect to the diode matrix .

Capture_0015.jpg

Help !


Thx

Sammy

[14CS06]

Hello Sammy

Please look at this link

http://pbelaire.free.fr/fichiers/President_Franklin.pdf

Different PCB with one PA or two PA

Mods Franklin



@+
Claude

[cb4ever104]

Hi Claude .

I know there are 3 versions of the Franklin . Mine is the silver version with 1 PA , and 2 antenna connections . The problem is that none of those 3 schematics actually match the Silver 11Z Franklin . All of my diode matrix values are D4X to D5X . None of those diagrams have the correct values . The closest one is the Franklin "A" , but as I have already mentioned the component numbers don't match . I have a correct diagram of the solder side that I posted above (with the dots) that does have the correct values , but I don't have the correct schematic to match it .

I really don't understand the other diagram you posted . I have the 3 "band" wires coming from 10 , 11 and 12 . That's fine . I also have the orange wire from 13 , which adds capacitance to the VCO for a couple of the bands . That's fine . The problem I have is that I don't see how I can get 5 bands that cover 26.065 to 28.305 with this configuration ? The translation of the description doesn't help either "solder a strap reunite to their son placestous these sodas that are on the brown wire" .

Sammy

[cb4ever104]

The purple/violet wire in the above diagram is one of the channel selector wires . Is it not ?

[14CS06]

Hello Sammy

Please look at the schematic President RONALD 1





For "The purple/violet wire in the above diagram is one of the channel selector wires . Is it not ?"

I do not know

@+
Claude

[cb4ever104]

Thanks Claude .

Maybe I'm going blind , but I can't see the BAND switch marked on the Ronald diagram ? I'll keep searching for it .

Sammy

[cb4ever104]

All I really need to know is where the purple (E) wire from the Franklin band switch goes on the main pcb .

[14CS06]

Hello Sammy

Please look at this schematic of Excalibur SSB



@+
Claude

[cb4ever104]

Thanks Claude , but the diode matrix is different on the Excalibur . It's got the same errors as the Franklin A diagram with the wrong diode numbers . Also 4 of the 16 diodes in the Franklin are connected to the channel selector lines like in the Ronald diagram . That only leaves 12 diodes for the 4 bands (B to E) . 4 are used on each one , so there's something funny going on somewhere with the E band as I'm missing 4 diodes . Anyway , I've got the radio working on bands A through D at the moment . I'm going to have to leave the E band until I can find out where the purple wire goes to .

Can you translate this Claude ?

Capture_0016.jpg

I think some of the words have been joined together .

Thanks again for your help .

Sammy

[14CS06]

Hello Sammy




solder a strap

solder in their place every wire that are welded to the brown wire

translate google

@+
Claude

[cb4ever104]

Hello Sammy




solder a strap

solder in their place every wire that are welded to the brown wire

translate google

@+
Claude

Hi Claude .

Do you know what this diagram/modification is for ?

Sammy

[14CS06]

Hello Sammy

Sorry
Just find this change but without explanation
I added this to the wiring



@+
Claude

[cb4ever104]

Hi Again .

Well . I'm going to post my findings on this radio and this board . Before I start I'd like to say that as far as I can see there's no way that you can get 5 bands from an EPT360011Z pcb Franklin , without modifying it . You can get 3 bands with one crystal , or 6 bands with both fitted . Not 5 . There are 3 diagrams on the web for the Franklin . None of them are for the 11Z . There's a diagram marked "Franklin A" , but it's the EPT360010 pcb . I'm almost 100% sure that all 5 band radios use the EPT360010 pcb . The only correct diagram I've found for the 11Z is for the RONALD . It's the correct 11Z , with both crystals fitted .

Anyway . There are 2 versions of the EPT360011Z pcb . One with one crystal (Franklin) and models with 2 crystals (3900,Ronald etc.) There are 16 matrix diodes (D4X to D5X) . 4 for band "B" , 4 for band "C" . 4 are on the channel selector line , and 4 for the channel 9 feature . There are only 2 wires that go to the band switch . These are marked "11" (Band B) and "12" (Band C) . "13" goes to the VCO and "10" is the CH9 . Band A (26.065) is generated by passing the basic channel selector output (91-135) to the binary adders and PLL . Band B is +45 , and band C is +90 .

If you have a radio with both crystals then you will have a HI/LO switch to switch between each 3 bands . I haven't seen a twin crystal radio that actually has the 6 bands on a 6 way band switch .

And that's about it . I'm going to do a diode/binary adder mod on my Franklin to get bands D and E . I do have another radio here with both crystals in it that I could use , but it's a lot of work . Adding 8 diodes is a lot easier .

Anyway . That's what I've found out over the last week . I hope it helps someone .

Capture_0018.jpg

Sammy

[cb4ever104]

Just updating my own post . The diode mod won't work completely . Well it will , but band D gets a bit messy as I need to try and switch in pin 9 of the MC145106 PLL half way through the band . So , I've decided to go ahead and do the "clean" mod and add the 2nd crystal which will give me 6 bands , instead of 5 . Hopefully I'll be able to have them all on the one 6 way switch . I'll need to have a good look at the above diagram and figure it all out first . All good fun

Later !

S,

[cb4ever104]

I ended up having to buy a 4 pole 6 way switch , as the 2 pole one's that I had wouldn't do it .

One pole has to jumper bands A to D , B to E and C to F .

Another pole has to give +8V to the R140 VCO section on the LOW (A,B and C) bands .

And another pole has to ground each unused local oscillator crystal stage .

Once I finish this (and repair my Yaesu 707 , and do my TRC-449 channel conversion) , then I'm going to do this 6 way band switch conversion on my SS3900 , which also has the 11Z pcb .

More to follow ...........

S.