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Hi does anybody know how to increase the slide for 5+ khz either side of the 12'o clock position on a Stalker ST-9FDX??, Mine currently only slides about 1 khz either way & it would be nice to be able to get on the zero's,as it already has a 10 khz flicker switch for me to get on the alpha's, the pc board number is pc-893

Change the Varicap diode d32 to some think like BB809 and unhook one end of d33.

James.

James Unit 198 wrote:Change the Varicap diode d32 to some think like BB809 and unhook one end of d33.

James.

Hi James, have you carried out this modification yourself to a 9fdx? & did it work o.k & how much swing did you get out of the clarifier?? also i was looking at the schematic here

http://www.cbtricks.com/radios/teaberry ... dx_sch.pdf

& to me d31 looks like the varicap diode your help is much appreciated,cheers,Shaun

Shaun,
Your right D31 is the varactor diode. You could also try a ITT410 out of an old Cybernet multimode radio but 10KCs of total slide, i don't think so.

zodiac wrote:Shaun,
Your right D31 is the varactor diode. You could also try a ITT410 out of an old Cybernet multimode radio but 10KCs of total slide, i don't think so.

cheers zodiac, just looked inside her, & d33 has been removed & d31 is present,think its still the original varicap diode,think i shall have to do a bit of websearching for the 2 replacements you guys have mentioned for the varactor/varicap diode d31 & see how it goes i would be a very happy chappy if i could get onto the zero's with her, but i do realise its a tall order,cheers again guys & i shall let you know how i get on with it

just been talking on another forum about this mod & a guy said this super diode would increase the slide

http://www.firecommunications.com/trdbase/mv1404.pdf

but they are not cheap..

http://cgi.ebay.co.uk/DIODE-MV1404_W0QQ ... dZViewItem

You do not need a so-called super this is just some one trying to make some wage out of you. The varicap diodes SVC251 and BB809 are diodes with a hi C/R, you could call them a super diode but they are just a varicap diode.

This is an easy mod; you need to change 3 components, Remove D33. Change varicap diode d31 to SVC251 or BB809. Change R231 from 6K8 to 3K3. Remove R168 and connect the top end of the Clarifier control (Looking at my diagram) to the always 8-volt line, you can pick this up at the Collector of TR39. Change R187 to 470uH choke.

You will need to re-alignment of the PLL section.

If you have completed all of the above, you should have ? 5 to 6 KHz.

This mod has been try and test on over 35 radios.

Rick wrote: Change R231 from 6K8 to 3K3.

Hi Rick do you mean change R231 to a 3.3 k ohms?

If you are work with old money then yes, 3K3 is in old money 3.3K; we do not use the full-stop or period (USA) as this can easily lost on old photocopied diagram, and this way it is easy to read.

LOL! Cool I am going to buy/scrounge all the bits i need tonight, so after completion it should slide 5-6khz either side of the 12 'o clock position so then i can get onto the zero's ,yes??

Rick wrote: Remove R168.

do i replace this with a jumper or just leave the 2 holes vacant??

It is easy just follow my advice.
Remove R168 and connect the top end of the Clarifier control (Looking at my diagram) to the always 8-volt line.

Look at my diagram and will see where R168 is connect to.

If you do not understand it would be best to get some one which doze.

Hi Rick, i did'nt realise that schematic was yours,well done,best & the easiest schematics to read Had a look inside her & R168 has already been removed along with d33.So that says to me somebody has done half of a job trying to get swing on this 9fdx before, think i can manage to do what you have explained to me Cheers Rick & i will let you know how i get on

Rick wrote: This is an easy mod; you need to change 3 components, Remove D33. Change varicap diode d31 to SVC251 or BB809. Change R231 from 6K8 to 3K3. Remove R168 and connect the top end of the Clarifier control (Looking at my diagram) to the always 8-volt line, you can pick this up at the Collector of TR39. Change R187 to 470uH choke.

What is the point of changing R187 to a 470 uH choke?

Regards,

Brian.