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president Grant pc-999ae

Posted: 21 Nov 2016, 19:15
by 4a0026aleks
Hello ALL! please help to remake the radio, the President GRANT CLASSIC to coarse worked, plus or minus 5 kHz from the center

Re: president Grant pc-999ae

Posted: 22 Nov 2016, 10:32
by dt307
hi to get a grant to do the zeros there is a few ways

replace pll (hard) the way i do them

add inductance to the varactor after unlocking the clarifier or coarse (easy but about 7kc max total slide)

rip most of the circuit out and copy a 148 one (hard and she will raft after)

best way for you snip 2 jumpers and wire a switch
GRANT10_zps7adefedb.jpg
viewtopic.php?t=38742

been covered before .....try the forum search :roll:

Re: president Grant pc-999ae

Posted: 26 Nov 2016, 08:22
by cb4ever104
The above mod only works on SSB . If I ever get enough time then I'd like to dig a bit deeper into this subject as well . I'm sure there must be a way to get +/- 5khz out of the COARSE control on the later Grants .

Sammy

Re: president Grant pc-999ae

Posted: 26 Nov 2016, 14:16
by Mudslinger
Doesn't the 5KC mod also shift the radio up on USB and down on LSB or something like that?

I had a Grant that had been modified like that and it drove me around the bend.

Re: president Grant pc-999ae

Posted: 26 Nov 2016, 14:21
by dt307
when i get time m8 i will look into it but as i said from when i done one last even giving ott voltage on the varactor and some padding with inductance it wont go 10kc to do -/+5kc

copy the gtldx circuit is an option but a lot of work and the rig will start to raft

i did get a grant to slide 12kc but the way i did it was rough as hell and i rather not explain as it turned the rig into a raft

its why i go the module pll route you get 5kc on a switch and uk 1-40
its cleaner less pain and it stable on frequency 100hz drift max but the cost might be an issue to most

the jumper switch method is prob best but i dont like it and as you say its only ssb

Re: president Grant pc-999ae

Posted: 27 Nov 2016, 09:07
by cb4ever104
dt307 wrote:copy the gtldx circuit is an option but a lot of work and the rig will start to raft
The first problem is that I don't think there's a diagram for the AD/E Grants with the coarse . So it'll be a bit more work . I'm sure that Nick has commented on this subject a few times in the past , but I can't remember what he said . There are a few methods mentioned in that other thread about replacing those 2 diodes . So it might be worth a shot .

Sammy

Re: president Grant pc-999ae

Posted: 27 Nov 2016, 14:42
by dt307
what i did is change the diode for ones in a cybernet uk and a 4.7 inductor in series
added a crystal in parallel with the orignal this allowed for more pull ability (the grants i do only use one of the crystals for bands the other and inductors are rendered not used as all the bands are generated from a single crystal)
9v on the hot side of the rit, other was grounded

this got me 12kc of slide but wasnt linear ie not -/+ 5kc from center it was more one way than other .
different value resistors were used on the ground side and also different feed voltages used but couldnt get it as i wanted
frequency drift was noticeably worse.

the version of grant with the dual pot is just that it still wont shift like a cobra
i gave up on the idea as the switch method is a good rough and ready approach

now if i do one i just unlock the rit pad the diode a little to get some more slide
put a pll module in with 5kc jump.as long as she slides -/+ 3kc its good to go

but like you say im sure nick has modded one from 148 parts but cant comment on how much work and what the end result was

Re: president Grant pc-999ae

Posted: 27 Nov 2016, 16:28
by cb4ever104
I've only got one Grant anyway , My boxed "Classic" . I did the jumper mod (as I do on them all) on the RF/MOD switch . And +10khz on the BRITE . I don't need the UK40 , so that really gets me all the channels within the 3 bands . It would be nice to know exactly why it won't go +/- 5khz , but I'm not prepared to butcher my radio to find out :)

S.

Re: president Grant pc-999ae

Posted: 27 Nov 2016, 20:56
by dt307
sorry hijack thread
@harakiri
SPDT-relay-diagram.jpg

Re: president Grant pc-999ae

Posted: 27 Nov 2016, 22:07
by harakiri
dt307 wrote:sorry hijack thread
@harakiri
SPDT-relay-diagram.jpg

Thanks dt307 .
Blame me for the hijacked thread. Sorry for that folks.

Re: president Grant pc-999ae

Posted: 20 Nov 2019, 12:04
by 163TM847
I know this is an old thread but i thought i may add some info too it regarding unlocked clarifier shift for the PC-999AB with clarifier only, I have done a similar mod to the Grant black and classic which has dual fine/coarse from factory but i dont have the information to hand, But it will require swapping the 15.4525 for a UNI 15.4500 which are not easy to find.

This will only work on Mid and High unless you do the same mod to the low band circuit, You will also need some parts pulled [preferably] from a scrap MK1 PC-879 148/360, I have done this many times and it works quite well

President Grant PC-999AB getting more slide from unlocked clarifier with original 15.4525

Remove D45

Remove Blue wire from clarifier and connect directly to ground

Remove Grey wire and connect to constant 8v [I am typing this from memory, So if unlocked clarifier works backwards simply swap blue and grey around]

Replace L25/26 with LB209s [From a scrap MK1] L27 [LSB] in a PC-999 is usually an LB209 from factory, If it isnt then replace this also.

Replace D44 vercator diode [With veractor from a scrap PC-879]

Replace C234 8pf to 15pf [This is important, This cap is located by the side of L27 LSB inductor]

Once done put the clarifier to centre and realign L25/26/27 and you should now get roughly + and -7 AM/FM, + and - 6 USB, Generally LSB always has more slide than USB so i have never actually checked the amount.

As mentioned above there will now be some drifting, So align once radio has had a good warm up, But with just an unlocked clarifier you shouldnt really notice it.

Hope this helps.

Re: president Grant pc-999ae

Posted: 22 Nov 2019, 18:47
by cb4ever104
Black Spirit wrote: 20 Nov 2019, 12:04 Hope this helps.
Thanks for sharing this info Nick .

Sammy

Re: president Grant pc-999ae

Posted: 04 Dec 2019, 16:56
by slamjam
I'm in process of ordering a board from Maurer for one of my grants. It's going to be L/M/H/UK +5 +10. Does anyone know how I'll wire the band switch when it arrives? Can the 3 way be converted to a 4 way switch? If not I might just wire the original 3 way as M/H/UK ?

Re: president Grant pc-999ae

Posted: 05 Dec 2019, 09:05
by cb4ever104
If it's like the other modules then you'll have 4 wires off the supplied pcb header . Earthing each wire will give you the desired band . So , as you say you'll need to rewire your current one as that switches in +8V to each band . instead of that you'll have earth as the common and the 4 wires from the header will be the output . Don't think I've ever modded a Grant band switch , but if it's the same one that's used in the 148 (it probably is) , then you can make it 3,4,5 or 6 bands . There's a document on here somewhere that shows you how to do this . I don't have it on this PC . You'll need to remove the back plate , and then move some of the internals to make it 4 way . Don't forget that you'll also be able to ground both +5 and +10khz wires to give you +15khz . That'll allow you to reach those hard to reach places .

Sammy

Re: president Grant pc-999ae

Posted: 07 Dec 2019, 07:57
by 4a0026aleks
hello everyone add to this topic. I have long since remade my President guarantor classic. I put DS + Arduino . everything works very well