Transmission1

Don't get me wrong Paul, I'm not knocking it, good on you for taking on a project, that's a big part of the hobby for some, I'm a lazy (stupid) operator and go for the easy option as I don't have the technical knowledge or skills these days. But I have also taken on a project that has ended up consuming a big chunk of my life and bank account and at the end have realised it would have been so much easier and cheaper to get something that already did the required tasks in the first place, but good luck mate, I hope it goes well and you keep this thread topped up with your progress. Howard.

mastercare wrote:29.200-29.300 usb and fm repeaters 29.550-29.700

That is doable with the second radio just by changing out one crystal and adding a wire or two to the PLL area. Once you can tell us what the crystal and PLL chip values are, I'll go into more detail. You might have trouble centering LSB, but that won't be an issue on 10 meters.

The picture with the extra board is for the Montgomery Ward. That one will have gaps in the channel coverage and won't have FM, so probably best to concentrate on the Intek radio first, especially if you want the repeaters. The Montgomery Ward can have FM fitted, but it's fairly involved (expensive) to do...

Hi all
no offense taken Howard, i know where u coming from a long time ago i spent money and far too much time on a wide screen tv i got for peanuts, at the time it was the dogs round bits...but never got anywhere too much damage, wife gave me load stick over it,,so i get your point. Hi lbcomms yes the Montgomery ward is on hold, im going to concentrate on this intek. first...still not arrived yet...keep you all informed..
once again thanks all, its my birthday today aswell...byeee...

happy birthday m8

Hi Guys
well the intek cb arrived just over a hour ago.the pll chip is motorola MC145106P there are 2 crystals one next to 4 coils near ribbon to front it says REC then 15.380 underneath there is the standard 10.240 mhz crystal and in the middle at front another crystal 10.6975mhz the 15.380 is hard to read last digit could be wrong but think its right....hope this is all you need....
ill enclose some photos

Hi guys
ok photos seem ok...anything else needed let me know...
many thanks agn
paul

mastercare wrote:the pll chip is motorola MC145106P

With the radio turned on and receiving (any mode) on channel 1, measure the frequency at pin 2 of the PLL. Repeat with the radio on channel 40.

You should have something in the range of 0.7 MHz to 3 MHz for most variations of that chassis.

What two exact frequencies did you get with the radio on 1 and 40?

Hi thanks lbcomms i will do those tests u mention, the freq counter i got is a Victor VC3165 High Resolution Counter hope that will be ok i will put a small cap on the lead to test those pins. hope theres enough to drive it..ill get back to u soon as i have some results,
thanks agn
paul

You should have a volt or two of RF energy at that pin, the counter goes as low as .03V so you should have no trouble getting a reading. Only thing that might cause grief is circuit loading stopping the PLL downmixer from working, you might have to add a bit of resistance at the measurement point, or better still use a 10:1 probe if you have one. Good luck...

hi lbcomms
yes i was thinking of loading, i could use the scope lead i guess that has 10>1 probe on it...well we after a freq i guess this is the vco after mixing...
ok ill let you know...
thanks agn for helping me through this project, its all good learning aswell...
cheers paul... sleep well i guess its just after midnight down under lol
byee

Hi lbcomms
good morning i think...
ok first of all ive just found that this cb goes from ch 1 > 34 not 40
the readings if these make sense to u...
are ch1 = 0.916 MHZ
ch 34 = 0.904 MHZ
also for interest ch 23 reads 1.203 MHZ
hope this makes some sense to u....
cheers
paul

Crystal will most probably be 15.360 MHz, not 15.380.

VCO = Actual - 10.695 MHz
Therefore channel 1 VCO = 16.270 MHz (26.965 MHz - 10.695 MHz)

PLL = VCO - Crystal
Therefore channel 1 PLL = 0.91 MHz (16.270 MHz - 15.360 MHz)

PLL has 254 x 5 KHz steps, i.e. 1.27 MHz coverage.
Highest actual channel frequency will be 28.235 MHz (26.965 MHz + 1.27 MHz) using the original crystal.

Therefore, to get up to where you want, you'll need to change the crystal.

You want to cover 29.200 - 29.300 and 29.550 - 29.700, so you'll need a starting point (PLL 0.91 MHz) between 29.0 and 29.2.

29.0 = VCO 18.305 MHz. Crystal = 17.395 (18.305 - 0.91) to set this frequency onto channel 1.
29.2 = VCO 18.505 MHz. Crystal = 17.595 (18.505 - 0.91) to set this frequency onto channel 1.

The crystal you'll need is one anywhere from 17.4 to 17.6 MHz, have a look through your old boards, parts boxes, ask around your mates, or pop a wanted notice on the forum. If you can grab a few slightly different ones then do so, not all will allow the radio to centre to "0" or let the clarifier work correctly.

Once you've fitted that, you will first need to relock the VCO, then completely realign all the RF and mixer stages.
Then it's an easy PLL trace mod (rewiring or adding a couple of switches) to get full coverage from 29.200 to 29.700 MHz.
Will explain that in more detail once you have the crystal...

If you can't source a crystal just use an SI5351 and Arduino to generate the frequency you need, I can write the software for the Arduino for you if you need help with the coding and provide schematics etc - I am using one of these in my homebrew VHF SSB rig which I am currently building and they are very stable.
You simply tell it what frequency you want and it will generate anything between 8KHz and 160MHz no problem, if you were feeling adventurous you could replace the whole PLL/VCO system and gain a lot more functionality and band coverage for less than £20.

Cheers

Rob.

Hi libcomms 2e1llp
well Ive been blown away, libcomms produced all that from 3 freqs i took off the pll chip, i found my little cheap chinese meter read the same so i managed to double check the freqs, this ardurino and s15351 board sounds what i will prob need, but as stated i will look through my old crystals see what ive got. it seems ive got alot work ahead on this, but i will have a go, so far im keeping up with all your guys help...
get xmas over and ill have more time...
thanks agn guys
paul

Hi Rob
just been looking at the s15351 board and the arduino im not into programming at all i notice arduino uses a c++ code but what is this board doing in the application im wanting i understand the s15351 can generate various freqs or does one board control the other, im a bit confused?
cheers
paul