I need someone to make me a one off pic.

A forum for the discussion of matters of a technical nature. All such activities are undertaken at the readers discretion and own risk. If you don't know what you are doing, don't blame us if it all goes wrong!
Post Reply
lbcomms
Super Member
Super Member
Posts: 239
Joined: 04 Oct 2015, 08:10
Location: Sydney, Australia

Re: I need someone to make me a one off pic.

Post by lbcomms » 06 Apr 2017, 09:22

speeddemon wrote:what would you use for a pll to replace old pll lc7120 chip
An MC145170 will replace almost any CB type PLL and is still available new, so that would be the logical choice there.

BUT: There are two buts.

1) Because of the high speed of the device (it can directly divide up to about 150 MHz!) the PCB layout is critical. You won't have too much success building the PLL circuit on perfboard, it will need a properly made (commercially fabricated) double sided board with a ground plane layer and good supply bypassing. See the recent thread with the Hornet SSB radio for an example of the correct board.

2) Before you even think about converting the PLL section, get the rest of the radio working 101% first, including the new micro.
If you have RF issues such as warbling or distortion when doing the PLL conversion, you will be able to be sure the cause is in the new PLL that way. Otherwise you'll never know if the cause of the problem was that or a dying 40 year old capacitor / other component / hackup by previous owner.
And have you ever done your atmega 16 pll02a ssb circuit mod with a 3digit 7segment common cathode display?
No, it was kept to two digits deliberately for two reasons. The first was to keep the stock appearance of the radio, but the main reason was to keep noise as low as possible.

There are enough pins on a Mega16 to provide "static" drive to the 14 LED segments - this means that the display voltages only change when the digit being shown changes. This is the same method used by mechanical channel switches like those found on the older style radios such as Cybernets.

More than two digits require the display to be "multiplexed". This shows the digits only one at a time, but fast enough so the human eye can't detect it. The display looks continuous, but it's actually changing 250 to 400 times a second. These current changes induce noise into the circuit which can be heard as a buzzing or hissing sound. Go any faster than that and the digits go dim and start to get ghosting on the unlit segments.

There are ways around it, such as using octal latch chips between the micro and LED drivers / resistors. That will let you multiplex at over 20,000 times a second, above the human hearing range and therefore silent. The downsides are the additional parts (two ICs per digit) and the additional wiring / PCB real estate required.

What are the three digits you want to show? A single LED could be driven static from one of the spare outputs and be used to indicate "zeros" or "fives", i.e. off for 27.595 and on for 27.590 MHz. The two stock digit display could then be set to show the channel number, or the KHz on Rx + MHz on Tx. For 27.595 in "frequency" mode it could show "27" on transmit and "59" on receive.
is there any changes in your code to make that type of display work?
Easy, once you know how you are going to wire the display to the micro...

Techquest
Super Member
Super Member
Posts: 141
Joined: 17 Oct 2011, 21:09
Call Sign: 29VLF125
Location: Carlow Ireland

Re: I need someone to make me a one off pic.

Post by Techquest » 06 Apr 2017, 21:02

speeddemon wrote:Hi ray gdday mate. ty for posting that ive been looking for that schematic for awhile now. cheers n 73's
Hi Speeddeamon your welcome
Techquest AKA Jedi
Av101 Astro Plane Old Imax n Loads of Radios
Mmmmmmmmmmm ADAMS n other Presidents

User avatar
speeddemon
Radio Addict
Radio Addict
Posts: 658
Joined: 30 Jan 2017, 03:58
Call Sign: speeddemon

Re: I need someone to make me a one off pic.

Post by speeddemon » 12 Apr 2017, 22:50

Hi sue where can get that mc145170 circuit board at ? I was thinking after I do your mega 16 pll02a ssb circuit mod was thinking to expand it with a 3 digit 7 segment diplay down the road for more frequencys and to display higher / lower channels readout ie -60/+180 channel numbers etc . Hopefully you back posting rest of your atmega 16 pll02a mod including the files for it soon as ive built a few prefboard atmega 16 pll02a ssb boards over the weekend and they are ready and waiting to be programed and waiting to be installed in my radios If I may ask you a question what modern chip will directly replace a pic16fc57 ? You and yours and everyone on the forum hav a gd easter Take care n cheers 73's

lbcomms
Super Member
Super Member
Posts: 239
Joined: 04 Oct 2015, 08:10
Location: Sydney, Australia

Re: I need someone to make me a one off pic.

Post by lbcomms » 13 Apr 2017, 08:07

where can get that mc145170 circuit board at?
That was made by prototype PCB service via a friend at uni. It was very much a prototype with a few design issues.

I'll get around to finishing it off one day, probably with an on-board 5V regulator and a small micro like a Mega8 to give the board parallel input. That will let it replace just about any parallel input PLL. Just need to find time to finish it off, but real work and other projects keep getting in the way. When it's done and I'm happy with the design, I'll post the Eagle and Gerber files so that anyone can get their own made.
for more frequencys and to display higher / lower channels readout ie -60/+180 channel numbers etc
Lots of ways to do that.

- Parallel octal latches (i.e. 74LS573)
- Shift registers (i.e 74HC165)
- Two wire bus extenders (i.e. PCF8574)
- Latching BCD display drivers (i.e. CD4511)

Any of those will add complexity and noise though.

I've only ever been asked for two digits here, it's enough to tell you where you are.
For example, "27" on Tx and "41" on Rx is enough to tell you the radio is on 27.415 MHz.
atmega 16 pll02a mod including the files for it soon as ive built a few
Once people have the parts and there are a some built (both here in T1 and elsewhere) I'll do the coding one step at a time.

First thing will be the classic "flash a LED", then some input like a switch to make it flash fast or slow. It'll then build up from there in stages, finishing at the final Cybernet 99 channel switch version. There is another very similar version to that, it uses the original channel switch with a Lo/Mid/Hi selector and a +10KC function.

By then, you should be comfortable enough with the principle to start customising it all for yourself.
what modern chip will directly replace a pic16fc57
By "directly", as in pin-for-pin and hex file identical, probably nothing. The devil is in the detail there. If it's a perfboard project you code yourself and it's no biggie to move a track or 3, then dozens of chips could replace it.

User avatar
speeddemon
Radio Addict
Radio Addict
Posts: 658
Joined: 30 Jan 2017, 03:58
Call Sign: speeddemon

Re: I need someone to make me a one off pic.

Post by speeddemon » 09 May 2017, 03:52

Hi sue will you be posting flash led soon?

lbcomms
Super Member
Super Member
Posts: 239
Joined: 04 Oct 2015, 08:10
Location: Sydney, Australia

Re: I need someone to make me a one off pic.

Post by lbcomms » 09 May 2017, 06:50

Haven't heard anything on this thread for a few weeks, I'm assuming the people haven't got all the parts yet. As soon as they post here that they have, and have made up their version of the circuit, then I'll go into the coding details.

Do you have the USBASP USB to AVR programmer yet, and have you built up a 5V regulator + Mega16 on perfboard with the non-programmable pins (such as power, ground, and so on) wired up?

User avatar
speeddemon
Radio Addict
Radio Addict
Posts: 658
Joined: 30 Jan 2017, 03:58
Call Sign: speeddemon

Re: I need someone to make me a one off pic.

Post by speeddemon » 10 May 2017, 21:24

Hi sue hru.? Gd i hope over there hope you and yours had a gd easter Holiday . yes I have two of the usbasp programers n avr software ready to go ive built three of your atmega 16 pll02a circuit on veroboards ready to be programmed ive been studying up on that usbasp programer and how to use it and the avr software over last few weeks sents I lasted posted . Hope you hav a gd mothersday . cheers n take care n 73's

lbcomms
Super Member
Super Member
Posts: 239
Joined: 04 Oct 2015, 08:10
Location: Sydney, Australia

Re: I need someone to make me a one off pic.

Post by lbcomms » 15 May 2017, 13:30

Hi, just got back tonight, will get to this one in the next day or two. Been away for a week, got a few minor things to sort out here first.

Can you post a pic or two of your version of the circuit? I'll help explain things a bit better, especially once it starts getting to the stage where you'll need to add a few parts and rearrange things slightly to work in different ways (such as converting a 40 into 120 low/mid/high band operation as opposed to a rotary encoder).

Also, let us know what radio / PLL you'll be hooking up to. uPD858 or PLL02A are probably the easiest to learn on if you have one. Get everything working perfectly on it before doing any channel mods...

User avatar
speeddemon
Radio Addict
Radio Addict
Posts: 658
Joined: 30 Jan 2017, 03:58
Call Sign: speeddemon

Re: I need someone to make me a one off pic.

Post by speeddemon » 19 Aug 2017, 22:04

Hi sue Its been awhile now looking forward to program these atmega8 pll02a circuits boards of mine over here. are you going to post any more of your tutorial ie flash led /code etc.? my ssb radios are all pll02a chassis ge/midland /tandy rackshack ive tryed to post pics this site wont upload so dont wait on me to post in this tread cheers n 73's

User avatar
speeddemon
Radio Addict
Radio Addict
Posts: 658
Joined: 30 Jan 2017, 03:58
Call Sign: speeddemon

Re: I need someone to make me a one off pic.

Post by speeddemon » 19 Aug 2017, 22:22

:ugeek: :geek: :D {bnghd} :thumbup: :wave:
You do not have the required permissions to view the files attached to this post.

lbcomms
Super Member
Super Member
Posts: 239
Joined: 04 Oct 2015, 08:10
Location: Sydney, Australia

Re: I need someone to make me a one off pic.

Post by lbcomms » 20 Aug 2017, 11:46

With Photobucket no longer suitable, use Tinypic to host your images, or post them directly onto T1 after resizing them to suitable dimensions (no more than say 800 x 600). If you don't have Photoshop or another image editor, resizing can be done online at http://resizeimage.net/ without the need to download or install software.

Some resized pics hosted on Tinypic from way back in April:

Image
Pinout of the AVR chip (ATMega16) used. A 5V regulator, the AVR, 3 diodes and a few passives

Image
The finished AVR board

Image
AVR board fitted to the radio

I've got a couple of "spare time" Cybernets here waiting for a similar conversion. The difference is they are using a regular 40 channel switch for input (i.e. not an encoder) and the owners want them to cover 4 bands: Low, Mid, High, and High high. They want the Aussie "gapless" band scheme.

Low: 26.615 - 27.005 (no skips or jumps)
Mid: 26.965 - 47.405 (standard FCC channel scheme)
High: 27.415 - 27.805 (no skips or jumps)
High High: 27.815 - 28.205 (no skips or jumps)

Changing this to the European "-450 KHz / + 450KHz" bands if you prefer that way is just a small software change.

If the radios aren't broad enough and the owners don't want to spend more money on them, they'll have to settle for Low/Mid/High or Mid/High/HighHigh.

If you want a step by step with pictures, coding, and any questions answered, continue the thread at:

viewtopic.php?f=53&t=53161#p477789

rather than this thread, which was for a conversion to a Uniden made radio.

I'll be doing this one as a spare time project, which might take a week or three to complete, depending on how much real work comes into the shop.

Post a few pics of yours and let us know how far you've got, i.e. do you have the USB programmer and have a Mega16 channel board made.

User avatar
speeddemon
Radio Addict
Radio Addict
Posts: 658
Joined: 30 Jan 2017, 03:58
Call Sign: speeddemon

Re: I need someone to make me a one off pic.

Post by speeddemon » 21 Aug 2017, 23:38

Hi sue have you seen or heared of this.? :geek: :ugeek: Also check out www cbh2000.de.. :thumbup: :wave: cheers n 73's
You do not have the required permissions to view the files attached to this post.

lbcomms
Super Member
Super Member
Posts: 239
Joined: 04 Oct 2015, 08:10
Location: Sydney, Australia

Re: I need someone to make me a one off pic.

Post by lbcomms » 22 Aug 2017, 09:02

Not that exact one, but it's a circuit that was common down here in the late 80's and early 90's when CB was more popular (before my time in radio!).

An EPROM controlling an MM55126N PLL synthesizer chip - similar to the PLL02A but with a 5.12 MHz output and on-chip reference oscillator, but one less programming pin. Needs a downmixer as the dividers are limited to about 3 MHz. They found homes in the uPD2816 and uPD2824 radios (such as Cobra 29 and Realistic TRC-451) giving them additional channels into the low 28 megs range.

Very old technology by todays standards (the chip in the picture has a date code of December 1981) but works well.

Limitations: Can't be used in radios without a downmixer, the programming has to be done before being soldered onto the board, can't be erased for reuse / alteration, and components are likely unobtainable from the big suppliers (RS, Element14, Digikey, Mouser).

Post Reply

Who is online

Users browsing this forum: No registered users and 2 guests