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Nobody is interested in PLL?
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hi and greeting from UK.
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I must have missed an earlier post on this .... All developments of the unit I am watching but at the moment other club matters have slowed my progress ..it happens when you take on the HON SEC. post of a club ... I will look at the files soon and thank you for placing them in the project. Charles G4VSZ -----Original Message-----
From: BITX20@... [mailto:BITX20@...]On Behalf Of eb7hpm Sent: 08 July 2005 08:43 To: BITX20@... Subject: [BITX20] Nobody is interested in PLL? Sorry, but realy nobody is interested in my PLL project?? It is MC145170 and 16F628 based. It is working 100% in BITX. I post the schematic, photos and the C source code of working beta in the files section. Any coments? Perhaps, my bad english is the problem? Greetings Manuel EB7HPM/EC7ALV Yahoo! Groups Links |
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Hi Manuel,
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perhaps, it is because that topic should be in the huff and puff yahoo group? Chris. Sorry, but realy nobody is interested in my PLL project?? |
¿ªÔÆÌåÓýHi Manuel,
????????????????
Just had a quick look at the photo's and the C-Code source, congratulations,
excellent work, I will have a closer look as soon as I have some free
time,?
my BITX20 is using a PLL circuit with LCD?display? frequency with
100 hertz steps, designed?by my countryman VK6BRO?Richard
Hosking.??
???? Thank you for your contributions, good luck with development of the other features and have lot's of fun. Cheers and 73 ?Alf??
VK2YAC |
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I want to contribute the comunity with my work and that you not
missed the earlier post. I don't want recognition, I only want to ear coments about the circuit from more experienced hams, I am computer engineer!! ;-). I was looking for a good, simple and easy design in the Internet but I not found it, It is the reason I make the design and program to drive the PLL. I don't know the designs of VK6BRO Richard Hosking, but i think they are complex. I will publish this work in the huff-puff group. P.D: My BITX with a FI of 32MHz and VCO of 53MHz is working, but it is very bad, with BF495 transistor, i only output 1 Wat, and the PLL show some inestability. The VCO, BFO and filter works at 32MHz. I think the bilateral amplifier don't work at 32MHz. I miss something? 73s Manuel EB7HPM/EC7ALV |
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Rahul Srivastava
Hi! Manuel,
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It is not that we missed your work in fact we looked at it with great interest. I was interested in a PLL design for VFO for long. My opinion by using a PIC we complicate things.
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Now a PIC and 145170 combo is as simple / complex as PIC and AD9851.?Since we can get the DDS chips as free samples hence a DDS design appears more practical.
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This does not means that a PLL is no viable , I have been working on a dicreet design using 74192 chips with 10Khz ref pulling. The same comcept can be implemented upon a MC145151 as done in Multipig design.
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You are right about high ft IF limitations . As per simulations done by our Prof Rob there appers roll off of frequency due to highly negative feedback nature of amp designs. I am evaluvating results of? high Ft BJT devices. Maybe one back this design would evolve into a basic building block towards a multibander.
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73
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Rahul VU3WJM
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eb7hpm wrote:
How much free photo storage do you get? Store your holiday snaps for FREE with Yahoo! Photos. |
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Try to change transistors.2sc2571a or bfr96 bfr91 or any other with
ft of 5 ghz. There is big chance that capacitor values in crystal filter are not appropriate. Even behavior of the crystals in lattice filter on such high if should be considered. It is not that we missed your work in fact we looked at it withgreat interest. I was interested in a PLL design for VFO for long. My opinion by using a PIC we complicate things. AD9851. Since we can get the DDS chips as free samples hence a DDS design appears more practical. on a dicreet design using 74192 chips with 10Khz ref pulling. The same comcept can be implemented upon a MC145151 as done in Multipig design. done by our Prof Rob there appers roll off of frequency due to highly negative feedback nature of amp designs. I am evaluvating results of high Ft BJT devices. Maybe one back this design would evolve into a basic building block towards a multibander. they are complex. I will publish this work in the huff-puff group.it is very bad, with BF495 transistor, i only output 1 Wat, and thePLL show some inestability. The VCO, BFO and filter works at 32MHz. Isomething? Service. for FREE with Yahoo! Photos. Get Yahoo! Photos |
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Thanks for your helpful coments, Rahul.
You are right in the DDS issue, the PLL chip could be dificult to find. I don't like DDS for the noisy output, but I am not tested this and I am not make a DDS prototipe yet. Using a PIC could be complicate in software programing and chip programing, but then it is easy. Using a PIC offers more posibilities to the transceiver and ease operation in my opinion. I don't want to change the easy bilateral BITX configuration, I try some high Ft transistor an then possibly I keep the low FI. I change it to 12MHz for a problem with 10MHz in my BITX 15meter band. The second armonic in 20MHz was at the antena with the useful signal at 21.185MHz, then ROE adjust was impossible !!! Manuel EB7HPM/EC7ALV --- In BITX20@..., Rahul Srivastava <vu3wjm@y...> wrote: Hi! Manuel,great interest. I was interested in a PLL design for VFO for long. My opinion by using a PIC we complicate things. AD9851. Since we can get the DDS chips as free samples hence a DDS design appears more practical. on a dicreet design using 74192 chips with 10Khz ref pulling. The same comcept can be implemented upon a MC145151 as done in Multipig design. done by our Prof Rob there appers roll off of frequency due to highly negative feedback nature of amp designs. I am evaluvating results of high Ft BJT devices. Maybe one back this design would evolve into a basic building block towards a multibander. they are complex. I will publish this work in the huff-puff group.it is very bad, with BF495 transistor, i only output 1 Wat, and thePLL show some inestability. The VCO, BFO and filter works at 32MHz. Isomething? Service. for FREE with Yahoo! Photos. Get Yahoo! Photos |
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Ashhar Farhan
while PLL chips are difficult to find, the 16F84 or the 16F628 are plentiful. why can't we program the PIC to behave as a PLL on it's own?
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the PIC timer can be used to accurately measure the oscillator frequency (as normal PIC based frequency counters do) instead of displaying the frequency on a display, it can (in addition) also pump a capacitor that in turn is used to bias a varactor across the VFO. if chris and his merry band can do a single chip HnP, there is no need to assume that they can't turn out a single mirochip PLL too. the rumors about having to program the pics are exaggerated. probably an audio amplifier is more of a challenge than wiring togther a PIC programmer. i build one whenever i need to program a pic, it is usually easier to solder a couple of diodes than search out the old programmer again. - farhan On Sat, 9 Jul 2005, eb7hpm wrote:
Thanks for your helpful coments, Rahul. |
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Jim Strohm
On Jul 10, 2005, at 7:04 AM, Ashhar Farhan wrote:
while PLL chips are difficult to find, the 16F84 or the 16F628 areGiven how cheap a PIC is, I think it's just a matter of time before we stop using standard TTL/CMOS logic, and start programming PICs as replacements. They won't be pin-for-pin replacements, but they'll be easier to locate than some of the more esoteric logic chips. A PIC PLL sounds like a fabulous project. Jim N6OTQ |
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Sam Caldwell
the PIC timer can be used to accurately measure the oscillator frequencyAs a latecomer to pics and picaxes I have managed to stumble through some of the basics, but causing a number of LEDs to come on and off is hardly exciting. I have assembled a kitset frequency counter without having a clue as to how it worked, because the chip was preprogrammed. Can anyone point me towards an internet source where I might get an explanation of how a pic ( or picaxe ) might be used for this purpose, i.e what the program has to do, and why. Regards, Sam C. ZL1SAM |
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Ashhar Farhan
this is going off-topic, so i hope to make this a last post on PICs.
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the frequency counting code for PICs is pretty nifty and it does the timing based on execution times of its own code and reads off the number of cycles-ticks tha accumulate in the timer register. you can go through david tait's excellent archives on the net to get you started. i have used microchip's own IDE to simulate, debug and assemble the pic programs (written in assembly ofcourse). the frequency counters based on PIC invariably use the code given in an application note that you can download from their website on www.microchip.com. - farhan On Mon, 11 Jul 2005, Sam Caldwell wrote:
the PIC timer can be used to accurately measure the oscillator frequencyAs a latecomer to pics and picaxes I have managed to stumble through |
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Arv Evans
How about a PIC based Huff & Puff stabilized VFO that could also display the
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frequency? Arv K7HKL _._ On Sunday 10 July 2005 09:18 am, Jim Strohm wrote:
On Jul 10, 2005, at 7:04 AM, Ashhar Farhan wrote: |
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ajparent1
--- In BITX20@..., Jim Strohm <jstrohm@e...> wrote:
Three things: PIC is a sequential device, there are whole classes of logic solutions that are not easily done with a sequential device. Using the PIC as a PLL, it could be done but even the fastest parts are far too slow to be succiciently precise. With PLLs a lack of precision can be causes noise in the signal. The core of most PLLs is the phase detector which is usually a very fast sequential logic element to in real time compare the phse of two signals. Hard to do well enough with a PIC. Using a PIC for HnP and display, this is very do able. Allison KB1GMX |
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Arv Evans
Allison, & others...
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Since the time constant in an H&P (Huff and Puff) stabilizer is usually much longer than that of a traditional PLL, a PIC-based H&P design might be quite easy to implement. I wonder about the posibility of using the PIC H&P as a slow tuning PLL-like unit where the PIC would control frequency over the full tuning range. With such a design the operator might enter a frequency via the keypad and the PIC would take over and slowly tune the VFO to the requested frequency. "Slow" here being a relative term that could be quite fast if a lookup table were employed for gross settings of the DC offset for particular frequencies. One big advantage of using a PIC for frequency display is that VFO offsets are easy to accomodate (i.e. the display can show the operating frequency, although the actual VFO may be on some other frequency as in superheterodyne designs). This also works for LSB-CW-USB offsets of the BFO frequency. This use of a PIC (or any other micro-controller) as a H&P control element is something that might be best discussed in the context of the Huff & Puff VFO forum at <>. Arv K7HKL _._ On Tuesday 19 July 2005 06:51 am, ajparent1 wrote:
--- In BITX20@..., Jim Strohm <jstrohm@e...> wrote: |
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