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Re: VCO/PLL questions
Responding to the final part first. When you say it "looks quite clean" on your analyser, what IF bandwidthg was that lookign in? As to what it sounds like - it is quite easy to get a synthesizer that ;sounds OK; on SSB type bandwidths these days. Any synth with a loop bandwidth greater than 10kHz or so and a decent modern low noise phase detector will sound fine. Any of the chips made this century (which just about covers the one you're using) and apackaged VCO will give decent enough results.
IF, and its a big if, your poor QPSK demodulation is down to poor phase noise then this will be the total phase noise in your QPSK bandwidth of 2MHz that influences things. So its a bit odd that lower symbol rates should suffer more than the higher one. Could you perhaps have a spurious line or lines present - perhaps from a noisy reference signal ? Althogh, I guess you would have seen this is present.
Having said that, a ROS VCO and LMX2325 is a simple reliable enough combination although the 2325 is a bit old now and there are better devices out there costing pennies. But what loop bandwidth did you choose? You requirement is rather different to narrowband working where a couple of tens of kHz is adequate. It may be worth widening loop bandwidth to attempt to reduce far out phase noise a bit more, at the expense of close in. Keep the reference frequency has high as possible so the N divider has a low value, this lowers loop gain so added noise has less effect. For an LO with a nice round number of MHz, a Fref of 1MHz or 2MHz is quite reasonable. That chip allows a maximum of 10MHz at the phase detector so you have plenty of scope
In conclusion, unless you've really got the loop filter components badly wrong, its unlikely to be PLL phase noise that is compromising your QPSK demod. And if PN were that bad, that would show up on a spectrum analyser with a mediun to narrow resolution BW. If it looks clean enough on the analyser in the QPSK bandwidth, then it almost certainly is, and teh poor demod is down to other reasons.
One piece of test equipment that is really invaluable for setting up synthesizers is a direct sampling SDR like the SDR-IQ and a good phase noise downconverter (an old fashioned crystal/multiplier chain into a DBM is perfect. Harmonic mixing in the mixer allows extra coverage). That combination will let yop look at phase noise from really close in and out to a few MHz. In teh absence of that, a spectrum analyser with RBW that goes down to 1kHz is near enough for practical purpses.
Andy G4JNT
On 28 December 2012 23:20, Rob, M0DTS <rob@...> wrote:
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Re: Réf. : Re: G3WDG e mail pse?
John Lambo
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Re: Minicircuits PHA-1+
adam <adam9a4qv@...>
And the new lucky owner of ADF4350 PLL is.....
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:-) Just jocking.. Well, I still have the PHA-1+ on the board, so will measure the performance to give you some idea, it was not bad at 1.3 and 2.3 but not even close to AH-102A. By the way AH-102A is working good also on 3.4Ghz producing some 250mW... Will let you know the results on 5.7Ghz soon. Adam http://croatia-microwave.blogspot.com/
--- In ukmicrowaves@yahoogroups.com, Richard <richard@...> wrote:
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VCO/PLL questions
Rob, M0DTS
I'm working on a few mods on some 9cm units for some Digital ATV activity on 3.4GHz and have a some questions for those who know much more about PLL/VCO's etc..
So... I have a board with Rx/Tx capability on 3.4GHz, common VCO was originally a ROS-2796 VCO and PLL is LMX2325. I've swapped out the VCO for a UMZ-2224 to give the ability for 23cm IF as this allows VCO to be low as about 2.12GHz. Currently programmed for 2162MHz the VCO is running using a PIC to control. I'm feeding in a QPSK signal on the low end of 23cm band with RF out at 3.4GHz then trying to receive it with a good receive system. (C-Band LNB which works fine on satellite transponders as low as 2Ms) Reception is intermittent at best but gets better wither higher QPSK symbol rates... >4Ms/s Now the main question... is it too much phase variation on the VCO that is causing poor demodulation of the QPSK signal or something else? drive level to the whole tx converter appears to have no effect and is quite linear. I have not listened to the 'tone' of the VCO but looks 'quite' clean on my analyser... what would phase variation sound like.. rough tone? I have a 13cm transverter LO so could mix with that to 23cm NB rx, will sort that out soon to listen... Varying the R/N counters in the PLL appears to have some effect but way off what is needed still I suspect. I'm a real newbie to programming pll's and configuring the filter etc so would appreciate some ideas on how to proceed to confirm what I think is the problem and then a way to resolve it hopefully! Rob M0DTS
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Re: Minicircuits PHA-1+
Richard <richard@...>
On 28/12/12 22:27, adam wrote:
Thanks for the info Adam. How poor did you find the performance on 6 cms , luckily I only need to go to 4.4 GHz HNY-- Best wishes / 73 Richard Bown e-mail: richard@... Mail now hosted by SimplyMailSolutions Please avoid using old e-mail address of richard.bown@... nil carborundum a illegitemis ################################################################################## Ham Call G8JVM . OS Fedora FC17 x86_64 on a Dell Insiron N5030 laptop Maidenhead QRA: IO82SP38, LAT. 52 39.720' N LONG. 2 28.171 W ( degs+mins ) QRV VHF 6mtrs 200W, 4 mtrs 150W, 2mtrs 350W, 70cms 200W Microwave 23 cms 140W, 13 cms 100W, 6 cms 0W & 3cms 5W ##################################################################################
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Re: Minicircuits PHA-1+
adam <adam9a4qv@...>
I had the same idea of using this device on 6cm, but I was not happy with the performance on 6cm...
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I get mine from DEMI... Adam
--- In ukmicrowaves@yahoogroups.com, Richard <richard@...> wrote:
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Re: Réf. : Re: G3WDG e mail pse?
Anthony Horsfall <x600@...>
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Réf. : Re: G3WDG e mail pse?
F6DRO
Hi Arie ,
I see no text in ur mail. Still no adress for Charlie rxed 73 Dom
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Activity Reports for Scatterpoint - Reminder
Robert Price <g8dtf@...>
Hi All I am just trying to put together the Activity report for Scatterpoint. Its a bit light at the moment. Reports on the 23cm UKAC or other activity would be welcome. Please send your reports to Scatterpoint@...
73 Bob G8DTF
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Re: G3WDG e mail pse?
Arie Dogterom <pa0ez@...>
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G3WDG e mail pse?
F6DRO
Hello all ,
I am looking for Charlie's E mail address 73 and HNY Dom/F6DRO
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Minicircuits PHA-1+
Richard <richard@...>
Hi
Has anyone already ordered any MCL PHA-1+ devices they could part with a couple, or anyone interested in a part/shared order MOQ is 20 @£1.62 or it drops down more at 50+. Nice devices usable on 6 cms , 100mW MMIC in a SOT89 package. I've got one earmarked for the dead modulator amp in a HP sweeper plugin TIA -- Best wishes / 73 Richard Bown e-mail: richard@g8jvm.com Mail now hosted by SimplyMailSolutions Please avoid using old e-mail address of richard.bown@blueyonder.co.uk nil carborundum a illegitemis ################################################################################## Ham Call G8JVM . OS Fedora FC17 x86_64 on a Dell Insiron N5030 laptop Maidenhead QRA: IO82SP38, LAT. 52 39.720' N LONG. 2 28.171 W ( degs+mins ) QRV VHF 6mtrs 200W, 4 mtrs 150W, 2mtrs 350W, 70cms 200W Microwave 23 cms 140W, 13 cms 100W, 6 cms 0W & 3cms 5W ##################################################################################
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Christmas Contacts
Graham - G4FSG
Happy Christmas to everyone! As has become tradition, Sam, G4DDK, and I
made contacts on as many bands as possible this morning. This year we were aided by Simon, G3LQR. Sam and I had full two way contacts on 6m, 4m, 2m, 70cm, 23cm and 13cm. Sam had a 'one-way' to Simon on 9cm and I had a 'one-way' on both 6cm and 3cm to Simon. Between us we learned a number of lessons! The problems were not with RF but DC Tx/Rx switching. All three of us had problems resulting from reconfigurations that have occured over the last few weeks/months. Simon could receive but not transmit on any frequency above 70cm. Sam had problems with 13cm and I had problems with 23cm. I also realised afterwards that in making contact with Sam on 6 bands, I had used 5 different driver rigs! Despite the problems we were pleased that the East Coast of Suffolk had activity on all 9 bands from 50MHz to 10GHz. We left it to others to operate on 30MHz and below. Next year we should aim to add another band.........472kHz? Back to the Malt Whisky and mince pies! 73 Graham G4FSG
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432 and Above EME Newsletter for Jan 2013
rein0zn@...
Hello All,
The 432 MHz and Above EME newsletter for January. 2013 by K2UYH is at: http://www.nitehawk.com/rasmit/em70cm.html - Contest Results. - Lunar Calendar for 2013. - VK7MO's 10 GHz portable Operations. - More Enjoy. Merry Christmas and a vy good New Year to All. 73 Rein W6SZ
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Re: PGA Amplifiers
Eddie G0EHV
--- In ukmicrowaves@yahoogroups.com, SAM JEWELL <jewell@...> wrote:
Sam, I'm certainly interested in 2, maybe 3 kits. What is the performance at 13 cms I wonder? The spf5043 has 10.9 dB gain and 1.2 dB noise figure. Is it bettered or broadly similar? Also, when will boards with space for filters and connectors be available ? Thanks and Happy Christmas, Eddie G0EHV
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PGA Amplifiers
SAM JEWELL
Santa has arrived early today! A few members on the reflector asked me to let them know when I had received the PGA AMP parts ( Radcom and DUBUS). This seemed the easiest way to reach them. I now have PCBs and devices for the PGA103+ low noise, high dynamic range amplifiers, courtesy of G8EMY and special delivery by Santa in a decidedly non-sleigh white van earlier today. I have uploaded details and a PDF on my web page for anyone who is interested. www.g4ddk.com Merry Christmas and Happy New Year to everyone! 73 de Sam
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Re: OT:Re G3AAF
Grant Hodgson <grant@...>
Richard
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Don't know about ebay, but their trading company is RFDesignUK (there are at least two of them - Kevin and Martyn I think). www.rfdesignuk.com regards Grant G8UBN
On 22/12/2012 23:25, Richard wrote:
Hi
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OT:Re G3AAF
Richard <richard@...>
Hi
Does anyone know what Kevin, G3AAF, trades under on ebay,his ebay alias, or if he has an ebay shop ? Thanks -- Best wishes / 73 Richard Bown e-mail: richard@g8jvm.com Mail now hosted by SimplyMailSolutions Please avoid using old e-mail address of richard.bown@blueyonder.co.uk nil carborundum a illegitemis ################################################################################## Ham Call G8JVM . OS Fedora FC17 x86_64 on a Dell Insiron N5030 laptop Maidenhead QRA: IO82SP38, LAT. 52 39.720' N LONG. 2 28.171 W ( degs+mins ) QRV VHF 6mtrs 200W, 4 mtrs 150W, 2mtrs 350W, 70cms 200W Microwave 23 cms 140W, 13 cms 100W, 6 cms 0W & 3cms 5W ##################################################################################
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Re: JT4G RS test this morning anyone? I'm on 10368.100 and KST
Well , they stand more chance of decoding you, John. Iscat-B doesn't seem to stand up too well with RS. However strong the signal might be, the fast scatter causes corruptions.
API's decodes of me show somwe interesting variations on callsign and locator
'jnt
On 22 December 2012 11:38, G4BAO <john@...> wrote:
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New reverse beacon for 2.3 and 10 GHz in EA
Maximo Coltro <ea7fgj@...>
Good morning to all! I want to tell that we have two "reverse beacons" in Alicante. One for 10 GHz band, with one LNB with PLL, 60 cm diam offset TVSat parabole and one FunCubeDongle, to Ibiza, we Rx the beacon in 10368.910 MHz, ED6YAE. The other "reverse beacon" was made with a WiFi downconverter with PLL, antenna Patch with Dishes, like a yagui but with dishes, and one FunCubeDongle, in this case we point to Sirius sats 2320.290 MHz. http://maxiplaya.dyndns.org:8901/ Both waterfall in the same screen! Very good job!!! Many thanks to Max, EA5CV and Luis, EA5DOM. Saludos cordiales. Máximo. EA7FGJ. IM67XI.
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