No, these modifications were already there before QO-100, especially for 10 GHz (10.368 MHz) usage as alternative for the famous DB6NT transverters.
B.t.w. Thomas, when will we hear you on the satellite?
No, these modifications were already there before QO-100, especially for 10 GHz (10.368 MHz) usage as alternative for the famous DB6NT transverters.
B.t.w. Thomas, when will we hear you on the satellite?
No, these modifications were already there before QO-100, especially for 10 GHz (10.368 MHz) usage as alternative for the famous DB6NT transverters.
B.t.w. Thomas, when will we hear you on the satellite?
This was a joke Dear Remco
I was on the satellite, but my signal is too faint, I'm waiting for my parcel with my EDUP booster.
Rgr, then I wait until the postman rings ; -)
He has surprisingly ringed today morning, I have the booster in my hands. Now I need time to install it.
CU on QO-100
Thomas, I have forecasting skills (although no-one believes me, you're not the only one who experiences the proof, others (here in this forum) experienced the same.
Hint: one of these others is from the UK)
; -)
This was a joke Dear Remco
I was on the satellite, but my signal is too faint, I'm waiting for my parcel with my EDUP booster.
I think I would hear you, if you came on.
Mike
Nice feedback!
Nice experiment !
But why such a big ferrite ?
You have to transform ony miliwatts.
There are nice ferrites which are not bigger than the original crystal.
So you do not have to make a gap in the case.
I used a simple 1-hole ferrite with 3.5 mm outer diameter.
(see pictures on #18 this thread)
73s
Armin DF1QE
from past expirience - try to set 200~400 OHms resistor in parallel with secondary, pins of oscillator in IC. Coupling may sets better with 1:1 transformer. Othercase possible to use in ready one from Token balun transformer TCB4F
In my experiment I used a 'ferrite pearl' (Ferritperle <-- German, or 'Ferrietkraal' <-- Dutch) of which I measured the AL and then wound it with windings so that XL of the windings was high enough. I only tested it with the Inverto 'Red Extend', not with other (non Inverto) LNB's.
I see. by the way, AL measured not in all ferrite beads. they have very high Mu parameter, about 2,000~5,000. Ready one transformer it's very cheap today. usually in ferrite beads measured impedance in some frequency range. this is very important parameter. not every company reproduce same tables. please see on the picture attachment in sample.
But why such a big ferrite ?
You have to transform ony miliwatts.
The power to be transferred is not the only consideration.
With method 1a, the entire operating current of the LNB flows through the primary winding.
This can lead to saturation of a too small core.
in the pictures mounted RF transformer from TOKO 617PT-1026 (1:1). Datasheet is attached.
Pads of XTAL go out with XTAL. now connected with wires. need 2 solders to remove XTAL.
And .. does it work ?
i will see it later. and your device is working?
Yes, it works .. but I default use another LNB , SR-320.
i'm try to operate, long story for this moment in what's way i'm making my test,but not working. may be it's phasing of trafos in port, may be clock 25 MHz has low RF level.
tomorrow i will try to set few photos of setup. i have few LNB's for compare, ugraded one not so running, but hope not die yet
Today i repeat setup, it's working! All stones is RF level of external clock. In this time i'm using N2PK stand alone with touch screen and internal program as source of 25 MHz.
In fact that i use QINTAR standart splitters of 75 Ohms, must to do some adapt 50=>75. Those models is old from 1991, different ranges, but all pass DC to one or all ports. Also coax cables is 75 OHms, only BNC is 50.
My source is 54 MHz~13,6 GHz loaded via horn 10~11 GHz have some moving piston inside to adjust exact range. Tuned and transmitted on 10,489 MHz.
See attached pictures. Also, LNB with POTY (no ext clk).
PA3FYM : Hi Remco !
Yesterday I modified an older Divavolo Twin LNB.
It was what I call in my reports the V3. (not found often)
I did that as help for another OM.
It has a complete different design compared to modern LNBs.
For each channel works a seperate PLL & Mixer chip, but with a common 25 MHz X-tal.
The chips are TFF1014HN from NXP.
In an NXP short form application catalog I found exact this design.
So I started my usual methode to find the in and out pins.
25 MHz injected to one pin and monitored the other pin if they come out.
And right the first test was fine.
For some reason, I don't know, may be it was the RF sense of my body , I twistet the pins and what wonder : The 25 MHz were also transfered, with the same quality and level.
Another wonder was, that one pin had a few volts DC-Level, the other not.
It was not possible to follow the PCB tracks, so I assume one pin is capacitive coupled.
So what type of Oscillator ist that ?
The answer is simple : It must be a push-pull oszillator.
https://www.google.com/search?q=gegentaktoszillator
This oscillators are fully symmetrical an were frequently used for high frequency x-tal oscillators.
Now it makes sense, why there is no specific in- and outpin.
They remind me to my old pirate radio transmitters I build 45 years ago 2xCV6 or ECC85
But the thing why I write this to you is : Now your whole thread about symmetrial feeding the LO makes sense.
If inside the chip, the design continues to be symmerical, it's sure that symmtrical feeding improves the singnal quality.
I tested both feedings asymetric and symetric, and the signals at the x-tal pin were extreme better with symetrical feeding with a transformer.
So again I must say thanks to you for this great idea !
But for all others : Keep in mind, the symetrical feeding is important for this type of oscillator only, othes work better asymetric.
I documented all with photos and will write a report about the modification as soon as find the time.
And BTW, I found a perfect FXC for a trafo : the inductivity found in an old GEDU2411 Antenna wall plug from Hirschmann.
With windings it has exact the size of the HC49 x-tal and it has a big inner hole to take enough windings with good isolation.
73s
Armin DF1QE