Posts by PA3FYM

Quote from sv8qg

I found a Greek supplier of Octagon OTLG twin green, but it is a little different… it has only one crystal!!! Any ideas pls?

Remove crystal, make diplexer, insert 25 MHz reference. Ready!

OH1NHW Sorry to ask, why do you need a F-female to SMA-male adaptor?

When there is a coax cable ... mount an SMA (male) connector ... remember ... prevent 'adapters' ; -)

DD0KP Heiner, from the question of AMSAT (see initial posting in this thread) I thought it may be a nice idea to propose 'an emergency frequency'. To prevent a discussion on 'what' frequency it should be, I followed my statement with a proposal (.660) to align 'the noses'. I also stated it's fine with me when another frequency is favourable (as long as everyone knows that frequency).

So, it doesn't have to be .660. To summarize: I take the blame! ; -)

For every lens you need to adjust the focal point, because the phase centers are not the same.

Not: keeping the LNB in place and exchange the horns/lenses.

Ah , ok .. yes, but of course only when .660 is used in an emergency / calamity net. I reckon +/- 5 kHz would be sufficient.

Anyway, I'[m curious of the AMSAT-DL administrators support my/the proposal and if they're willing to mention it in the NB-tpx band plan. Bearing in mind -I repeat- every freq is ok, as long everyone knows the value.

Hmm... that are almost equal pictures. Can you make two pictures where there is key down of the CW beacon in both cases?

Try to set the sliders such that you've 40 dB 'dynamic range' in the pictures to prevent that the beacon clamps with the 80cm dish?

S57NML From what I understood / read, is that in most cases 'frequencies' are published and not a range of frequencies to avoid miscommunication and to assure everybody is listening to -and uses- the 'right' frequency. Same as e.g. 2182 kHz for the maritime sector, and not 2175 - 2191 kHz ; -)

Is it an idea to define 10489.660 as emergency frequency (also for future use) ?

That is, when there is no emergency .660 is a 'normal' frequency. When there is

an emergency .660 will be left alone by others (i.e. those not involved with

the pending emergency / calamity).

PS. Any frequency is fine with me, as long as everyone uses the same frequency ; -)

I mean the difference between your system noise and the received noise from the tpx.

E.g. pointing towards QO-100 you receive on 10488.000 MHz noise, and you receive noise on 10489.525 MHz.
How large is the difference ?

SV1BDS George, how much transponder noise do you have ?

DH1DA This ADF4351 is actually a complex and versatile device. For generating signals there are several routes to Rome.

From what I learned from the 'black science' of PLL's and (especially!) loop filters, is that a 'normal' INT PLL with lowest N as possible (and therefore highest PFD possible) delivers the cleanest signal. As a rule of thumb phase noise increases with N^2 (N-squared, or 20logN).

The FRAC mode isn't bad, but depending on the loop filter on these board. So .. for this given loop filter it needs a little experimenting with different settings (PFD and BW) to find the most optimal settings or you have to replace the loop filter components on the ADF PCB, which is a tedious job.

I built several applications with these PLL's (also passive, i.e. external oscillator and 'seperate' ADF PLL (like ADF4001, 4118, 4113, 4153 etc) and found that for every case I needed to fiddle and burnt hours struggling with ADISimPLL ;; -)

ON4CJQ We do not live in the Middle Ages anymore where a crook had to walk around with a plate quoting his offense and people could throw rotten tomatoes or eggs at that person. We live in 2019.... with (EU) policy concerning privacy.

From the datasheet it even has better P/N performance than the Bliley, but it's square wave and that often may be a nuisance because of harmonics 'flirting' around ; -)

Forgot the obligatory /2 division factor, so N = 2 x 787 = 1574.

See screenshot below:

David G0MRF try PFD of 2.5 MHz (or 500 kHz) as PFD and use INT-N.

You now do not have INT-N (N = 393.5)

2.5 MHz is GCD of 1967.5 and 10 MHz.

1967.5 / 2.5 = 787 (which is an integer ; -)

(you can also see it's not an INT because FRAC = not zero)

Use R-counter = 4 for PFD 2.5 MHz, or R-counter = 20 for 500 kHz PFD

(set 'channel spacing' accordingly, or omit the errors ; -)

(and I am personally a fan of 4/5 prescaler)

SV1BDS George! It seems you can read my mind! I ordered that one on Sep 23 to check it out : -)

DB2OS: No no .. no scaring at all, but nice pleasant talks with a few technical people (they are not all sales). I am aware that the commercial satellite world is very well regulated in itself, for obvious reasons. I also had some conversations for business purposes concerning Ka tpx's. I advised one of them to obtain his amateur license after which he shook hands : -)

I am also aware that the ∫ integral over the passband shall not exceed the nominal TWT power (OBPO included).

Perhaps in Es'hail-3 a separate TWT (and back up ; -) for the amateur service ? ; -)

CT2IRJ: The freenode chat is just very old fashioned IRC. BATC offers a webinterface on the NB-tpx WebSDR page, but you can also connect to the channel with a normal IRC-client (millions of people do that)

@G0MRF Dutch induced ! See this (first) posting (before the satellite was launched ; -)

Quote from HB9SKA

I think nobody expected these problems.

I did.

Having significant 'hands on' experience with SNG (satellite news gathering) in one of my former lives, and as former satellite co-ordinator of the Dutch government I spoke with several co-workers of Es'hailSat during IBC2018 and IBC2019 concerning 'how to deal with an 'undefined' user group'. They were flabbergasted ...

I fully agree with the posting of Achim DH2VA. The QO-100 tpx is a gift, something the satellite owner (Es'hailSat) offered us (i.e. the amateur community). In other words, Es'hail-2 is not founded 'for us'. We mooch. The satellite is intended to offer extra capacity for forthcoming global activities (...football) so, it's primary goal is NOT to serve the amateur community.

Bear that in mind and be humble (<-- also addressing pirates!)