Posts by DL1GNM

Got those maximum LNBs last year for 5EUR. Just for the lens. It's a non PLL LNB.

Update!

Now I know the type of my old dish and some technical data:

Hirschmann - CSA 1212 G

Polarmount - CPM 1200 B

Feedmount - CDB 1200 G

Diameter d = 1,20m

f = 11.325 GHz

noise temperature @ 30° el. = 30 K

G/T (with 1.5dB NF of LNB)

gain = 40.6 dBi

beamwitdh (-3 dB) <= 1.5°

weight = 29.8 kg

wind load = 1.3 kN (@800 N/m^2, c =1.2)

Old Version V0.9Beta8 stuttering too... what happened?

Tried these unmodified LNBs without any improvement:

Megasat Diavolo Twin

Octagon Green HQ OTLG

Opticum Twin LNB LTP-04H

I can confirm this issue as well. It's only the beacon... and VLC versions work.

This is with the same dish as Goonhilly uses (~1.2m), lower beacon is blue 40dB - 6dB of noise floor (red) = ca, 34dB difference:

I know that I could improve ca. 1 dB of sensitivity from my WB measurements. Investigations to be done soon.

I'll try different LNBs soon. May be it will bring me some improvements.

Could be that the GPSDO (27MHz for the HD-BP2) degrades the signal quality somehow.

G0MJW: your dish size is > 1.2m I guess Mike?

Seems to be that I've some space for improvements...

A71A bcn: MER 10.7dB (8.9dB before change of the beacon)

1.2m offset dish, see here DL1GNM going to be QRV soon

Can anybody tell me the level of an external LO that I should apply (25MHz) to my triplexer?

Thank you.

MegaSat Twin LNB Diavolo; D66LOW GAIN V02B, 20150804

Uses 2x ZXNB 4202 (?),3x T1014, 1x 25 MHz X-Tal, 1x UTC SGA L8400G

OCTAGON Twin Green HQ, Model: OTLG GreenHQ, no Serial No.

T1015, SPT SP4202HN, 25 MHz X-Tal,

I've ordered two LT04H last year. Opened one and it uses a RT320M, 25 MHz X-Tal. Pictures enclosed. SN: 18-02-0 ...

Thank you so far. It's interesting, what is available. The taiyo yuden filter for example. Currently this is not available (mouser, digikey).

Small, affordable and a quite good attenuation.

Meanwhile we discussed the AMSAT up converter in combination with a 28-432 MHz transverter.

But keep on posting interesting solutions.

73 Mike

We know all that IF=28 MHz isn't a good choice. DX-Patrol gives the option but writes a filter is needed then (or you should...).

52 MHz (50...54) will be a little bit better.

I use 432MHz, but I asked for someone else who has no 2m or 70cm transmitter.

Achim, I know that kind of filter. May be from UHF Unterlage (DJ9HO et al...). But if you don't have the tools in your own workshop at home...

Thanks so far.

Thanks for moving my question to this thread that I did not find...

The Opticum is an idea, the horn has to be removed b a saw to use a 20/22mm fitting to bring it to the POTY.

It's for a friend that I cannot visit for known reason. So I give him an idea what to order that will work.

My station is fine.

Because he has a vy good HF rig I asked for a "special" bandpass as well (28MHz IF is not a good idea). But this is an other topic.

Opticum LTP04H would work by SDR-Console's beacon tracking I guess? Then this would be a good starting point.

Dish, POTY+LNB.

Transmit will be done in a second step.

73 Mike

LNB change faster than you can buy them. Mine works, but I'm frequently asked by newcomers for QO-100,"Which one I should get?" Good working models like the nice and small VENTON EXL-S or the "old" and famous Octagons are not available any more.

So, I'm asking.

What about a listing in this topic like this (but not filled with discontinued ones like my example)?

Type: VENTON EXL-S

Where to get: https://rd-digital.de/Venton-E…40mm-Feed-Single-LNB-01dB

Date of Order: 2019-07-28

Comments: single LNB, works UFB, no wobbling, easy to adopt to POTY. (This is a discontinued one. Sadly.)

73 Mike

Any ideas for an band pass filter, that is usable, if LO=2372MHz and IF=28MHz? Should be steep.

Regards, Mike

Thanks Peter! Works fine and the markers in SDR-Console were quickly adjusted to the new band plan.

The upper beacon has still the same level and my signal varies about 1dB over the transponder and has max. lower beacon level.

Regards Mike

Quote from DL9SEC

Also hier mein POTY mit ABS-Haube fertig silikoniert und montiert...

Ich denke, die Dämpfung von ABS bei 2,4 GHz ist im Rahmen und nicht all zu hoch, das 10 GHz Signal wird ja so nicht beeinträchtigt. Das Silikon ist hinter dem Hohlleiterausgang und der wird mit der (Venton) Linse abgeschlossen. Bei 10 GHz wäre ich mit ABS vorsichtiger, was aber hier keine Rolle spielt. Alternativ (ohne 3D Druck oder Fräsarbeiten) ist dann Heiners Lösung. Oder meine Vollumhausung.

Gut gemacht.

73 Mike

Quote from G0MJW

Please compare with rocket and post-results

@Mike:

POTY with POTY lens but without radom: MER 6.9dB D4

POTY with Venton Rocket Lens, but without radom: MER 8.8-9.0dB D6

POTY with Venton Rocket Lens, radom old position: MER 7.7dB D5

POTY with Venton Rocket Lens, radom new position: MER 8.7-8.9 dB D5/6

DATV-Beacon, empty WB Transponder - Habe die DATV Bake benutzt zum Vergleichen.

Result (Ergebnis): +2dB besser zu originaler Linse von Hans, PE1CKK, aber inkl. Radom. F/D ca. 0.68, Offset-Spiegel 120x129cm

Details found here (Details hier): DL1GNM-Antenne-Feed-LNB

73 Mike