Looking to get a DC Power Inserter for my radio telescope

[robin_astro]

20 hours ago, Carl Reade said:

I'm supplying the LNA with around 9 or 10V. I attach the Voltmeter to the OUT SMA port (only 0.24V...):

 You should be looking for DC on the ANT socket on the LNA (the input that connects to the antenna/LNB), Not the OUT socket which goes to the receiver.  You were lucky.  If there had been DC on the input (ANT), it might have damaged the HackRF.  There was no need to connect the HackRF when doing this test.

[Coto]

@robin_astro: I first tried it without the HackRF connected, but after not getting any "exciting" results, someone suggested I have it connected as it may provide some power? Anyway, I tried both ways as I showed in the pictures, but no luck, so I see myself getting a Bias Tee.

[robin_astro]

The HackRF One can supply some DC power for LNA etc   (You can see  the bias T circuit at the antenna input on page 3 of the schematic  https://github.com/mossmann/hackrf/blob/master/doc/hardware/hackrf-one-schematic.pdf   )   but according to the spec only 3.3V 50mA so not enough for this application.

[Tomatobro]

[Coto]

I’ve decided to get a bias tee from eBay. There are plenty of bias tees though. Could you recommend me one from eBay?

[Coto]

Will this work? - https://www.ebay.com/itm/RF-Divider-Biaser-Bias-Tee-10MHz-6GHz-for-HAM-radio-RTL-SDR-LNA-Amplifier-50VDC/113170701206?epid=21021845279&hash=item1a597fdb96:g:9Q0AAOSwvmxbWqtq

[Tomatobro]

Your LNB is rated at 80 ma and the board is rated at (up to) 500 ma so it should work.

I have ordered one for myself to evaluate

[Coto]

Alright, so I've ordered some things. Are all the connections right, or do I need to do anything else?

Labeling:

(1): LNB - https://stokostos.gr/tv-sat/lnb/signle/single-eco-slim-lnb-amiko-l108.html

(2): DAB9 F Type Male To SMA Female Jack - https://www.ebay.com/itm/DAB9-F-Type-Male-To-SMA-Female-Jack-RF-Coaxial-Coax-Adapter-Connector-Copper/173457691288?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

(3): SMA Male to SMA Male - https://www.ebay.com/itm/2Pcs-SMA-Male-to-SMA-Male-Plug-in-series-RF-Coaxial-Adapter-Connector-NN/273396469339?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

(4): Bias Tee - https://www.ebay.com/itm/RF-Divider-Biaser-Bias-Tee-10MHz-6GHz-for-HAM-radio-RTL-SDR-LNA-Amplifier-50VDC/113170701206?epid=21021845279&hash=item1a597fdb96:g:9Q0AAOSwvmxbWqtq

(5): SMA Male to SMA Female - https://www.ebay.com/itm/222700306760

[Carl Reade]

23 minutes ago, Coto said:

Alright, so I've ordered some things. Are all the connections right, or do I need to do anything else?

Labeling:

(1): LNB - https://stokostos.gr/tv-sat/lnb/signle/single-eco-slim-lnb-amiko-l108.html

(2): DAB9 F Type Male To SMA Female Jack - https://www.ebay.com/itm/DAB9-F-Type-Male-To-SMA-Female-Jack-RF-Coaxial-Coax-Adapter-Connector-Copper/173457691288?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

(3): SMA Male to SMA Male - https://www.ebay.com/itm/2Pcs-SMA-Male-to-SMA-Male-Plug-in-series-RF-Coaxial-Adapter-Connector-NN/273396469339?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

(4): Bias Tee - https://www.ebay.com/itm/RF-Divider-Biaser-Bias-Tee-10MHz-6GHz-for-HAM-radio-RTL-SDR-LNA-Amplifier-50VDC/113170701206?epid=21021845279&hash=item1a597fdb96:g:9Q0AAOSwvmxbWqtq

(5): SMA Male to SMA Female - https://www.ebay.com/itm/222700306760

Power supply to the bias tee?

[Coto]

@Carl Reade The bias tee is powered via GND and DC pins.

[robin_astro]

I'd probably put the bias T at the receiver end so you don't have to run the power cable to the antenna. (The point of the bias T)

[Coto]

48 minutes ago, robin_astro said:

I'd probably put the bias T at the receiver end so you don't have to run the power cable to the antenna. (The point of the bias T)

What do you mean? What power cable to the LNB?

[Carl Reade]

I meant what are you using to power to the lnb via the bias tee?

[robin_astro]

1 hour ago, Coto said:

What do you mean? What power cable to the LNB?

The power to the bias T.  The way you show it, you have the bias T at the LNB so you would have to run a separate power cable all the way to the dish. The point of a bias T is so you don't need to do that. You put the bias T at the receiver end and power it from there. The DC for the LNB is then fed up the signal coax.

[Coto]

So I should switch the position of (3) and (5) with each other?

 

@Carl Reade This adapter should do.