Antenna input socket

Useful information regarding antennas for SDR products.
sdrplay
Posts: 625
Joined: Wed Jan 07, 2015 7:58 am

Antenna input socket

Postby sdrplay » Wed Jan 07, 2015 11:31 am

I am disappointed to see that an F type connector has been used on the SDRPlay for the RF input.\nThat''s about as non-standard as you can get.\nWhy not a BNC or an SMA as most people would have expected?\n73s Tracey G5VU

sdrplay
Posts: 625
Joined: Wed Jan 07, 2015 7:58 am

Re: Antenna input socket

Postby sdrplay » Wed Jan 07, 2015 11:58 am

There is also some F quick connector that you can screw to your cable connector and then plug in the device!\n\nThis will solve the threads alignment issue. ;-)

sdrplay
Posts: 625
Joined: Wed Jan 07, 2015 7:58 am

Re: Antenna input socket

Postby sdrplay » Wed Jan 07, 2015 12:09 pm

BNC is specified for a maximum frequency of 1GHz. And if you test the properties, you know why. It is a very unstable connector.\nFor high quality products SMA should be used.\nRF propeties of F-type connectors are good. But it is not a real connector.

sdrplay
Posts: 625
Joined: Wed Jan 07, 2015 7:58 am

Re: Antenna input socket

Postby sdrplay » Wed Jan 07, 2015 12:09 pm

All measured data for the RSP (see http://www.sdrplay.com/docs/SDRplay_Tec ... n_r1p1.pdf ) is with the F-connector. The principle reason for the choice of the F-Connector was one of mechanical robustness. SMA connectors can have a nasty habit of working loose. That said, we have taken on-board the various comments regarding the merits or otherwise of different connectors and will review this choice again for future revisions of the product

sdrplay
Posts: 625
Joined: Wed Jan 07, 2015 7:58 am

Re: Antenna input socket

Postby sdrplay » Wed Jan 07, 2015 12:11 pm

I can''t see what the problem is with the F-connector. It is low-loss to beyond 2GHz and it is simple to fit the plugs to the cable. OK, it''s 75-ohm, but that isn''t of great importance in this application. My only reservation about it is that it can sometimes be very frustrating when trying to screw the plug in on the back panel of a piece of equipment and the threads won''t engage or get crossed!

sdrplay
Posts: 625
Joined: Wed Jan 07, 2015 7:58 am

Re: Antenna input socket

Postby sdrplay » Wed Jan 07, 2015 12:47 pm

Hi Tracey,\n I agree with you about the antenna input socket, it should have been a BNC or SMA and I was also disappointed that the SDRplay is in a plastic box, I have been using it as a spectrum analyzer and it picks up my test oscillator without it been connected to it, and at a fair distance away from the test oscillator, it looks like I will have to put the sdrplay in a shielded box. At least when I do I will be a

sdrplay
Posts: 625
Joined: Wed Jan 07, 2015 7:58 am

Re: Antenna input socket

Postby sdrplay » Wed Jan 07, 2015 12:51 pm

We at SDRplay are very aware that for sub 1 GHz the choice of connector is not ideal. We are looking at adapters such as these from RS in the UK http://uk.rs-online.com/web/p/rf-coaxia ... s/5465092/ and will report back later. Jon G4ABQ

sdrplay
Posts: 625
Joined: Wed Jan 07, 2015 7:58 am

Re: Antenna input socket

Postby sdrplay » Wed Jan 07, 2015 12:51 pm

Hi G0NQE - We didn''t get the end of your comment , meanwhile, regarding the box, this is tricky. We know there are developers who are planning to integrate the RSP into a larger piece of equipment they are making where additional shielding and mechanical design mods will be necessary, but for most stand-alone applications, ruggedness and reasonably light weight were the dominating considerations. This led to the current exterior design of the RSP. Jon G4ABQ

sdrplay
Posts: 625
Joined: Wed Jan 07, 2015 7:58 am

Re: Antenna input socket

Postby sdrplay » Wed Jan 07, 2015 12:53 pm

Hi Jon,\n Sorry the end of my comment was lost, i''m not sure what went wrong but i''ll put it down to age hi.\nI was going to say that at least if i build the SDRplay into a metal enclosure i can fit a bnc socket for the output.\nAs i''ve said my use for the SDRplay will be spectrum analisys, my first attempt worked but the signal from my test oscillator was picked up by the SDRplay unit, my step attenuator made no difference to the strength of the signal being received after about 40dB.\nWhen i have done my modifications ie. fitted the unit in a rf proof box i will get back to you with the results.\n\n73, Colin G0NQE

sdrplay
Posts: 625
Joined: Wed Jan 07, 2015 7:58 am

Re: Antenna input socket

Postby sdrplay » Wed Jan 07, 2015 12:53 pm

Hello Jon, yes the RS adapter would do fine, there are similar ones on eBay at £2.99 for a packet of 5 with \nfree postage. See eBay Item 330936469562. 73s Tracey G5VU


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