Help please to receive HF

jdow
Posts: 643
Joined: Mon Aug 10, 2020 8:17 pm

Re: Help please to receive HF

#11

Unread post by jdow »

First you must attach an antenna to the right place in the dongle. I believe this requires disassembly of the dongle and attachment of a coax cable for the more sensitive mode. That creates a direct I only or Q only sampling situation. The other mode detunes the front end and relies on a leakage path created by the detuning. Sensitivity is low. This is enabled in the rtlsdr configuration property pages.

May I suggest a visit to the https://www.rtl-sdr.com/ website and getting the official hookup instructions. I don't have an rtlsdr dongle hooked up at the moment to give you step by step instructions regarding getting to the property pages and settings on them. Go to the same web site where you got the SDR-Radio.com programs and studying the drop down menus at the top. The n-z menu might surprise you.

I cannot come close to describing my negative attitude about doing this enough. It is as close to a waste of effort as you can get. (For planning on SDR transmitting in the future you might look into the Hermes Lite boards that go on group sale from time to time. It is a night and day difference on receiving on it vs rtlsdr dongles. You also won't one active in your house because they radiate like *swearwords* on multiples of 28.8 MHz, such as 144.0 MHz.)

{^_^}

Max
Posts: 564
Joined: Thu Aug 13, 2020 9:47 am

Re: Help please to receive HF

#12

Unread post by Max »

jdow wrote:
Tue Jan 17, 2023 9:25 am
First you must attach an antenna to the right place in the dongle. I believe this requires disassembly of the dongle and attachment of a coax cable for the more sensitive mode.
{^_^}
Joanne, I don't think he needs to do this as it is the RTL-SDR V3 from the RTL-SDR.com shop. Well, I've got one and it already works on HF via SDRC without any mods....

HOWEVER...... Jaume...... I 100% agree with Kriss's advice. If it's HF you are interested in, do yourself a massive favour and pick up an HF+ Discovery. For anything more than the most casual use the RTL-SDR will just bring huge disappointment at HF. The Airspy HF+ is hands-down the most cost effective option for an HF SDR that works very well with SDRC.

https://airspy.com/airspy-hf-discovery/

I agree with Kris also to maybe steer clear of SDR Play RSP receivers for HF. They do overload too easily at LF/MF/HF and also they have a front end that is probably more susceptible to static damage than most if you are not able to be local and disconnect the antenna during lightning storms. I also agree with Kriss that the many adjustments needed are also a nightmare and rarely very satisfactory. Bit of a mess.

I don't know if the Airspy HF+ is as bad as the RSP regarding static damage? Kriss will know as he has both receivers and plenty of regular storms! If you must get an SDR Play RSP, then go for the RSPdx which has additional front end filtering in an attempt to solve the overload issues.

Good luck!

Max

jdow
Posts: 643
Joined: Mon Aug 10, 2020 8:17 pm

Re: Help please to receive HF

#13

Unread post by jdow »

I was not sure. The rtlsdr dongle I tested was rather an old one. The new, when looking at its limitations, did not excite me. It's 8 bit sampling gives too limited a dynamic range for HF as I see it. Anyway, that means a visit to Simon's main SDR site should yield suitable instructions and setup from the SDRC stand point.

For what it is worth I have 6 various VHF/UHF AirSpy devices (4 mini, 1 R2, and 1 original) that are my go to tools for VHF/UHF SDR projects. I have an AirSpy HF+ and an AirSpy HF+ Discovery that are both very nice for HF. (That's a hell of a big vote for Youssef's tools. He does pretty darn good work as I see it.) But, my go to for HF is, at the moment, either an RX888 or RX888 MKII. (Yeah, I am crazy.... I like the extreme bandwidth.)

{^_^}

G4ZFQ
Posts: 48
Joined: Wed Aug 19, 2020 10:26 am
Location: Cowes Isle of Wight

Re: Help please to receive HF

#14

Unread post by G4ZFQ »

While the genuine RTL dongle v3 is an upgrade on the originals introduced more than 10 years ago I rather feel the HF direct sampling is a poor introduction to HF. Especially with HF conditions as they are now spurious responses will be a problem. A large antenna and suitable filters may help.
They are better if used with an HF upconverter. I have some I have added a TCXO and converter, they perform adequately for a cheap homebuilt SDR. Upconverters are available but the final cost is not that far short of the ultimate.
If you are not up to home brewing then as others say, save up for an airspy Discovery then you have first class HF reception.
Alan

Max
Posts: 564
Joined: Thu Aug 13, 2020 9:47 am

Re: Help please to receive HF

#15

Unread post by Max »

jdow wrote:
Wed Jan 18, 2023 8:22 am
But, my go to for HF is, at the moment, either an RX888 or RX888 MKII. (Yeah, I am crazy.... I like the extreme bandwidth.)
{^_^}
Yes, I thought about RX888 but I think I am right in saying (?) maybe not the most straightforward to install for some? HF+ with SDRC is "plug and play".

But yes, RX888 is about same $ as HF+ and as someone who does not mind messing about with software etc. for ultimate flexibility it would be my personal choice for sure, and the VHF/UHF gets thrown in for free!

Then again, for simplicity, OP could have two radios at remote location. HF+ for HF and RTL-SDR for VHF/UHF. Trouble is as ever there will always be different opinions and solutions and as we know, tastes differ!

Max

Cabot1
Posts: 5
Joined: Fri Dec 23, 2022 11:04 am

Re: Help please to receive HF

#16

Unread post by Cabot1 »

Many thanks' to all.
Thank you for your answers that I am reading and looking at more documentation.
I think I'll buy another model.
Jaume Cabot

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