Search found 60 matches

by radiolistener
Sat Jan 18, 2020 4:06 am
Forum: Off-Topic
Topic: More fake units sold on Ebay
Replies: 34
Views: 36684

Re: More fake units sold on Ebay

I think they selling filters with terrible characteristics just because they use cheap component that they have instead of what is required. For example they can put a little different inductors just because they don't have inductor which is exactly needed. The same for capacitors. They can use indu...
by radiolistener
Thu Jan 16, 2020 3:06 pm
Forum: Off-Topic
Topic: More fake units sold on Ebay
Replies: 34
Views: 36684

Re: More fake units sold on Ebay

He meant the original filter RTL-SDR.COM, but component values are trade secret, of course. what is the secret? You can desolder components measure it and solder it back with no problem... :ugeek: I'm asking what component values are used just to put it into simulator and compare how aliexpress fak...
by radiolistener
Sat Dec 07, 2019 1:21 am
Forum: RTL-SDR Discussion
Topic: rtl-sdr dongle V3: Accessing the 28.8 MHz reference
Replies: 5
Views: 558

Re: rtl-sdr dongle V3: Accessing the 28.8 MHz reference

is it correct that extension pin CLK (or CIK) is 28.8 MHz oscillator output?

What is the meaning of the middle pin with no marking?
by radiolistener
Thu Dec 05, 2019 8:49 pm
Forum: RTL-SDR Discussion
Topic: Newbie : listening 3Khz to 148 Khz with upconverter ?
Replies: 8
Views: 998

Re: Newbie : listening 3Khz to 148 Khz with upconverter ?

The best SDR receiver for 0 Hz to 96 kHz is to use good quality sound-card "line-in" input. It will be much better quality than RTLSDR and other cheap SDR receivers (include upconverters) with price below $500. The only bad thing is that it's max receiving frequency is limited to about 96 kHz. With ...
by radiolistener
Tue Nov 26, 2019 5:37 pm
Forum: RTL-SDR Discussion
Topic: RTL-SDR as a rf analyzer?
Replies: 6
Views: 589

Re: RTL-SDR as a rf analyzer?

Yes, I came up with same specification, but it looks like 60dB 50w attenuator with sma connector is almost impossible to find, at least for a reasonable price...😕 https://www.aliexpress.com/item/32889026374.html https://www.aliexpress.com/item/32854048582.html https://www.aliexpress.com/item/328272...
by radiolistener
Mon Nov 25, 2019 3:54 pm
Forum: RTL-SDR Discussion
Topic: RTL-SDR as a rf analyzer?
Replies: 6
Views: 589

Re: RTL-SDR as a rf analyzer?

yes, you're needs 40 - 60 dB attenuator which can handle 20-30 W power. 40 dB should be safe for 5 W baofeng output, but signal may be still too strong and may overload the input. So, it's better to use 60 dB attenuator. Or you can combine 40 dB 20 W attenuator with a small 20 dB 2 W on the output o...
by radiolistener
Sat Nov 16, 2019 7:34 pm
Forum: Other SDR Devices
Topic: SDRplay announces the RSPdx
Replies: 8
Views: 1376

Re: SDRplay announces the RSPdx

Was that comparison done for HF? yes, this is done on HF. You can see screenshot above. On VHF, SDRPlay has significantly worse sensitivity than RTLSDRv3. And, if so, was the RTLSDRv3 in Direct Sampling mode or using an up-converter. I tested RTLSDRv3 in Direct Sampling mode. With no filters and no...
by radiolistener
Sat Nov 16, 2019 5:54 am
Forum: Off-Topic
Topic: whatever happened with mirics?
Replies: 4
Views: 541

Re: whatever happened with mirics?

they developed this chipset for tv dongles. But now tv is outdated. So, they transformed into SDRPlay and now selling tv chipsets as SDR receivers. The same as RTLSDR. But RTLSDR is more open hardware.
by radiolistener
Fri Nov 15, 2019 1:04 pm
Forum: RTL-SDR Discussion
Topic: distorted FM
Replies: 12
Views: 1122

Re: distorted FM

I recommend to use HDSDR. Because SDRuno and SDR# is too buggy.
by radiolistener
Fri Nov 15, 2019 9:17 am
Forum: Other SDR Devices
Topic: SDRplay announces the RSPdx
Replies: 8
Views: 1376

Re: SDRplay announces the RSPdx

> "Hi-Z" is a marketing thing which is usually used for bad design RF frontend. Why? If I understand it correctly, a Hi-Z input makes it easy to connect a long piece of wire and use that as an LW/MW antenna. There are two reasons: 1) high impedance leads to high thermal noise 2) impedance matching ...