More fake units sold on Ebay

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Airwind
Posts: 37
Joined: Wed May 23, 2018 8:27 pm

Re: More fake units sold on Ebay

Post by Airwind » Mon Dec 17, 2018 8:20 am

rtlsdrblog wrote:We've tried issuing takedowns on from Aliexpress and eBay, but as soon as you take one down, three more listings pop up in it's place.
Are there not any automated options available that scan for similar products and issue automatic takedown notices?
I hear the anti-piracy orgs use a lot of them for engine search results removal.

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m_a_x
Posts: 45
Joined: Sat Sep 13, 2014 10:13 pm

Re: More fake units sold on Ebay

Post by m_a_x » Mon Dec 17, 2018 8:39 am

Here is some manufacturer's solution:
https://www.eleafworld.com/info/batchcode.php

illllm
Posts: 22
Joined: Tue Apr 17, 2018 5:41 pm

Re: More fake units sold on Ebay

Post by illllm » Sun Dec 30, 2018 10:31 pm

As soon as you plug in those fake ones from China, they will steal all the information in your computer.

https://www.foxnews.com/tech/how-arrest ... ation-plot

drb
Posts: 2
Joined: Sun Jun 30, 2019 11:30 am

Re: More fake units sold on Ebay

Post by drb » Sun Jun 30, 2019 11:59 am

I bought from trademe.co.nz a device reputed to be an RTL-SDR v3 which differs in a number of respects from the pictures shown on the RTL-SDR.com Blog sales sites on Aliexpress and eBay.

The most obvious differences are that it has an electrolytic capacitor adjacent to the "TCXO"" and that the date on the bottom left corner of the board is "2018 4 18" rather than 2016. The sticker on the case shows NSY 2018 8

Is this a counterfeit or a revision?

rtlsdrblog
Site Admin
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Re: More fake units sold on Ebay

Post by rtlsdrblog » Mon Jul 01, 2019 4:29 am

drb wrote:
Sun Jun 30, 2019 11:59 am
I bought from trademe.co.nz a device reputed to be an RTL-SDR v3 which differs in a number of respects from the pictures shown on the RTL-SDR.com Blog sales sites on Aliexpress and eBay.

The most obvious differences are that it has an electrolytic capacitor adjacent to the "TCXO"" and that the date on the bottom left corner of the board is "2018 4 18" rather than 2016. The sticker on the case shows NSY 2018 8

Is this a counterfeit or a revision?
Newer revisions of the V3 board have added an electrolytic capacitor. 2018 4 18 refers to the production date of the PCB, and NSY 2018 8 refers to the date the product was finalised, QC checked and shipped out to retailers.

The images on the blog and sales channels are typically from the first 2016 batch which are the units that went to the photo shoot. Since then there's been a few minor changes, like the addition of the electrolytic cap.

The counterfeit ones that we've seen so far are very obviously counterfeit with yellow PCBs, square enclosures, and the PCB fits very loosely in the enclosure.

drb
Posts: 2
Joined: Sun Jun 30, 2019 11:30 am

Re: More fake units sold on Ebay

Post by drb » Mon Jul 01, 2019 4:59 am

OK, thanks. I guess it's genuine then. Reassuring to know that.

AcidJazz
Posts: 4
Joined: Sat Nov 25, 2017 3:29 pm

Re: More fake units sold on Ebay

Post by AcidJazz » Mon Jul 01, 2019 7:06 am

Many china FM reject filters has listing name "by RTL-SDR Blog" or uses grafiks of original filter,
for example https://www.ebay.com/itm/Broadcast-FM-B ... 2729543175
But really very bad fakes, doesn't supress 98-108 MHz
Image

radiolistener
Posts: 47
Joined: Thu Jan 25, 2018 10:48 pm

Re: More fake units sold on Ebay

Post by radiolistener » Thu Jul 04, 2019 3:14 am

AcidJazz wrote:
Mon Jul 01, 2019 7:06 am
Many china FM reject filters has listing name "by RTL-SDR Blog" or uses grafiks of original filter,
But really very bad fakes, doesn't supress 98-108 MHz
I bought one from aliexpress, store name: Piswords Store
Probably it has random values of inductors. For example L1,L2,L3 all have 47 nH.
But L2 should be a little higher for correct filter.
Also you can see L4 and L7 are different, but they should be identical for correct filter.

It have very high loss on 145 MHz.
And in overall it is useless, because it adds significant loss with not enough rejection of FM band.

Here is photo of it's PCB and bode plot:
Attachments
rjf-88-108-pcb.jpg
Reject filter 88-108 PCB
rjf-88-108-pcb.jpg (369.14 KiB) Viewed 1308 times
RX.png
Reject filter 88-108 Impedance
RX.png (27.24 KiB) Viewed 1309 times
RJF-180.png
Reject filter 88-108 Bode Plot
RJF-180.png (15.21 KiB) Viewed 1309 times
Last edited by radiolistener on Thu Jul 04, 2019 3:23 am, edited 2 times in total.

radiolistener
Posts: 47
Joined: Thu Jan 25, 2018 10:48 pm

Re: More fake units sold on Ebay

Post by radiolistener » Thu Jul 04, 2019 3:16 am

Here is how it works and VSWR measurement:
Attachments
rjf-sdr-compare.png
Reject filter 88-108 HDSDR performance
rjf-sdr-compare.png (756.13 KiB) Viewed 1308 times
S11.png
Reject filter 88-108 S11
S11.png (20.56 KiB) Viewed 1308 times
SWR-max15.png
Reject filter 88-108 VSWR
SWR-max15.png (16.41 KiB) Viewed 1308 times

radiolistener
Posts: 47
Joined: Thu Jan 25, 2018 10:48 pm

Re: More fake units sold on Ebay

Post by radiolistener » Thu Jul 04, 2019 3:41 am

I found this schematic and want to replace all elements in order to fix it.
Now, looking for smd inductors...
Schematic.png
Reject filter 88-108 MHz F1JKY
Schematic.png (54.1 KiB) Viewed 1300 times


Does anyone knows component values of original filter?

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