Re: Cheap 1 - 3000 MHz RF bridges

Alan Melia
 


Interesting, I don't think this design is anywhere near original! I remember an article in VHF Comms about 10 or more years ago I did build one then on prototyping pcb.
 
Alan
G3NYK

----- Original Message -----
Sent: Thursday, December 19, 2019 10:47 PM
Subject: Re: [UKMicrowaves] Cheap 1 - 3000 MHz RF bridges

Hi Andy, just checked the duff one and yes you and Alan are right it is the resistors. I had to use a handheld microscope to see it though as the soldering is such a mess and obscures PCB tracks. In answer to Kent, the genuine thing and the copy both have transverter-store printed on them. If you look at the guy's website he is clearly hacked off with the Chinese copies! 

Sent from my Huawei phone


-------- Original Message --------
Subject: Re: [UKMicrowaves] Cheap 1 - 3000 MHz RF bridges
From: Andy G4JNT
To: "UK Microwaves groups.io"
CC:

It's only resistors soldered incorrectly - well mine was.  Easily repaired



On Thu, 19 Dec 2019 at 21:01, G0FVI via Groups.Io <Andrew.gilfillan=ntlworld.com@groups.io> wrote:
The guy who originally produced them is in the Ukraine (www.transverters-store.com). Cheaper Chinese copies have cropped up on ebay and as you say many do not work. Got stung here, ended up buying the authentic device. The duff one is sat here, couldn't justify the time to fix it!

Sent from my Huawei phone


-------- Original Message --------
Subject: [UKMicrowaves] Cheap 1 - 3000 MHz RF bridges
From: Alan Beard
To: UKMicrowaves@groups.io
CC:

Hi all,
Thursday 19th the RF bridges arrived.

3x marked 0 1 - 3000 MHz   all three don't work !!!!

1x marked 0.1 - 3000MHz    Yeh it works !!!! p/n 140109

Examining the faulty boards, the track from the DUT port goes to a
100 ohm resistor to the Input port BUT not to the bridge OUT.
Similarly the REF port goes to a 100 ohm but not the other.

I assume they use two 100 ohm resistors in parallel to give 50 ohms.

I soldered a wire across the two resistors, both REF & DUT, on the ferrites
side.
All fixed. The faulty boards are marked 191922 on top and XR-104 on the rear.

Testing with the Simple Spectrum Analyser with Tracking Gen, work well
up to their stated 3000 MHz.

Alan VK2ZIW


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Alan Beard

OpenWebMail 2.53




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