Hey,

This will take some getting used to...I have a hard enough time getting through my e-mails.  But, since this will be for homebrewers, it will be the first place I come to and I will do the e-mail later on!

Just finished building my Return Loss Bridge (RLB).  I've never used or owned one till now.  But I can see a lot of uses for it.  If you look in EMRFD, page 7.23, fig7.41 you will see the schematic for it.  I would post a pic but I had a terrible time trying to cut six exact square chunks of PCB.  I think I may have killed my bandsaw blade in the process.  Anyway, Mr. Dremel helped me smooth out the rough edges enough so I could close it up and keep it RF tight.

I had to use 51 Ohm resistors as I didn't have any 49.9 or 50 Ohm ones on-hand.  Just finished checking it out.  Took me a few minutes to get my head around the idea of a reference point needs to be established first before you can measure anything.  Once I got that step down, then I was checking the return loss on just about everything in the shack.  I had recently built up a small rf amp using a 2N5109 and thought that the input and output impedances were setup for 50 Ohms....not the case.  I have about 19dBm of return so it might be close to 50, but not dead on.

To verify it was working, I stuck a 50 terminator plug on it, noted the reference point, then looked at it with a dead-short and then a open on the LOAD/RX port.  The open and short were the same.  I then attached a R/C/L circuit that was on the end of a BNC...I used it for calibration purposes on my AMQRP Antenna Analyzer.  The resonant freq for it is around 7.1Mhz.  I checked the actual resonant freq using my MFJ analyzer and it showed 7.134.  My RLB showed it to be 7.114...but I won't whine about the difference since I was using some RG-174 in the test.

I'm using my W7ZOI spectrum analyzer as the detector and a CSM-1 for a signal source.  I have about 1.76dB of loss going through the RLB...I put -30dBm in and get -20dBm out just in case your wondering how I came up with the "dB" loss figure.

OK, I have to get up by 9am and met a sked on 80 CW and then go finish Christmas shopping for the XYL...and it is almost 3:30am now.

Jason, your my new HERO!  I appreciate all the help you have given me and now this wonderful tool to share the findings with everyone.