RF ‘Return Loss Bridge’ Suggestions for the DSA815-TG user on a limited BudgetI listed below two Chinese RF Return Loss Bridge units that are available from ebay at reasonable prices that generally meet their advertised Return Loss specification of 35 dB minimum. The advantage in these two units is that they are supplied in rugged aluminum cases, and can be opened easily for tweeting/improving their return loss performance. As supplied they perform much better than the popular Mini Circuits directional coupler that a lot of the Hams are using, or even the expensive Rigol model VB1020 VSWR Bridge (a nice looking package, but with poor performance and specifications).
I’m not affiliated in any way with these suppliers, and simply wanted to offer some easy to work with suggestions for Return Loss Bridges for those that may be interested in something that works relatively well for a very reasonable investment cost.
1. This is a Chinese Return Loss Bridge for
1 to 500 MHz that is rated at -35dB Return Loss that can be purchased for about $40 USD. Although, I suggest (Item 2.) the 1 to 1,000 MHz unit below for about $20 USD more for its extended frequency range, nicer construction, and easier to work on while assembled.
Example: http://www.ebay.com/itm/NEW-1-500-MHZ-reflection-bridge-standing-wave-bridge-rf-bridge-/291539579585?tfrom=302125570443&tpos=top&ttype=coupon&talgo=undefined2. This is a Chinese Return Loss Bridge for
1 to 1,000 MHz that is rated at -35dB Return Loss that can be purchased for about $60 USD. This one is my preferred choice due to its being easier to adjust for improved performance than the 1 to 500 MHz unit above.
Example: http://www.ebay.com/itm/NEW-1-1000MHz-1GHz-reflection-VSWR-bridge-bridge-bridge-RF-SWR-bridge-/131329059012?hash=item1e93d268c4:g:RY4AAOSwr81USGVLCaution: Do not do any adjustments or tweaking if you do not have a excellent 50 Ohm Termination such as a Mini Circuits (MCL) model KARN-50-18+, N male connector, 2 Watts, DC to 18GHz, $14 each (brand new, directly from Mini Circuits). Also do not make any adjustment if your not fully familiar with a Return Loss Bridge, haven't Normalized your SA with the RLB (with a 'UUT' Open) between the TG Output and SA Input. If in doubt , don't do anything to your new RLB!
Even without any adjustments these units should perform very well for you.
Additional reference info: https://www.eevblog.com/forum/testgear/spectrum-analyzer-rigol-dsa815/msg583550/#msg583550See the (*.doc) attachment for RLB pictures and a Response Plot of the 1 GHz unit.