[Amps] Bypass SWR RJ1As

[David Craig]

    Hello All,

    Looking for input/advice regarding "tuning" the relays of my latest homebrew GS35b 50 MHz amp.  Using a pair of RJ1As (used but hipotted good, I presume MRI pulls) for RF switching.  In other amps I have been able to "tune" out slight "thru" SWR issues (driver thru, amp in standby) using silver micas to ground.  Projects that worked fine for me were K5AND's Schrack relay board using a 10pf to ground, an SB220 using ~68pf to ground...  
    This is my first time trying vacuum relays & it "appears" I have capacititive reactance, I think?  With just RG214 to the relays & RF in/out connectors, I get a whopping 3 to 1 SWR with amp in bypass.  I tried various silver mica caps, and low value trimmers to ground from the NC to NC coax connection- lowest bypass SWR I can get is 1.3-1.4 to 1 with a single 47pf silver mica to ground.  This is usfficient to allow the driver to put out 100w with the amp in bypass mode but isn't "right."  I'd much prefer a flat SWR.  
    I am a bit fearful of trying a small inductor to ground, don't want to hit a resonance at 6m & burn out my exciter.  I can't find any RF impedance data on the RJ1A but assume that it must be a fair bit off 50 ohms at RF, or maybe I have a bad relay?  Anyone have this problem, and if so how did you solve it?  Is is safe to use a parallel inductor to ground with my driver so long it tests OK at 50MHz on my MFJ 259?  
    My relay commons are fed to RF in & out & NC leads connected to each other with about 2.25" of shielded/grounded RG214 between the relay posts.  Both relays are in the cathode pressure compartment, not in a shielded box (which doesn't present a problem with amp RF out).  Have also (of course) the cathode choke & separate bias choke in the compartment, along with a sefl-designed pi-input tuning network.  The screwed-up planning I did on the cabinet makes it difficult to increase the NC to NC cable length, but could that help?  I'd am curious if this is a common issue with RJ1As.  Any input appreciated.

    Thanks & 73
    Dave N3DB