[Amps] Automotive Relays

[Jim Thomson]

Date: Sun, 8 Aug 2010 19:34:09 -0800
From: Jim W7RY <w7ry at inbox.com>
Subject: Re: [Amps] Automotive Relays

You and them must have back luck! 

I'm using a BN-86 on the TH7 and run RTTY contesting at 1500 watts. Never had an issue in the 8 years it's been up. The aftermarket baluns all seem to cause the SWR to go up.... At least on the TH7... 

When I installed the BN-86, the swr curve was just like the one in the manual. 

I can't explain it. Neither can others. 

73 
Jim W7RY 

## I had 3 of those BN-86's, back in the mid 70's.     A single 4-1000 with just 1900w pep out on ssb  smoked all 3 of em.   I had one on a 204BA, one on a 40m sloper,, and the 3rd was on a 80m
inverted vee.    All has flat swr.   We took them apart, and they looked like the formvar/nyclad / etc,  was off the magnet wire inside.   The insulation on the magnet wire was clean off in
several places.   The rod it was wound on was reduced to cracks, and charcoal.   Several more here in town bit the dust.  A fellow just north of me has a TH-7 and BN-86, of recent vintage. He 
only has a SB-220, and his finally gave out after 6  years. 

##  which aftermarket baluns caused your swr to rise ?     I have not had any problems with the small F-12,  1' long baluns...which is just a bead balun + 303 coax. 

## apparently the ...'newer'   hy-gain  BN-4000   consists  of  real small  type-77 beads slid over RG-303.  They rate that balun at 2 kw cxr, CCS..a nd 4 kw pep. 

Later... Jim  VE7RF