In addition to Rich's information, I thought I'd add in a not so obvious
source. Surplus two-way radios made by Motorola have an outstanding relay
that will easily switch the exciter side of a TR switch. The Motorola
Micor and Mitrek two-way radios are often sold at ham fleas for $25 in
bulk, less when not working. The tr relay is a high speed unit that
easily takes 100 watts rf, has an ft >500MHz. The lead coax is often
teflon or similar.
cheers
skip wv6f
nospam4me@juno.com
.
>Can the reed relay types sold by Neb. surplus (or similar) be used to
>upgrade the T/R relay on the SB-220?
>
I went to the Nebraska Web site. I saw no info on make speed, break
speed or RF current and RF voltage ratings versus frequency. . A
virtually new, unused, Jennings RJ1A vac. relay from Fair Radio Sales
costs $35. It will handle c. 3kW @ 50 ohms @ 28MHz. Two in parallel
will handle 12kW @ 28MHz. . With a suitable speedup circuit, the RJ1A
will switch in1.8mS. // New, Matsushita shielded rhodium-gold contact,
1.0mS, 150w, RF reed relays are available for $10. See my Web site.
High speed switching parts kits, including the RF reed relay, are $20
each. - the RJ1A vac. relay is not included.. See circuit in Jan. 1994
QST or see Fig. 7B on my Web site. Very few vacuum relays can switch
fast enough to keep up with modern radios.
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