[Heathkit] Chinese 572B's in a SB200

[Steve Beveridge]

Hi Carl,

The 572B tubes which require modification to the bias circuitry of the
FL2100 amp are the Svetlanas. Have a good look at the info on RF Parts
website - there's a good comparison of the tubes. The Svetlana is nowhere
near up to the specs of the old USA-built 572B's.

I'm in VK land and recently got hold of a pair of the Taylors that RF Parts
are selling. They are still made in China, but use some US components and
are supposed to be built to the original Taylor 572B specs. From memory,
they were about $US45, while they had other Chinese 572Bs for $US39. The
Taylors also come with a 12 months guarantee. RF reckon they have had
excellent results with the Chinese-built Taylors.

I'm been doing a total rebuild of a SB-200 which had been badly water
damaged  - unit had been sitting in water for some time - so still not quite
up to trying the Taylors yet, but hopefully shortly.

>From what I can gather, the new generation Chinese tubes are supposed to be
a lot better than their earlier efforts.

Good luck with the decision!

Cheers and 73
Steve VK2XWL
Newcastle, Australia


----- Original Message -----
From: "km1h" <km1h at jeremy.mv.com>
To: <heathkit at mailman.qth.net>
Sent: Monday, October 10, 2005 10:41 AM
Subject: [Heathkit] Chinese 572B's in a SB200


I recently bought some from that auction site and I cant seem to tame them
down. Ive used other Chinese 572B's without problems but I recently used up
my stash.

I remember problems using some tubes in the Yaseu FL2100 series, relating to
the import tubes requiring a different operating bias. Anybody able to
relate that to Heathkits?

Anybody have a good pair of USA tubes for sale??

Carl
KM1H