SB-221 for K3 need some help.
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Hi Guys,
I found out this week that K3 is good with Heathkit SB-220 amps, all you need to do is connect a shielded RCA cable between the units - how easy is that? !!! I also found out that UPS had shattered the bandswitch on the sb221 I recently received and Heathkit is no longer around to get parts from. hi. If anyone knows where I can get a bandswitch wafer for the input coil selection I may be able to use this amp I bought. ;-) Thanks, Don _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Re: SB-221 for K3 need some help.
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Don, there isn't a diode across the relay coil in an SB220 - so there
may be a nasty back emf voltage on key release. Also, the K3 maximum keying delay is 20 mS, will the relay in a SB220 switch in that time? I don't want to dampen your enthusiasm, but old linears were designed for relay contact switching and generally were slow on change over... They can be modified, but in standard format may not work too well. 73 Dave, G4AON K3/100 #80, Acom 1000 -------------------------------- I found out this week that K3 is good with Heathkit SB-220 amps, all you need to do is connect a shielded RCA cable between the units - how easy is that? !!! _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
RE: SB-221 for K3 need some help.
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In reply to this post by Don Rasmussen
> I found out this week that K3 is good with Heathkit > SB-220 amps, all you need to do is connect a shielded > RCA cable between the units - how easy is that? !!! Are you sure? Most of those amplifiers had high voltage PTT circuits. If I recall correctly the TR relay is a 120V 3PDT unit. You may need a buffer or soft-key circuit in your amplifier to make it safe with the K3. > If anyone knows where I can get a bandswitch wafer for > the input coil selection I may be able to use this amp > I bought. ;-) At one time Harbach Electronics www.harbachelectronics.com had replacement wafers for the Heath amps. Check with Jeff. He's also a good source of a "soft-key" circuit for the older amps. > -----Original Message----- > From: [hidden email] > [mailto:[hidden email]] On Behalf Of Don Rasmussen > Sent: Sunday, August 31, 2008 1:19 AM > To: [hidden email] > Subject: [Elecraft] SB-221 for K3 need some help. > > > Hi Guys, > > I found out this week that K3 is good with Heathkit > SB-220 amps, all you need to do is connect a shielded > RCA cable between the units - how easy is that? !!! > > I also found out that UPS had shattered the bandswitch > on the sb221 I recently received and Heathkit is no > longer around to get parts from. hi. > > If anyone knows where I can get a bandswitch wafer for > the input coil selection I may be able to use this amp > I bought. ;-) > > Thanks, > Don > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
RE: SB-221 for K3 need some help.
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My old SB-220 works just fine with my K3 on CW.
Yes, the SB-220's key line is 120 VDC. The kind that will make you let go real quick if you accidentally grab it. The K3 doesn't mind it. The K3's Key Out is rated for +200V at 5 Amps. The stock SB-220 won't do QSK, of course. Set the K3 to semi-breakin with a hold delay long enough to keep the amp keyed between characters, and you're good to go. FB 73, john WA1ABI > > > > > I found out this week that K3 is good with Heathkit > > SB-220 amps, all you need to do is connect a shielded > > RCA cable between the units - how easy is that? !!! > > Are you sure? Most of those amplifiers had high voltage PTT > circuits. If I recall correctly the TR relay is a 120V 3PDT > unit. You may need a buffer or soft-key circuit in your > amplifier to make it safe with the K3. > > Elecraft web page: http://www.elecraft.com Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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>The K3's Key Out is rated for +200V at 5 Amps. Inside the K3, is Key Out a relay or solid state? 73, Hank, W6SX Mammoth Lakes, California Elevation 8083 feet in John Muir's Range of Light _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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W6SX Hank Garretson wrote:
> >> The K3's Key Out is rated for +200V at 5 Amps. > > Inside the K3, is Key Out a relay or solid state? It's an IRFI630 MOSFET. -- 73, Vic, K2VCO Fresno CA http://www.qsl.net/k2vco _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Hank Garretson
Solid state.
73, Eric WA6HHQ _..._ -----Original Message----- From: W6SX Hank Garretson <[hidden email]> Date: Sunday, Aug 31, 2008 8:52 am Subject: [Elecraft] K3 Key Out To: <[hidden email]> >The K3's Key Out is rated for +200V at 5 Amps. Inside the K3, is Key Out a relay or solid state? 73, Hank, W6SX Mammoth Lakes, California Elevation 8083 feet in John Muir's Range of Light _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
RE: SB-221 for K3 need some help.
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In reply to this post by Joe Subich, W4TV-3
Hi Joe & Don:
> > I found out this week that K3 is good with Heathkit > > SB-220 amps, all you need to do is connect a shielded > > RCA cable between the units - how easy is that? !!! > >Are you sure? Most of those amplifiers had high voltage PTT >circuits. If I recall correctly the TR relay is a 120V 3PDT >unit. You may need a buffer or soft-key circuit in your >amplifier to make it safe with the K3. The T-R output MOSFET in the K3 is rated at 200VDC at around 5A, so it should not be much of a concern for switching. Additionally, the MOSFET is diode-protected against reverse spikes from the relay it's keying. HOWEVER... this having been said, were it me, I'd add an (internal) Lo-voltage keying interface, like that offered by Harbach, to change the T-R keying voltage presented by the SB-221 from 120VDC to around 2VDC and maybe a couple mA of current. Pretty economical and easy to install, and worth the effort to install. Any T-R keying interface regardless of what you use (OEM or 3rd party) will not, as Joe has pointed out, change the keying speed of the open- frame T-R relay. That is a separate problem which CAN be addressed with replacing the OEM relay with a high-speed power reed relay (drive input) and a vacuum relay (RF output). But you CAN significantly improve the transition speed of the relays IF you NEED the feature. 73, Tom N0SS 73, Tom N0SS _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Hi all,
I am from the old school of thinking that sometime I am going to need to key an AC relay in an amplifier and prefer to make a VERY simple interface and generate a set of dry contacts. That way regardless of the keying gender, you are safe. It keeps ground current loops out of the picture too. Mel K6KBE --- On Sun, 8/31/08, Tom Hammond <[hidden email]> wrote: From: Tom Hammond <[hidden email]> Subject: RE: [Elecraft] SB-221 for K3 need some help. To: [hidden email], "'Don Rasmussen'" <[hidden email]>, [hidden email] Date: Sunday, August 31, 2008, 10:10 AM Hi Joe & Don: > > I found out this week that K3 is good with Heathkit > > SB-220 amps, all you need to do is connect a shielded > > RCA cable between the units - how easy is that? !!! > >Are you sure? Most of those amplifiers had high voltage PTT >circuits. If I recall correctly the TR relay is a 120V 3PDT >unit. You may need a buffer or soft-key circuit in your >amplifier to make it safe with the K3. The T-R output MOSFET in the K3 is rated at 200VDC at around 5A, so it should not be much of a concern for switching. Additionally, the MOSFET is diode-protected against reverse spikes from the relay it's keying. HOWEVER... this having been said, were it me, I'd add an (internal) Lo-voltage keying interface, like that offered by Harbach, to change the T-R keying voltage presented by the SB-221 from 120VDC to around 2VDC and maybe a couple mA of current. Pretty economical and easy to install, and worth the effort to install. Any T-R keying interface regardless of what you use (OEM or 3rd party) will not, as Joe has pointed out, change the keying speed of the open- frame T-R relay. That is a separate problem which CAN be addressed with replacing the OEM relay with a high-speed power reed relay (drive input) and a vacuum relay (RF output). But you CAN significantly improve the transition speed of the relays IF you NEED the feature. 73, Tom N0SS 73, Tom N0SS _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Re: Re: SB-221 for K3 need some help.
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In reply to this post by Dave, G4AON
As far as the bandswitch is concerned, a good source for them are
the guys who do the 6-meter conversions for SB-220s and SB221s, since they remove the whole bandswitch assembly. Check with Lou at King Conversions ([hidden email]). He may be able to help you out. Lou does a great job with his 6-meter conversions, BTW. I'm using one with my K3, but part of his conversion is installing a solid-state buffer for the T-R line, which in the unmodified SB-220 switches 120VDC. Do NOT connect an unmodified SB-220's T-R switch line directly to the K3's T-R switch output jack. Your K3 will NOT be happy. Bill W5WVO ----- Original Message ----- From: "Dave G4AON" <[hidden email]> To: <[hidden email]> Sent: Saturday, August 30, 2008 11:50 PM Subject: [Elecraft] Re: SB-221 for K3 need some help. > Don, there isn't a diode across the relay coil in an SB220 - so there > may be a nasty back emf voltage on key release. Also, the K3 maximum > keying delay is 20 mS, will the relay in a SB220 switch in that time? > > I don't want to dampen your enthusiasm, but old linears were designed > for relay contact switching and generally were slow on change over... > They can be modified, but in standard format may not work too well. > > 73 Dave, G4AON > K3/100 #80, Acom 1000 > -------------------------------- > > I found out this week that K3 is good with Heathkit > SB-220 amps, all you need to do is connect a shielded > RCA cable between the units - how easy is that? !!! > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Re: SB-221 for K3 need some help.
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In reply to this post by Don Rasmussen
The K3 will handle the open-frame relays in SB-220-type amps but open-frame relays will not close reliably within 20ms.
Some contest logging programs (CTWin for example) enable up to 250ms delay which is fine for most old amps, but don't attempt to use your paddle via the K3 internal keyer. A work-around is an external keyer via the computer - for the casual operator, a foot-switch is highly recommended. 73, Ken ZL1AIH (@ZM1A in contests) _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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