Re: [Drakelist] L4B (Harbach Soft Start)
I have homebrew soft starts in my L-4B and L-7 amps. They work fine and easily fit both amps. While I was at it, I installed a relay to bypass the switch contacts on the now unobtainable power switch and dropped the filament voltage to slightly below 5V. I had planned to do an article on the mods, which are totally removable without any holes, but decided against it due to liability issues. 73, John, W4AWM ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] L4B (Harbach Soft Start)
For what it's worth I don't want anything to do with the softstarts... I prefer a solid state rely to protect the on/off switch and thermisters in the filament circuit to slow up the surge to them. 73, Lee -Original Message- From: LEE BAHR To: Joe Loverti ; drakelist Sent: Thu, Mar 24, 2011 6:54 pm Subject: Re: [Drakelist] L4B (Harbach Soft Start) The soft start kits sold by Harbach are totally different for SB-220 amps and L-4B amps. My opinion is they are both way over priced. The PC layouts are done in amateur fashion and not very logical, in my estimation. (They certainly could be layed out much smaller and have much shorter trace lines to help RF from seeping into the circuit). Their "hang time" is very short, and it is fixed unless you change cap and resistor values. For about the same money, you can put in a new surplus real adjustable time delay relay plus another new 40 amp solid state relay to take the load off the "on-off" switch and it will switch "in" at the right phase angle to stop the transformer from thumping when energized. Just my opinion, but each to his own. Lee, w0vt - Original Message - From: Joe Loverti To: drakelist@zerobeat.net Sent: Thursday, March 24, 2011 4:49 PM Subject: Re: [Drakelist] L4B (Harbach Soft Start) I put a Harbach Soft Start in my Heathkit SB-200. It was wired correctly and installed per instructions – everything was double and triple checked. When I powered up the amp the Harbach Soft Start immediately when up in smoke – boy did it stink up the shack for a few days. I contacted Jeff Harbach and told him what had happened. He told me I must have done something wrong well, that is remotely possible I guess. He didn't offer to replace the kit and I didn't ask. But, I seriously doubt I did anything wrong...I've built many kits in the past and have a good track record with them. Later, on the Yahoo Heathkit amp forum, I found out Harbach Soft Starts are not without problems – a bad or sticky relay coul to begin with. Other guys have had similar problems with them. The L4B is obviously a much different animal than an SB-200... but, for what it's worth, that's my story with a Harbach Soft Start. Joe WW8X ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] L4B (Harbach Soft Start)
The soft start kits sold by Harbach are totally different for SB-220 amps and L-4B amps. My opinion is they are both way over priced. The PC layouts are done in amateur fashion and not very logical, in my estimation. (They certainly could be layed out much smaller and have much shorter trace lines to help RF from seeping into the circuit). Their "hang time" is very short, and it is fixed unless you change cap and resistor values. For about the same money, you can put in a new surplus real adjustable time delay relay plus another new 40 amp solid state relay to take the load off the "on-off" switch and it will switch "in" at the right phase angle to stop the transformer from thumping when energized. Just my opinion, but each to his own. Lee, w0vt - Original Message - From: Joe Loverti To: drakelist@zerobeat.net Sent: Thursday, March 24, 2011 4:49 PM Subject: Re: [Drakelist] L4B (Harbach Soft Start) I put a Harbach Soft Start in my Heathkit SB-200. It was wired correctly and installed per instructions – everything was double and triple checked. When I powered up the amp the Harbach Soft Start immediately when up in smoke – boy did it stink up the shack for a few days. I contacted Jeff Harbach and told him what had happened. He told me I must have done something wrong well, that is remotely possible I guess. He didn't offer to replace the kit and I didn't ask. But, I seriously doubt I did anything wrong...I've built many kits in the past and have a good track record with them. Later, on the Yahoo Heathkit amp forum, I found out Harbach Soft Starts are not without problems – a bad or sticky relay coul to begin with. Other guys have had similar problems with them. The L4B is obviously a much different animal than an SB-200... but, for what it's worth, that's my story with a Harbach Soft Start. Joe WW8X -- ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] L4B (Harbach Soft Start)
I put a Harbach Soft Start in my Heathkit SB-200. It was wired correctly and installed per instructions – everything was double and triple checked. When I powered up the amp the Harbach Soft Start immediately when up in smoke – boy did it stink up the shack for a few days. I contacted Jeff Harbach and told him what had happened. He told me I must have done something wrong well, that is remotely possible I guess. He didn't offer to replace the kit and I didn't ask. But, I seriously doubt I did anything wrong...I've built many kits in the past and have a good track record with them. Later, on the Yahoo Heathkit amp forum, I found out Harbach Soft Starts are not without problems – a bad or sticky relay coul to begin with. Other guys have had similar problems with them. The L4B is obviously a much different animal than an SB-200... but, for what it's worth, that's my story with a Harbach Soft Start. Joe WW8X ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] L4B (Harbach Soft Start)
The relay should drop out after a second or so, depending upon the size of the R/C combination. If it dosen't , either the relay is hanging up for some reason or the R/C combo is wrong for the desired time. Also, check the input voltage to the R/C combo. I don't have the paperwork in front of me and I can't recall what the viltage should be. BE CAREFUL in there! 73, John, W4AWM -Original Message- From: Woody To: Drakelist@zerobeat.net Sent: Thu, Mar 24, 2011 10:59 am Subject: [Drakelist] L4B (Harbach Soft Start) Hello again, I installed the Harbach soft key, and power supply refurbish kit and also the soft start, it all works great except for the soft start which does not kick in as it should. You do not hear the click as you should and the 25 ohm 25 watt resistor gets very hot as a matter of fact we left it on too long and popped the resistor, I replaced it with a new one and it is still heating up, I think the relay is bad from the factory, we checked and triple checked the wiring and it is exactly like his diagram. I don't know what else it could be. Any thoughts?? Thanks Again Woody (KO4BG) ___ rakelist mailing list rakel...@zerobeat.net ttp://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] L4B (Harbach Soft Start)
*Hello again, I installed the Harbach soft key, and power supply refurbish kit and also the soft start, it all works great except for the soft start which does not kick in as it should. You do not hear the click as you should and the 25 ohm 25 watt resistor gets very hot as a matter of fact we left it on too long and popped the resistor, I replaced it with a new one and it is still heating up, I think the relay is bad from the factory, we checked and triple checked the wiring and it is exactly like his diagram. I don't know what else it could be. Any thoughts??* *Thanks Again* *Woody (KO4BG)* ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist