- strange signal spittler; bad reception on last tv in a row. - 3 Updates
- Excessive motor current draw question - 2 Updates
- Baku 601D hot air reflow station - warning - 1 Update
| Ian Jackson <ianREMOVETHISjackson@g3ohx.co.uk>: Mar 13 10:24PM In message <b5946flifqd47cfb5j4eqhtb3gdb3cp5e1@4ax.com>, micky <NONONOaddressee@rushpost.com> writes >>Probably 90db isolation between output ports >>KenW >That accounts for it. Thanks. 90dB is highly optimistic. 40 dB would be more typical (but still adequate), and maybe a bit less at 2GHz. If they do mean 90dB, it's probably the screening factor (a measure of signal leakage and ingress). 90dB would be good. -- Ian |
| Clifford Heath <no.spam@please.net>: Mar 14 12:13PM +1100 On 14/3/20 9:24 am, Ian Jackson wrote: > adequate), and maybe a bit less at 2GHz. > If they do mean 90dB, it's probably the screening factor (a measure of > signal leakage and ingress). 90dB would be good. Could be 90dB/Hz? CH |
| Tony <nomail@nospam.com>: Mar 14 01:19PM +0800 On 23/02/2020 10:03 pm, micky wrote: > 1) Any reason to buy a gold-plated splitter? Outdoor use? > 2) Besides the extra $2 charge, is there any reason to NOT buy a > power-passing splitter if I'm not sending any power? Just found this one with google. It has 90dB RFI shielding: https://www.computercablestore.com/coaxial-splitter-catv-f-type-3-way-1ghz-90db#full-description Now it makes sense -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus |
| etpm@whidbey.com: Mar 13 03:07PM -0700 I have a Tiawanese manual lathe with a 3 phase 3hp motor. I run my shop on a phase converter. I have a CNC lathe with a 15hp spindle and a CNC mill with a 10hp spindle. Other machines too but it's these 3 that make me wonder. When the CNC lathe spindle is starting it starts fast. Bang! The mill also starts fast, but not quite as fast. Both of these machines can start at the same time with no problems. Even when the chuck is on the lathe. The chuck wieghs about 50 lbs. so it is a lot of inertia to spin up. But if I start the 3hp lathe at the same time as the CNC lathe it sometimes faults the spindle drive on the CNC and it shuts off. The crappy little motor never runs hot enough to smell, and I've had the machine for about 20 years. It does run rough though and always strains to start. When starting the manual lathe in the highest gear it takes longer to spin up to 1150 rpm than the CNC lathe takes to spin up to 5000 rpm with the 50 lb. chuck. So what could make this motor draw so much current? Thanks, Eric |
| John-Del <ohger1s@gmail.com>: Mar 13 07:20PM -0700 > could make this motor draw so much current? > Thanks, > Eric I had a big blower motor that would spin as easy and free as a child's pinwheel in a gentle breeze, but virtually lock up when AC was applied. It would howl and struggle to build RPMs. Even after AC was cut, it was still stiff until I turned it over several times when it relaxed. And it wasn't heat either - I could switch on the motor for a split second, and it stiffened right up. There was no end play, but it had bad bearings.. |
| legg <legg@nospam.magma.ca>: Mar 13 03:42PM -0400 >cord. >. . . . of course it's still not CSA or UL. >RL The original fault was due to a fan speed control circuit failure, shorting a low-power secondary transformer winding. This would have been simply repairable, with a separate properly-sized primary fuse for the transformer. It would not have occurred, unattended, with a proper line power switch. RL |
| You received this digest because you're subscribed to updates for this group. You can change your settings on the group membership page. To unsubscribe from this group and stop receiving emails from it send an email to sci.electronics.repair+unsubscribe@googlegroups.com. |
No Response to "Digest for sci.electronics.repair@googlegroups.com - 6 updates in 3 topics"
Post a Comment