Discussion in 'Amplitude Modulation' started by W7TFO, Jun 29, 2021.
Has anyone experienced this?
We're planning on installing some of these units.
I faintly recalled Don may have done something with one of those things and found this:
I have installed 3 seperate units at my QTH, all manufactured by a company named Pioneer. 2ea 18,000btu and a 36,000 btu unit. I have not had any noise or RFI issues on HF yet. I have not tested it on VHF or above.
Don installed a unit manufactured by Mr. Cool in his shack. IIRC, he was experiencing a very
small increase in background noise on his receiver but only when he was on his indoor magnetic loop antenna located in the same room as the indoor unit.
That's correct. The loop is primarily resonant on 160m, although I can make it work on 75m but rarely do. The rise in background noise is quite noticeable, like a white noise, not a buzzing sound, but raises the noise floor probably 10-15 dB. Since I very seldom use the loop in summer months when the a/c is in use, it hasn't been a problem. No detectable noise when listening on any band with the Beverage or the transmitting antenna.
I never use the mini-split in heating mode, since a heat pump rapidly loses effectiveness as the temperature drops below 40°. Any machine with moving parts wears out with use and age, so I save mine for cooling only, which should allow it to last at least twice as long as running it year round for cooling and heating. Forcing it to grunt and groan to extract what little heat there is in the cold outside air has to be hard on the mechanism, and you still may need auxiliary resistance type electric heat when the temperature dips. The only kind of heat pump I would consider using would be geo-thermal. Some of those run the heat exchanger as a pip along the ground, buried below the frost line, less costly than running it down a deep well (the best method), thus making it more affordable. Right now, I heat the shack with propane $$$.
Following this thread as I really need to add additional AC to my radio room. I'm wondering how much ambient noise is added to the room by the AC blower. Wondering if the mic will pick up blower fan noise from across a 12 foot room (thinking about a 12K BTU unit). Primarily concerned with my AM rig, using an EV RE-27ND mic, which is pretty sensitive. Anyone have any experience with raised ambient noise levels from the mini split blower?
I have had a Dankin system for over 2 years. It has two 12,000 btu registers, one directly above my Ham Desk on the secord floor. I have has no RFI problems whatsoever...
The 24,000 BTU minisplit is extremely quiet (acoustically). I can just barely hear it running. The 40 y.o. window unit I had mounted in a hole in the wall, that I replaced with the mini-split, was so loud I often turned it off before going on the air, even during hot weather.
The Mitsubishi mini-split units are extremely quiet (RFI clean)
The modern mini-splits have an indoor sound rating in the 40's dB.