FT847 FAN replacement ...
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I have fans in my collection of spare parts.? This is of no use to you at all, because I am in UK, and you could be in Outer Mongolia for all I know. "Frank" does not give a clue to your location.? Take it out, clean it, and put it back in with a bit of thin foam over it.? The fans are generally noisy due to what the air is hitting, not the fan itself. If it is the fan, clean or replace. 40mm x 40mm.? On Fri, 11 Feb 2022, 09:45 Frank, <hb9oab@...> wrote: Where can I find a replacement fan for the FT847 and how to do it? |
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As for my FT-847, I put a resistor in series with both fans to quiet them down. About 50 ohms if I remember right. Never had a problem and it's much quieter. There was a discussion on the group about the fans quite some time ago. I saved the info - here are some of the notes: Perhaps you will find it useful. A friend of mine found a slow speed fan that moves just about as much air but does it with much less noise. Specs are as follows: Both fans size 40mm x 40mm. Original fan: UC Fan; F412R-12MB-32; DC 12V; COPAL Co. LTD, Japan; Made in Malaysia; 5400 rpm; 0.06A; 1 ball bearing and one sleeve bearing; 0.15 cubic meter/min (5.3 cfm); noise 23 dB(A). Replacement fan: Mini Kaze SY 124010L; 3500 rpm; 0.06A; sleeve bearings; 4.11 cfm; noise 14 dB(A). [Search for it on Amazon] Installing the new fan involved only cutting off the plug supplied with the fan and splicing in the plug provided with the original fan. I bought my fans from Amazon, but they seem pretty common for PC’s, so they may be available in your area locally too. The big one or front is 60x60x25 (mm) 12 VDC and the rear one is 40x40x10 (mm) 12 VDC. They were about $10 each. Be sure to look for 6 bladed fans with precision ball bearings. Also anything listed as “quiet” runs with a slower RPM and that is fine. I do lots of satellite work and have tested the rig running for days and my measurements with a digital thermometer indicated it maintained the ambient room temperature. For installation wiring, I pulled the sticker off the new and original fans and simply moved the radio’s wiring cable to the new fans, then re-applied the round sticker back on the fan. Here’s some specs from one of the fans: - Fan speed: Old: 5400 rpm; New: 3500 rpm - Fan noise: Old: 23 dB; New: 14 dB - Air flow rate: Old: 5.3 cfm; New: 4.11 cfm. 73, Richard AG5M On Friday, February 11, 2022, 09:49:16 AM PST, Greg D <ko6th.greg@...> wrote: Is the fan itself making an unusual noise, or is it just on full-speed?? It should come on at low speed (fairly quiet) whenever the radio is on.? The fan in my 767GX is stuck on full (and noisy as a result), but I presume it's the radio's fan control circuitry that is at fault, not the fan itself.? I haven't had a chance to dig into the rig to track it down further. Greg? KO6TH Frank wrote: Where can I find a replacement fan for the FT847 and how to do it? |
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Hi Greg,? there are two fans in the 847. The one on the rear panel runs continuously. The larger internal fan only becomes active in TX. Neither of them have any form of temperature control. Most of the noise from the rear fan comes from the fact it blows air against a circuit board. If the fan is unscrewed from the radio, it becomes much quieter.? One thing to note. The internal fan blows against the rear of front panel, and any dust tends to accumulate there. For the benefit of all owners, it is worth taking the cases off and? checking, and blowing any dust out. I have seen one with a 1/2" carpet of dust in front of the fan.? |
Frank
Andy Bosworth
Richard AG5M