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Anyone have a cell filter for the 847? -- Dirk Esterline PHS Spanish

Hi folks, if any of you in the UK need a replacement power switch these are available from cpc.co uk with the order number of - SW04793, these should also be available from Farnell sites in other Countries. Leighton. GW3FSP.

This is the continuation of fixing the FT847 VHF second channel fault that we’d tracked down to a faulty switching transistor pair, Q2016, that provides the supply rail for the VCO, MO2002. John received a few of the FMC3 transistor pairs from AliExpress and with much profanity and considerable magnification I managed to replace the duff one. I found it best to simply crush the old part in-situ then de-solder the remaining fragments, clean up the board and put the new one in place. It seemed we’d solved the problem as we could see the voltage switching at the output pin 2 of the 5 pin switching device. Unfortunately the voltage never reached the VCO....mystery.... there is only a length of track and 100 Ohm smd resistor between the two parts! The track checked out ok as did the resistor, so where the heck did the voltage go! There had to be a short at the VCO end grounding that supply line. There are only 3 components that could be causing this (I think), the VCO, C2061 10uF smd cap and C2063 .001uF. Well, at this stage we gave up for the day, it was time to put the board back and take the wife out. We’ll continue the fault finding later this week. I’m just hoping it’s not the VCO, but I fear the worst. Paul, G0odp Virus-free. www.avast.com

Getting VERY close now. Today we double checked the voltage on TP2002 for the VHF VCOs and as before it seemed fine for the Low VHF band (up to 139.99MHz) but clung to 7v for the high VHF band (>140MHz). So, we then checked the switching voltage actually at both ends of the tracks, so at MO2001 and Q2015, they were fine switching at the 139/140MHz boundary. HOWEVER, the MO2002 and Q2016 pair did not show a changing voltage at the 139/140MHz boundary. So we checked the other side of Q2016, pin 4 and we could see the switching voltage there, so using our great powers of deduction (yeh right!) Q2016 has to be a bad-un!!!! This is an FMC3A (or FMC3AT148), so we are checking suppliers now and will probably use Aliexpress (everyone else want an order of 3,000) sadly with a few weeks delay, but it’s a cheap solution and far better than having to source the VCO! I guess our big hope is that the VCO is working fine and that it didn’t cause the switching transistor pair to blow....fingers crossed. Guys, thanks again so much for all your support and my local friend Tex for explaining the mysteries of the PLL circuit. I’ll update you when we replace the part and try the radio. 73. Paul, G0odp _._,_._,_ Virus-free. www.avast.com

Hi, I am trying to repair an FT847 for a friend, the rig works perfectly on all bands except 2mtrs. On 2mtrs nothing is heard or transmitted; it won’t hear my sig genny at all. I have injected a signal directly into J3001 144RX on the RF Unit and that isn’t heard, I should add that the frequency display is working perfectly. Next I examined the Local Oscillator signal on J3010, we checked this for 70cms (which we knew was working) and could see the signal 45MHz above displayed frequency, all well and good. I then switched to 145MHz and couldn’t find the LO at all on my spectrum analyser. Now this is the ‘fun’ part, when I tuned below 140Mhz, say 139.999MHz a local oscillator signal appeared 45MHz higher, as expected, but would switch off as soon as I reached 140MHz!!!!! We have tried a CPU reset but that didn’t make any difference. Has anyone got any suggestions, we’d really appreciate some inspiration. Sincere thanks. Paul G0ODP, John G0KFM Virus-free. www.avast.com

The following files have been uploaded to the Files area of the [email protected] group. /FT 847mod by Yeasu.pdf By: gw3fsp <gw3fsp.ldavies@...> Description: Band modifications for 847 frequencies

So I pulled the bottom cover off my newly acquired FT-847 to check if it had the optional filters installed. (it did not) I see the open space for the CW filter, 4 pins on each end. I also see the Murata SSB (stock) filters installed, 4 pins on one end and 3 pins on the other. They appear to be identical. My question is this - Are the SSB filters called '7-pole' because they have 7 pins to connect them? Will a Collins 8-pole SSB filter work there? Also - What is the difference between the Collins filters and the Inrad? Inrad apparently has stopped manufacture and is pretty much out of stock, so a used filter is probably my only option here. Which filters fit/work for SSB? Can I install an 8-pole filter in the 2 spaces (TX & RX)? Thanks in advance Micky K1XH

Hi All I have been looking in the manual but can find any refence to SWR display. I have the FC-20 connected but get no indication of SWR reading? Thanks

Hi Mickey, Can I ask you , is your ft 847 a C2 model if it is, then 4 meters comes as standard. Check your serial number, that’s serial numbers after 9E so that means May 99. 73’ Paul Sent from Mail for Windows 10

I know this may have been asked before, but I couldn't find the answer...Is there a free memory manager app? Something that would allow a user to pre-program the memories then upload to the radio? I am familiar with the RT Systems software, but would rather spend the cash on better antennas. What about an app to save the menu contents? Does such a thing exist? Micky K1XH

Hi All, Got a 2002 model, still working great. The MEM/VFO CH encoder got flaky a 2-3 years ago, would skip and jump around. Got TWO replacement encoders from Yaesu at that time, put them in a box somewhere. Finally got a moment of time to try this fix. Top and bottom covers off, knobs off, front panel off, small pile of nuts washers and screws (was easy to put them all back in the right place). Unplug a few cables, pry the sheet metal open, and out popped the front control PCB. Did NOT try to "clean" the LCD or plastic screen, they were good enough. Did blow out a bit of dust and lint from the chassis. Un-soldered the encoder, but did NOT put in a new one. Pried up 4 small metal tabs on the old encoder, and pulled it all apart. Q-tips, alcohol and contact cleaner got off some old lubricant that was mostly just a bit sticky. A new tiny dab of Ox-gard on the contact fingers and contact wheel. Bent the tiny tabs back down and soldered the encoder it back in to the PCB. Put the whole mess back together. Did NOT break a single thing, or have any left over parts! MEM/VFO CH encoder now works just like new. Doubled up the power switch contacts with a few tiny bits of wire while I was in there. I bet I could do this 2-4 times before the encoder tabs broke, or a solder pad lifted from the board. Good enough for a 18 year old radio. If I had bothered to use the new encoder, I would save the old one for for repair and replacement the NEXT time. The new encoder I got from Yeasu has the tactile detents. There was a small spring plate on the encoder that could be removed if you wanted to use the encoder for the free spinning SUB-TUNE position. Resources: https://www.qsl.net/wb5apd/ft847pwrsw.html - talks about the power switch, but good info on dis-assembly. http://jvgavila.com/ft847.htm - some good pictures of the chassis insides. 73, Eric / ke6mlf

Greetings all. Is there a way to determine the year of manufacture of the radio from the serial #? Which radios/years do not have the bidirectional CAT control? Is there an easy way to tell the difference from the serial #? Micky K1XH

HI My previous radio was the 847 early production run and yes Yaesu did offer to do the fix free of charge. I live in Canada and only had to send the rig to my local shop. After the mod, all was well. I really liked that radio and still have it. Good luck and 73 Joe VA3JLF Sent from Mail for Windows 10

For those technically inclined: The available pdf service manual (technical supplement) is version 1.2. There must be a version 1.0 or 1.1. My RF board layout (backside) does not match the manual (or the schematic). Specifically, C3018 has a three leaded device (like a SOT-23) hooked to it (and it is shorted). It's not Q3004 - that is a four leaded device. There is no UHF reception and this is the reason why - signal is shorted to ground here. thx, Alan, W4FBI

Next to the 3.3v lithium battery is S1001 switch. Position is 'OFF" or 'Backup' Can't find any info on it. What position should it be in for normal operation? thx Alan, W4FBI

I just acquired a used FT-847 and plan to use it for VHF/UHF work including getting into satellites. I have one question. I plan to get preamps and am looking at 2M and 75cm mast preamps from Advanced Receiver Research. They require 200mA each. The Yaesu manual says it can supply 300mA to the VHF AND/OR UHF connectors. I am confused if this a total for both connectors conbined or 300 mA each? Looking at the schematic I see there is one current limiter for both connectors so I assume this is a total number. I am wondering if anyone has run into this? Thanks, Bruce, WB6IZG

FT847 QRP or QRPp for TRANSVERTER HI I have to use a low power output, with no possibility of high power error, to drive an external transverter for 13 and 23cm or QO100 upconverter. I would not always want to have the low power but have an extra output for the transverter and use its original PL/N output, still the maximum power of 50w to V & U and use a QRP/QRPp output for the transverter independently and securely? Any advice on how this can be done on the FT847? Thank you and greetings 73

Hi FT847 users I have a question: I have a FT847 that will transmit immediately when I turn ON the TRX not always but nearly always Now and then the TRX works fine for some time , then suddenly starts to transmit on its own Some info: MOX knob is NOT the cause Nothing is connected, no microphone, only the antenna and power cable , so no external cause No short inside the 8P Microphone connector Did anyone see this problem before ? please let me know here in the FT847 Group or DIRECT via pa3dol@... Many thanks in advance Best 73 Sjoerd PA3DOL

I have a fantastic rig but the microprocessor is not working well means cant hold the settings and cannot return to factory settings all values are reset after power off and switched on later. wonder anyone has a broken rig where the pcb containing working microprocessor is available. I really wanted to get this rig u and running. Please let me know if anyone has a spare PCB. 73’s Glit M0HPF glitsun@...

Yaesu uses a 5 pin mini DIN plug on the FT-847. This plug is used as a connector for a cable to key a linear amplifier. Actually they use the same connector for HF, VHF, and UHF amps. I had a very hard time finding a connector that fit. Some (I assume from China) did not fit right. I found some that DO fit fine. I assume they are American, or possibly Japanese. In any case, they do fit OK. In order to get any kind of a decent price I needed to buy ten. I need one to use on the rig, and want to keep one spare. That leaves eight available, for sale. They are $5 each (yes, I will end up making about a 16 cent profit!), plus shipping. I can ship one, two, or three via first class mail for $4.60. It is quite possible that these 5 pin mini DINs are used on other rigs beside the FT-847. Please let me know how many you want. Thanks. 73, Ken, W8EK Ken Simpson E-mail to W8EK@... or W8EK@... Voice Phone (352) 732-8400 . .