FT-897D for SOTA

In reply to M0MTJ:

It’s a bit like the saying “there are old pilots and bold pilots but no old, bold pilots”. Same goes for PSUs, “there are cheap PSUs and good PSUs but no cheap, good PSUs.”

You really need to see what you are getting when it comes to these things. The manufacturers skimp on heatsinks, component specs, wire thickness, protection, noise suppression etc.

I’ve not looked at linear PSUs for a long time so I don’t what’s on sale anymore. Really if you want a proper supply you want a industrial frame supply rather than something for the amateur market. If you can lift it, then it’s probably got an under-rated transformer! Farnell, Advance, Gould all made wonderful PSUs. I don’t know if they make non-amateur linear supplies anymore so any you find may be old and the caps may need a dose of TLC.

I have an old Revex P300 linear. Seems to be well made and mine is 19 years old and going strong. The fan controller failed so I made my own PWM controller out of a dual 555 and a BFY51. All of them I’ve seen seem to be well made and used decent components. I’ve seen 4, 2 had fan failures. Classic 723 + 2n3773 pass transistors. Of course 2nd hand ones will be old now so treat with care.

I’ve also got a Microset PTS124. Bought this in Friedrichshafen in 2004 I think. Small, switching, doesn’t get hot. Decent construction, doesn’t make RF noise I can find. Fully protected. I paid £54 for mine direct from Microset at the show. WS sell them now for £102 inc Essex Tax. I’m sure you can better that price with no effort.

I’ve a Maplin 10A linear I acquired 22years ago. Still chugging away and used as a car battery charger now. 723+2n3055 design.

But really you should get a modern switcher. Noise is a thing of the past and they run cool. Make sure if has an over volts crowbar as well as over volts shutdown of the switching controller. :wink:


In reply to MM0FMF:

Thanks Andy, Most helpful and all noted.

You’re quite right about “there are old pilots and bold pilots but no old, bold pilots”. Same goes for PSUs, “there are cheap PSUs and good PSUs but no cheap, good PSUs.”

73, Mike.

In reply to G8ADD:
Lesson: both reverse and overvoltage protection are a good


But Yaesu do provide these facilities in these radios - unfortunately they are also the PA devices!!! Rather expensive fuses.

I would concur with everyone - make sure your rig NEVER EVER sees more than 16 volts otherwise it is “Good Night Sweetheart” for the main microprocessor, and for reverse voltage just a large diode AND real fuses, please!

Barry GM4TOE

In reply to OK1FFU:

Hi Petr,

I am not sure what bands you work, but the 857 will distort / FM on 2m and 70cms SSB when the battery volts drop. When my 3S LiPOs get below 11V then the fun starts! I’m sure several chasers will recall those contacts! No sure issue with a big NiMH in circuit. :slight_smile:

73, Gerald G4OIG

In reply to MM0FMF:

If I didn’t know of the abomination that is the EP925 (sold under many names and model numbers) I’d find it hard to believe that anyone could get away selling such junk. Under rated components, questionable build quality and no over voltage protection… they’re cheap for all the bad reasons.

Yes, beware of this design! The worst problem is the voltage spike on switch on - around 18V when the PSU is set to around 13.2V. I have one and it took out the transistor in my 180W BNOS linear which has a tight base - emitter voltage limit. Cost me 40 GBP for a replacement and I was fortunate to get one at that price!

73, Gerald G4OIG

In reply to G4OIG:
Hi Gerald.

“I wholly agree Andy about the 817 being fiddly with gloves - in my opinion, it is nigh impossible, so I always abandon my gloves when it is cold to operate and then have great difficulty getting them back on when my hands are cold and damp”

I use ‘flap-over’ mitts. The type used for shooting. Ideal for use with the 817 and writing on the log etc.

Cheers es nce to wrk u SS-208 last week.

Jack (;>J

In reply to GM4COX:

Many thanks for the suggestion Jack. I hadn’t realised that you can get fingerless mitts with covers. Fingerless mitts alone would be no good for me as I suffer from Reynauds, so these look like being an ideal solution. I have ordered a pair to try. No doubt winter is just around the corner. :slight_smile:

Pleased to have the chat from SS-208. I tried FM from SS-133 but no-one was heard.

73, Gerald G4OIG

In reply to G4OIG:

A pair of Dachstein mitts hanging from your sleeve so that you can slip a hand into them, in conjunction with the good old Miller Mitts - a combination that I know from experience will work at -30C!


Brian G8ADD

In reply to GM4COX:

Try thin latex gloves, they insulate much better than you might expect.

In reply to MW6DHN: We use all three Yaesus in our various activities, and while I greatly enjoy the 897, it is very large and bulky compared to an 857 and has not left my desk. The 857 with an external LIFePO4 battery pack is my favorite SOTA setup for ssb. I do use an 817 from time to time when travelling for business as it fits nicely in my laptop bag. Scott W7IMC