Need help with my 840

I have a problem with my 840 the frequency dail has fell off, first the dail become stiff then fell of I need to replace it has anyone have any idea on how I can fix this problem so it works as it should again.

Do you mean the vfo shaft has snapped off the radio ?

no the dial has just fallen of

i have the spring a the small plastic washer i have tighten up the shaft because the was loose just dont know how to put the dial back on

do i need to buy an encoder thats if i can get

Hi Dave,

The VFO knob is attached to the VFO shaft by a small screw which is hidden under the ring of said knob.

If it helps any here's a link to the service manual and an 'exploded' view can be found towards the end pages to see how everything attaches :-

https://www.radioamatore.info/attachments/195_FT840_serv.pdf


I'm not sure why your actual VFO control has loosened requiring you to tighten the shaft unless it became loose due to the VFO knob becoming detached? If it's a 'wobbly' shaft then you may have more problems to hand than first thought with the actual VFO encoder being at fault.

I know with my Yaesu FT757gx I had a hell of an issue due to the actual encoder shaft assembly becoming loose due to age making tuning impossible. Due to the fact that a replacement control was as rare as hen's teeth I had to utilise all my ingenuity in rebuilding it which took some doing and was akin to delicate surgery(!)

I hope that yours is a simple fix and I'll have my fingers crossed that there are no encoder problems.


All the best,
Victor

thanks victor im going to have a proper look when i get home later today or tomorrow will keep you all updated 
dave

No worries Dave and I'll keep my fingers crossed that it will be an easy fix.  

73, 
Victor

just had a look at the 840 and it likes like I'm going to have to try and find an encoder as the wont turn it is just stuck solid how easy are these to try and repair? lucky enough though i can still use the radio due to up/down buttons on the mike
regards
dave

Hi Dave,

If it's of any help there's a video of a guy stripping his encoder on an FT840 here :-

https://www.youtube.com/watch?v=kBQhrEdW1f0


I've seen all sorts of repair ideas from the typical "Give it a squirt with WD mate" (not really advisable) all the way to tentative rewiring of a different type encoder.

I'll keep my fingers crossed that you get sorted out.

(I remember what a pain it was to use the 'band' & 'up/down' buttons when my FT757 VFO encoder failed!)


All the best,
Victor

thanks victor i have a go at next week it looks pretty simple i bet getting that shaft out is a real pain. and yes it is a pain using the buttons on the mike

No worries Dave and I wish you the very best of luck. 

There's nothing worse than having the radio itch but no proper working radio to scratch it!

(Just realised I must have crossed more fingers for you than I have available and sound like a demented parrot in my responses to you. )


73's to you mate.

if you like the hobby you want everything to work as should. the reason behind me having a go is I'm not going to be any worst of if i cant do has it is already broken. i have found a second hand encoder on eBay for £67.00 and £34.00 postage from the states, so i can do it i will save cost a ton and , if someone else has the same i can help them, as always thanks for your help
regards
dave

got the encoder off shaft is jammed solid taking shaft to moms as a friend has a vice where i can put it in and gently hot it with a hammer hoping that will free he shaft so i can clean it and make the vfo work again 
regards
dave

Glad to hear you're getting somewhere with it all Dave. Gently, gently with that hammer.

yes i know because the shaft is only made from soft metal and i dont want to bend it or break it, i might soak it in 3 in1 oil over night to help it loosen is that a good idea or not
dave

Sounds like a cracking idea, that or maybe meths/white spirit.

only goy 3 in1 wd40 here. just read your thread about power packs i got the you took a picture of and it ran my 840 on full power without any problems so i would say buy it
dave

good morning, victor i now have the shaft only had to it about 10 times and it came free then spend the next half hour looking for it on the shed floor new going out later to buy some emery cloth to give it a good clean so the shaft will spin again
dave

I have got emery cloth to clean it and yes it now spins as it should all I have to do so put altogether and see if I've repaired will found out when I get home

Good to hear there Dave and I must commend you for giving it all a go in the first place.

Sounds like you're coming along nicely with it all and look forward to your final outcome.

vof working as should thanks victor for your support and encouragement
regards
dave

Very well done there Dave and congratulations!  

I'm smiling from ear to ear to hear that you've fixed it and I'll bet you're well chuffed.

(Most would've bunged it on the bay with a "sold as seen"!)

That radio is most definitely 'yours' now after fixing it yourself. Awesome stuff.


All the best to you,
Victor

im not saying it was easy but take your time ,think about very step and im sure anyone could have done it.  i feel great so happy im now a rig doter lol not really