deskthority

I can't post pictures on here to show this, but I've just noticed the keycaps on this 1984 UK Model F XT are thinner than all the others I've encountered - and I've owned about 8 now. The walls are slightly thinner and they lack the little "posts" in the corners. They sound less dense when handling them. Interestingly, this XT sounds noticeably deeper than my pristine US one. Doesn't sound as crisp or entertaining though, but this is probably due to the condition of the foam - the centre row sounds dead. All three UK Model F XTs I've owned had bad foam (the type with the white skin on one side), whereas the US ones have always had intact foam.

Here's a sound test: https://youtu.be/xpf_BtBMkJ8

I have not yet experienced this myself but without seeing a picture of the UK key cap next to a US one I can't really see for myself the difference.

I have found though that one of my UK made IBM Model F XT keyboards does have a different sound and feel than my US made IBM Model F XT not sure why though.

While there are quite a few differences to tell an UK and US made XT keyboard apart - including the shape of the keycaps (US made ones usually having slightly rounder corners than UK made ones), the thickness is not such a clear indication and seems to vary quite a bit.
I would say my experience leans actually more to the opposite - concerning thickness.
for example: left: UK / right: US

AJM wrote: ↑

04 Apr 2019, 22:01

While there are quite a few differences to tell an UK and US made XT keyboard apart - including the shape of the keycaps (US made ones usually having slightly rounder corners than UK made ones), the thickness is not such a clear indication and seems to vary quite a bit.
I would say my experience leans actually more to the opposite - concerning thickness.
for example: left: UK / right: US
e1.jpg

I'd definitely agree with you with the US keycaps feeling "rounder". My UK model has quite sharp keycaps. The legends are also razor sharp, they're the best dyesub legends I've ever seen, for sure. What's the reason for these differences?

I put the keycaps back on after cleaning, and now the key feel is spongy and the click is weak. Fantastic. I know the foam is in awful condition, but I don't see the point in opening it and making a new foam mat, when it has never ever worked out well. I've ruined Models F by opening them and replacing the foam... I just can't get it right, no matter what I use. I've tried automotive headliner, neoprene (1mm, 2mm, 3mm - none of it particularly spongy as it's hard to source soft foam here in the UK) and art foam. I'd love to give the stuff Fohat recommends a try, but of course, I can't get that brand here.

Hi as i said in my IBM Model F AT ISO Layout mode post I too am in the UK and do use 3mm neoprene foam that I get from eBay for a good price and works very well with both my IBM Model F AT And both my IBM Model F UK keyboard and my US XT Model F.

oh and a side note for all my IBM Model F restorations I do full deep cleaning not just key caps and case. I clean the barrel plates, barrels and I have always had good results basically the keyboard pretty much feeling like new.

Fkazim wrote: ↑

05 Apr 2019, 15:31

Hi as i said in my IBM Model F AT ISO Layout mode post I too am in the UK and do use 3mm neoprene foam that I get from eBay for a good price and works very well with both my IBM Model F AT And both my IBM Model F UK keyboard and my US XT Model F.

oh and a side note for all my IBM Model F restorations I do full deep cleaning not just key caps and case. I clean the barrel plates, barrels and I have always had good results basically the keyboard pretty much feeling like new.

Could you link the product you use? Do you have a sound test of the assembled keyboard? I find the spacebar never sounds as good, and the center row of keys sound/feel spongy.

The link for the foam I use is here: https://www.ebay.co.uk/itm/BLACK-NEOPRE ... Aysqd0xZlA

I will post a sound test tonight focusing on the keys you have mentioned hope that helps.

Fkazim wrote: ↑

08 Apr 2019, 12:16

The link for the foam I use is here: https://www.ebay.co.uk/itm/BLACK-NEOPRE ... Aysqd0xZlA

I will post a sound test tonight focusing on the keys you have mentioned hope that helps.

Thanks for your reply. I bought black 3mm neoprene from another seller last year, which was from a different seller, but had an almost identical title to what you linked. It was far too stiff and firm, making reassembly impossible.

Yes it will seem impossible but use lots of clamps and it will work a treat.

Fkazim wrote: ↑

08 Apr 2019, 22:15

Yes it will seem impossible but use lots of clamps and it will work a treat.

I was. I was using plenty right near the tabs - still not even close. This was with the thick 3mm stuff. Is the stuff you used fairly firm as well? I'd like to hear how it sounds if you have recorded a sound test yet.

It's kind of medium firm but not hugely firm will send the sound clip of the keyboard in a few mins.

Here is how my IBM Model F AT sounds with new foam: https://www.youtube.com/watch?v=pWQYwflpbbs

Fkazim wrote: ↑

08 Apr 2019, 22:51

Here is how my IBM Model F AT sound with new foam: https://www.youtube.com/watch?v=pWQYwflpbbs

That just isn't fair. D: How come your foam actually works for you? Hmm... maybe it's just my technique. I was using lots of spring clamps, but no bar clamp. I would just hammer the backplate into place. It's possible that I was bending the metal slightly and upsetting the tension. Either that, or the foam material I am using is not good. It's probably because my mats suck.

I've got a big wooden block now, so I can use it to apply even force when I hammer the plates into place with my next foam replacement. I'm tempted to buy that stuff you linked, just to see if it's any different to what I bought a year ago. I have a few XTs that need to be refurbished. I think I will try the 1.5mm jiffy packing foam first.

Shame about the spacebar sound. The AT I am typing on right now also has that same shallow, rattly spacebar sound. I've heard some that are really deep and thocky. I wish you could mod them to sound like that. I wonder what causes such dramatic changes in sound, despite the fact it's the same model.

Anyway, thanks for uploading that.

Hi just to answer some of your questions I clamped my keyboard plate down absolutely everywhere there was a locking tab. the space bar sounding rattly mainly occurs when you bend the stabiliser outwards to lighten the space bar this has been done to mine. by default the stabiliser is putting a lot of tension on the space bar this is why the space bar is insanely heavy to press by default. So when you bend the stabiliser outward to lighten the key feel you in tern decrease the tension meaning the stabiliser now has space to jump around in the stabiliser clips on the space bar this is what I think creates the rattly sound hope that helps. Also I recommend when you do your next foam replacement to clean everything including the individual key barrels I know this might sound tedious and it is but it will be well worth it in the end in terms of key feel trust me.

Hope that answers your questions

Fkazim wrote: ↑

09 Apr 2019, 00:24

Hi just to answer some of your questions I clamped my keyboard plate down absolutely everywhere there was a locking tab. the space bar sounding rattly mainly occurs when you bend the stabiliser outwards to lighten the space bar this has been done to mine. by default the stabiliser is putting a lot of tension on the space bar this is why the space bar is insanely heavy to press by default. So when you bend the stabiliser outward to lighten the key feel you in tern decrease the tension meaning the stabiliser now has space to jump around in the stabiliser clips on the space bar this is what I think creates the rattly sound hope that helps. Also I recommend when you do your next foam replacement to clean everything including the individual key barrels I know this might sound tedious and it is but it will be well worth it in the end in terms of key feel trust me.

Hope that answers your questions

Thanks for the detailed reply.

I've never had issues with scratchy switches in a model F, and I've owned about 8 or 9 XTs alone. I do clean barrels when I disassemble the keyboards, but it's not a priority when the assembly does not need to be opened.

This spacebar definitely has not been lightened, but I don't mind it that way. I doubt that's the cause for the rattle, although it might be in your case. Every Model F I've owned sounded different to the last, when there is no logical reason for it. The pitch of the ping, the clickiness, the thockiness... they all have different-sounding spacebars.

I think if I ever open this AT, which I probably will do when I can paint the barrel frame, I will grease the spacebar stabiliser. I might even add a bit of foam where it makes contact with the plastic, just to mute the sharp sound it makes.

Adding foam on the space bar makes sense and may be something I would try if the noise starts to annoy me too much. Sad part is my space bar did not sound at all hollow/rattly to begin with all the rattle started when i lightened the space bar. Still fair trade off as I could never deal with the default heavy space bar.