Farnsworth Discussion

I'm assuming that the speakers are of the same impedance (like 8 ohms or 4 ohms whatever the original was).

Yes it is an 8ohm just like the other.

I can see from the pics that you've used fairly thich solid wire to connect to the speaker. Just how hot was the soldering iron and how long did you hold it on the speaker terminals when soldering? It's one of those jobs that needs to be done as quickly as possible. It looks like you might have heated up the voice coil to point where the adhesive has let go. You've also got a lot of bare wire exposed on those speaker leads.

not sure on the temp as it does not have a selective temp. The speaker came with soldering already on the leads it held it on them long enough so the wire end could attach itself and re solidify, which was very quickly. So I'd have to re heat it, maybe that when its happening with the thicker wire.

I'm
Pare only as much insulation as you need to connect it. First tin both the speaker terminals and the bared copper wire ends with a little solder. Then place the two tinned surfaces together and apply heat long enough to get the solder to flow. Remember that thick wires and different metals will act more as a heatsink than others and need more heat. It really pays to practice on something a bit to get used to how hot the iron needs to be for the components and the type of solder and how long you need to apply the heat for. If you can adjust the temperature of your iron even better. It needs to be just hot enough to melt the solder quickly. If you ever decide to try soldering transistors or ICs remember heat can be a killer.

So try the extra speaker if you have one left following those tips and see if it helps. Maybe practice on a bit of the perfboard I saw in the photo and try to solder some wires to it quickly.

ps. I can see from the photos that you've applied a lot of heat when soldering wires to the circuit board. Be really careful as you can lift the copper pads (connection areas) off the board with too much heat.

Yea luckily I have one more of those speakers left that I ordered I can try, But I'm told now RadioShack sells them (whew) so I don't have to order anymore. I didn't tin the end of the thicker wire so that also maybe why.

the heat marks could be from having to reattach the original wires back to those spots several times because of them breaking during when I was setting up. I thought of maybe just reordering the board, since I don't think I have any of the original type of wire and nowhere near me sells it. I could order a spoole of it, but I honestly don't need that much of it and I figure I can get a clean board also. I might play with what I have first, since the electronics is basically all I have left.

thx for the help.
 
ok I replaced all the wires back to the stranded type from before and bought the same speaker from radio shack with wires already pre-soldered. So far it seems to be holding together <cross fingers>. So with that fixed hopefully I can finish this today, after I let a touch up coat of paint dry.
 
On the QMx one the screw goes through a hole in the circuit board and into the "camera lens" which is extended at the back. They've cast all their own parts. To remove the faceplate you take out that screw (with supplied Allen key) and remove one of the knobs. One knob does nothing and is attached to the faceplate, and the other controls a timer via a pot on the circuit board.



Or a small rare earth magnet to the faceplate and one on a standoff in the case in each corner.



How do the knobs hold it in place? Are your pot and switch glued to bottom of the case? If they are only attached to the faceplate as mine are, the bottom of the faceplate will still move.

I think the little magnet approach is the best. I've not put the screw/rivet in the back of my box and doubt I will though the screen-used ones have something there.

Oh, yeah... I've got my switches secured. I just assumed that anyone building with electronics would do the same. Guess I forgot that old rule about assumptions :)

And thanks for the description of the QMx mechanism. Interesting. But I still think they were overthinking it.
 
Has anybody figured out the placement of the side jacks yet? I've read most of this thread and I'm almost done assembling mine, but I've been holding off drilling the holes until the last minute because I'd just be eyeing it. If anyone has actual measurements, I'd be much more confident.

OK I measured the QMx one and the centre of the first jack is 30mm above the bottom of the case. The second one is 12.5mm above the first (ie 12.5mm between centres). They don't have to be the same as a dual banana plug as that direction finder add-on fits into two extra holes with eyelets up near the top.
 
Pretty Much finished mine tonight enough to show.

Things left to do that are minor:

- Still need to properly secure the left and center switches, since they wiggle around when messed with. Still trying to figure out what to do for that.

- Right side of faceplate sits a little higher which I think is due to the battery pack placement.

- even with switching the speaker (again) and the wires back to a stranded type (again) the sound still gets softer and softer as it rings. I have no idea whats going on at this point. I'll try and take a video to show what the issue is.

otherwise I'm very happy with how it turned out, especially since this is the second prop I've made myself since joining this board in 2002!. a big THANK YOU to shawn (jedibugs) for answering ALOT of my questions on putting this thing together.
 

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I apologize I haven't looked through the thread very much but its just a quick question. Does anyone know what Lens to use/ how to get one and does anyone know of anyone still making the custom faceplates? Anyone know of a printout for the faceplate? Debating cutting and tracing with an exacto knife and pen before cutting into metal just to get the placement right. My goal is a non-functioning one and if it comes out well I may go more advanced for my next one.
Thanks,
 
As far as I know no one is currently making runs of faceplates. There is a drawing you can use to make the faceplate here in the thread. As far as a found lens that info is in the thread too. You can use 80mm watch glass (laboratory drying glass) or an old Ford radio dial glass ('36 or '37 from memory). Details should be here too.

0272239.jpg
 
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As far as I know no one is currently making runs of faceplates. There is a drawing you can use to make the faceplate here in the thread. As far as a found lens that info is in the thread too. You can use 80mm watch glass (laboratory drying glass) or an old Ford radio dial glass ('36 or '37 from memory). Details should be here too.

View attachment 232860

I used the ford radio glass on mine, painted it and just hot glued it to the back of my faceplate.
 
Tomorrow after work my wife is taking me up to the Queen Mary in Long Beach for the Haunted Queen Mary event. Going to hang out and tour the ship tomorrow, thinking of dressing up old style and trying furiously to get my farns complete to take pics with. Trying to work on my audio chip and noticed, I have the ring tone, but not the answer or end call ones and can't find them. Any help?
 
Years ago, when I found about the RPF, the Farnsworth discussion had been going strong for some time. Unfortunately, I only found out about it when selling faceplates became prohibited. Since W13 is coming to an end, and QMx sold all of its Farnsworths, is it still taboo to ask if anyone has an extra faceplate?

I hope nobody gets mad for asking this. It's just that I had found all of the parts necessary to build 2 Farnsworths (for son and nephew), but never had the chance of getting a faceplate. If anybody can help me out with this, I'd really appreciate it. It would certainly make 2 children happy.
(If anybody knows any shop that would make them in NJ, it would help as well).
 
I thought I read something in Project Runs about another possible run of the Farnsworth Brass Faceplates?

Brass Farnsworth Faceplates (Russrep)
ED
 
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So, I'm quite a bit late to the party, but have been slowly getting the parts together for this.

I bought an old Wheately box in black. Going to have to paint it. Have retro-fitted my old Galaxy Note 2 to fit into it and am looking for a glass lens that will fit nicely and distort video calls when they come in.

Just wanted to thank you guys for all the work you've done.
 
Hi Guys

I know I'm late to the party now we've seen the last episodes of the show, but I've been following this thread for years whilst developing my own 'tribute' working Farnsworth. O.K., not working as in communicating with other units, but it does play videos, has a remote control 'ringer' and is rechargeable from it's own charger or any USB source.

After many false starts, I've managed to cram in all the electronics, both 'home brewed' circuits and commercially available ones, and an LCD screen. I guess if a picture paints a thousand words, then I should post a video to show it off in action.


I look forward to your comments and questions. I'll do my best to help.
 
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WOW.. that simply amazing! Great work on the Farnsworth BeachcomberBob :thumbsup
Looks realy, realy cool... simply like the "real thing" congratulations :thumbsup
 
Many thanks Murdoc.

I suppose I should explain that the cable you see at the beginning of the video is only used for attaching to the universal 'Worldwide' mains charger, and the one in the packet at the end is the full USB data cable for use in case the embedded videos ever need replacing or changing. When plugged into a PC, it's simply seen as an external drive. I just didn't know when to stop :lol
 
Without access to a laser, I had to photo etch my brass in one go like a p.c.b., including all the holes and slots. Tip: To 'antique' it, try leaving kitchen paper towel, soaked in caustic soda solution, in haphazard clumps for a few minutes. (Make sure you rinse well after - and wear gloves!)

Brass Etch.jpg
 

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