04-16-2018, 01:21 PM
Thank you Mike!
Philco 37-610 tombstone restoration
04-16-2018, 01:21 PM
Thank you Mike!
04-16-2018, 01:26 PM
Whoops, wrong 610 discussion. Sorry about that.
04-16-2018, 03:11 PM
To answer morzh first was checked in connected but after I desoldered sides to check again only few get into values, the rest were out or leaking like 30% or above... That is the reason I asked here, I do not know if is relationed but one of the resistor of 47ohm was like 70Mohm... Other resistors were ok. Maybe they got damage by connecting to power line at some point without repair?
04-16-2018, 03:27 PM
To answer, first: the caps should almost always be checked out of circuit. Which could just mean one lead desoldered.
Now, by ceramic you are likely meaning the mica molded caps (I have to go and look again into my chassis on the bench). Those are extremely stable, almost never are off by much. It is very strange that you have many of them off. So, 1. Are you measuring with hands NOT touching the leads (only the meter's leads should touch the caps' leads, hands should only touch the plastic holding part of te leads)? 2. How much heat did you have to apply to desolder the caps? Too much heat could damage them. 3. How quickly after you had desoldered them did you measure the caps? You should let them cool off - the heat does affect the reading. 4. You are MUCH better off not even touching mica caps. They are almost never in the places that present the danger of damaging the power supply. In a rare case they are bad, you will quickly find out about it. I never touch them. Never have met a bad one so far. People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
04-16-2018, 04:27 PM
Hi morzh, I checked them out of the circuit, desoldering heat was I think normal since inmediatly after melting I remove the leads, in this SG is better cause all caps have very long leads, so less heat reach the core (I can touch the component and is barely warm) measurement is done with crocodiles and not touching the components/leads, in this SG there are only ceramic, one double electrolityc and two micamold tropical, this last two only one was ok in value but leaking too 25% (out circuit) for me is strange since I have repaired more modern things and never found a ceramic so leaky/out of 20%tolerance.
04-29-2018, 02:27 PM
Well after repair the SG (change of all out of value ceramic, electrolytics and micamold) the heathkit works good, I checked calibration and is good now, only 10% difference with a digital meter, I made the alignment and now the radio get the stations with accuracy and more volume, although still if I touch control grid of 6A8G I get better volume, also I found that compensator #4 was very loose and did nothing adjusting it to the output, the rest were ok.
04-29-2018, 04:00 PM
The phenolic dial was little blurry and some printed areas gone but will leave it since is not too bad
04-29-2018, 04:05 PM
Now just install of the grommet bushings for the chassis and finish the cabinet, I used some NOS "g" tubes that I found very cheap here in Spain, the rectifier in g version gets very warm, I supose bigger means more heat
04-29-2018, 04:08 PM
By the way I forgot to tell that the speaker sounds great with no distorsion, I though changing the cone with a rigid one will make something bad or my skill (first time recone) too but I am very happy with the sound, if anyone want to know the italian seller of the cones just ask me.
04-29-2018, 04:17 PM
Looks real good. Can you put up a picture of the speaker?
05-01-2018, 10:03 AM
Hi KCMike, in the previous page in posts #68, 69 and 72 you have pictures of it, if you need a closer one or a detail just tell me and I'll do it.
05-01-2018, 10:18 AM
Thanks Jeepeto. I must have not been logged in when I read the posts and did not see the speaker pics.
I was curious about the cone you used. It looks like it fit very well in regards to the depth/angle to the voice coil and did not have the foam around the outer edge that I've ran into here.
05-01-2018, 06:11 PM
You are welcome KCMike, yes the cone fits almost like original, just trim with scissors the outer diameter (is 8") the angle is a bit deeper, so I had to cut a spacer from hard cardboard about 2mm thick to raise the cone that bit to rest the hole underneath the spider, sounds very well and move freely.
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