capacitor question

sda2mike

i have some old marantz speakers i'm going to redo the xover's on...the 1 cap is listed as: 7mf 100volt...what value in uf would i use? thanks mike

[Deleted User]

Hello,
That would be 7uF.
Regards, Ken

ShinAce

I would think it is 7uF, 100V.

Can you take a picture of it along side a coin or ruler?

Is it marked with a - sign anywhere?

[Deleted User]

ShinAce is correct, I had to recheck what I thought was right.
Ken

sda2mike

thanks guys...i was thinking it was 7uf, just wanted to be sure...i haven't extracted it yet, so no pics...it looks soaked. so i dont think it'll be readable..damn things sound great, btw!

ShinAce

sda2mike wrote: »

thanks guys...i was thinking it was 7uf, just wanted to be sure...i haven't extracted it yet, so no pics...it looks soaked. so i dont think it'll be readable..damn things sound great, btw!

I was just hoping to cover my bases. But I've seen you posting long enough to guess that you'll choose a high quality replacement cap.

Based on the value, and the fact that it's a crossover cap, I believe it is in the tweeter's signal path.

[Deleted User]

Initially I was reading it as "mmf" which is not used much anymore.

ShinAce

Kenneth Swauger wrote: »

Initially I was reading it as "mmf" which is not used much anymore.

And what happened to j? I remember caps like '102j' and stuff like that! That would have been 10 * 100 pF, or 1nF.

p.s. I'm 27, so the parts were about twice my age.

Face

Ace, I still see that system used on very small values.

sda2mike

ShinAce wrote: »

I was just hoping to cover my bases. But I've seen you posting long enough to guess that you'll choose a high quality replacement cap.

Based on the value, and the fact that it's a crossover cap, I believe it is in the tweeter's signal path.

hey shin...yeah it looks like it's in the tweeter circuitry...thanks for the vote of confidence! probably dayton's for these! marantz imperial 6..made between 71-75..they deserve a sprucing up

thanks
mike

ShinAce

sda2mike wrote: »

probably dayton's for these!

Rock on!

[Deleted User]

I have a 1940s era Amateur Radio Handbook that I have to look up some of the older nomenclature when I get stuck. It's also a great handbook for DIY construction techniques. In those days ham guys had to build just about everything they needed. Probably still do.

[Deleted User]

Hey Xcapri79,
Oh yes, I still use a Griefkit (Heathkit) alarm clock that must be 40 years old. I built lots of those kits, they had a store not far from where I lived and haunted it quite a bit. I built just about every piece of test gear they made, generators, 'scopes, VTVM. I didn't have much money so each kit was saved for. I still look for NIB kits on eBay.
A friend of mine who has the best set of audio "ears" I know of is very big into amateur radio. He claimed getting interested in it probably kept him out of reform school. A next door neighbor took an interest in him when he was a kid and got him started. He won some long distance DXing competitions a few years ago. He says that trying to listen through all the noise and static on the air trained his hearing. He used to tune Decca cartridges by ear getting channel separation and tracking distortion perfectly. His modified Dynaco ST70 and PAS3 were great decades before anyone else started doing them. His and the Paoli were the first ones.
Ken

skrol

Ken
Was that the store on Jappa Rd? I used to help my dad build some of those kits. The most memorable was the TV kit that he was able to buy through the GI bill. You had to build all the test equipment that you were going to use to build and tune the TV including a breadboard with power supply and function generator, DMM, and an o-scope. I had the scope until it died a few years ago.
Stan

[Deleted User]

Hey Stan,
Yes, that's the one. I think it's Easter Lock and Key now, CD Depot is right around the corner. I still have the separate tuner with the key panel, you push 99.1 and it goes right to the station. There is a drop down door that holds three pre-set station frequencies. I did a lot of modifications on it, all new parts in the audio section. I even made my own balun transformers trying to perfectly match the antenna to the front end. I learned how to solder with their kits. The variable temperature soldering station was really cool. You did all of the manual construction including wiring and then used it to solder itself together. Making a TV was the ultimate, I don't think I was up to that level. That's great that your Dad built one, very cool!
Cheers, Ken

MillerLiteScott

Baynesville Electronics on Joppa Road. It is still there. I drive by it almost everyday. I go in their every once in a while to get this or that but it is pricey compared to the internet. They still have some simple Velleman kits. I do not think they have tubes anymore but they have a cool collection of old tube radios on display.

The owners license plate is Ohmslaw.

Scott

[Deleted User]

Sure, I go into Baynesville for lots of odds and ends that I need. It's got to be one of the last electronics parts stores in Baltimore. I try and use them whenever I can so they stay in business. They used to sell tubes, blank open reel tape all kinds of things. Up until a few years ago they used to hand write a sales receipt. Every time I walk into the place I think, "How much longer will they be here?" But there's always customers looking for a certain cable or battery, so I guess they're doing okay. I hope so.
Ken

skrol

I used to go there all the time with my dad who is a long time analog and RF guy. Now I only get up that way for my eye doc appointments in Towson every 6 months. I usually stop in Baynesville after. There is always something that I need. The only problem is that I can't read any part values with my eyes dilated. Then I get to thinking about my dad and have to blow off a couple more hours of work to pay him a visit.