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73 cast frame 122142

Posted: Sat Jul 11, 2009 1:54 am
by xtoby44x
so I'm new here and a HIWATT noob as well just got a 74 DR-103 with matching 4 X 12 cab with 3 original cast frame 122142 dated 24/73 and two replacement fane medusas to be arriving this monday. one of the originals is supposed to be on it's last legs according to a tech that looked at the cab and stated the speaker is working and the cone is good but the voice coil needs to be replaced and is showing low output. got the original speaker today and the cone does look really good. so what are my options? how much is an average repair on a voice coil price wise? who or were should i send it to to get repaired? I am based in Long Island New York and if anyone has a matching original to complete this cab that they would want to part with please let me know.

thank you in advance for the help, and i really have enjoyed this forum and the knowledge i have gained from here already in my short time here as a new member.

Re: 73 cast frame 122142

Posted: Sat Jul 11, 2009 2:17 am
by mikhailwatt
From what I've been told (by those who should know), replacing the voice coil means replacing the cone as well. :cry:

Re: 73 cast frame 122142

Posted: Sat Jul 11, 2009 2:24 am
by xtoby44x
really I was kinda afraid of that and thank you.

Re: 73 cast frame 122142

Posted: Sat Jul 11, 2009 3:14 am
by OldSchoolDave
xtoby44x wrote:one of the originals is supposed to be on it's last legs according to a tech that looked at the cab and stated the speaker is working and the cone is good but the voice coil needs to be replaced and is showing low output. got the original speaker today and the cone does look really good.
First thing I'd do is get a second opinion...

If the speaker sounds good but merely has lower output than the others, find a different application for it. Try two Medusas with two original Hiwatt Fanes in your 4x12 (assuming their impedences are the same). I haven't tried that combination, but who knows?

Sometimes, gunk buildup in the gap can cause voicecoil rub. The good Dr.Hiwatt documented a procedure that can resolve that in certain cases.

I view reconing strictly as a last resort. Exhaust all other options first. Reconing a vintage Fane can change its character (since original kits are non-existant). Not to mention, it's hard to find someone who is equipped to do the job.

Fire up those speakers and let us know what you find out.

Dave

Re: 73 cast frame 122142

Posted: Sat Jul 11, 2009 4:10 am
by xtoby44x
Thanks Dave,

will do exactly that on Monday when it gets here and post pics and results. I really would like to get it in as it was purchased new in 74 condition but as I'm reading around here that can be a difficult task to accomplish.

Bill Z

Re: 73 cast frame 122142

Posted: Wed Jul 15, 2009 6:17 pm
by jcmh1
Dr.Hiwatt documented a procedure that can resolve that in certain cases.
Dave ... any idea on where this can be found ?

I have one that i bought about a year ago that was rubbing and managed to make it right in the end. But, it was a real bugger to get the 4 bolts out that hold the magnet to the rest of the frame ... then a little shimming did the trick (used tin foil)

thanks .. john

Re: 73 cast frame 122142

Posted: Wed Jul 15, 2009 7:51 pm
by Dr.HI-TONE

Re: 73 cast frame 122142

Posted: Wed Jul 15, 2009 10:45 pm
by jcmh1
viewtopic.php?f=5&t=22
DH ... thanks for the pointer ... your method was different than what I did and obviously works too. Since I took the whole thing apart I didn't have to cut the coil cone off. Doing it my way, you can also see what sort of shape the voice coil is in (not saying my way is better, just that's what I did). In my case, there was a bit of wear, but it had not gone through the varnish on the copper coil. Just in case, I added a very thin layer of varnish on it. I shimmed between the magnet and the rest of the frame. I put some shim in on the low side, tightened a little, manually moved the cone and listened carefully for rubbing, and adjusted or repeated until the 4 bolts were tight and no more rub. It was surprising how little shim was needed. It did take a while, and a few false positives.

In case anyone is wondering, this was a 1971 cast Fane, 122231 It took several days of carefully applying small amounts of "liquid wrench" to the bolts to get them ready to come off. The bolts were REALLY tight, and I didn't want to break one off. There was no way I was going to put any heat on them.

... another entry for the Hiwatt Handbook .... someday

john

Re: 73 cast frame 122142

Posted: Wed Jul 15, 2009 11:12 pm
by Dr.HI-TONE
Perhaps, I didn't mention it or it was another speaker all together (I've slept since then :lol: ), I have taken the frame/basket completely off and inspected the voice coils as well.

Re: 73 cast frame 122142

Posted: Wed Jul 15, 2009 11:33 pm
by jcmh1
slept since then
Don't forget that ... very important when it comes to the fine motor moments of patching things up

john