Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Matching Output Xformer to Spkr
#1

I've never seen this addressed before but when calculating the voice coil impedance in order to find a matching output xformer, don't you need to also include the hum bucker coil impedance in series with the voice coil? I recently dismantled a speaker and the hum bucker was separate on the pole piece. It had a decent amount of wire in that coil, surely enough to affect the overall impedance! Thanks

Ron

Bendix 0626.      RCA 8BX5.   RCA T64
Philco 41-250.    Philco49-500
GE 201.             Philco 39-25
Motorola 61X13. Philco 46-42        Crosley 52TQ
Philco 37-116.    Philco 70
AK 35                Philco 46-350
Philco 620B.       Zenith Transoceanic B-600
Philco 60B.         Majestic 50
Philco 52-944.    AK 84
#2

Well...yes you do. However I think compared to the voice coil the humbucker which is a much thicker wire coil shouldn't amount to too large a percentage. In addition the voice coil impedance is larger than its mere DC resistance as there will be the inductive component.
Plus when you replace the transformer it will likely be a good enough match, not an exact one.

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.
#3

Thanks Mike. I've seen some speakers listed with impedances of an ohm or two. The hum bucker coil I saw had a fair amount of windings so I'm thinking it would account for a fair amount of the total including voice coil.

Ron

Bendix 0626.      RCA 8BX5.   RCA T64
Philco 41-250.    Philco49-500
GE 201.             Philco 39-25
Motorola 61X13. Philco 46-42        Crosley 52TQ
Philco 37-116.    Philco 70
AK 35                Philco 46-350
Philco 620B.       Zenith Transoceanic B-600
Philco 60B.         Majestic 50
Philco 52-944.    AK 84
#4

Better yet, early Philco speakers are fractions of Ohm.

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.




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco 60 Squealing
I have recapped and replaced out of tolerance resistors and so on. Radio plays nicely on fairly strong stations. The pro...dconant — 10:55 AM
Philco 46-420 Code 121 Reception issues
Welcome Eric, I agree with Bob and far as the two main electrolytic filter capacitors did you change them yourself or w...radiorich — 11:43 PM
Philco 46-420 Code 121 Reception issues
You mentioned the Philco manual and going through the check points...just to be sure we're on the same page here's the m...klondike98 — 08:13 PM
Philco 42-1008 conversion kit
Interesting. I haven't seen that before.klondike98 — 07:02 PM
12' Philco
Yes I had looked for it on the web as well some time back and could not find it. I was glad to see it turned up in Ron'...klondike98 — 06:59 PM
Shadow Meter Bulb
Now if you had a set with a tuning light then the bulb type is important to the circuit, some sets used those prior to t...Arran — 04:58 PM
Shadow Meter Bulb
Ok. Thanks for the correction.RossH — 03:09 PM
Model 28L
For 28 you will probably need to buy a Hammond 125CSE. Or any of the series of the power you need, with SE suffix. Then ...morzh — 02:09 PM
37-60 revision 6
I am restoring a Philco 37-60 and it shows run 6 they removed the ground from G3 of the 6K7G and put the G3 to -2.5v for...bobbyd1200 — 01:01 PM
Shadow Meter Bulb
Mike is correct on the bulb connection, two separate circuits. I found that by rotating the bulb and sliding it forward ...RodB — 12:19 PM

[-]
Who's Online
There are currently 4712 online users. [Complete List]
» 3 Member(s) | 4709 Guest(s)
AvatarAvatarAvatar

>