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

Vol control with tap
#1

Hello All.
I have a Firestone Model R-1661,
http://www.nostalgiaair.org/pagesbymodel...006273.pdf

The radio plays after restoration with the exception of the volume control ( #41A 250k ohm) which has some bad spots in it and I would like to replace it but the control has a Tap. Also the value of the pot is 500k so someone must have replaced it at one time.
Can I omit the tap?
Is there anyway to know the value of the tap or is it standard?
Is there a workaround I have a 250k pot I can use but it does not have a tap. 

Thanks Eric
#2

Eric
The tap on the vol pot is for slight equalization of the audio at low volume.  It rolls off the high frequencies a little at low volume.

On the old stereo receivers it could be switch in or out. It was called "loudness contour". 

Using a volume pot without it if you don't like the sound you could add a cap of similar value at the high side  and change it's value to suit your tastes. You may not even notice any difference unless you are listening for it.

!!!!!!!!!!!!!!!!!!!RESISTANCE IS FUTILE!!!!!!!!!!!!!!!!!!!!!!  
                           /\/\/\/\/\/\/\/\/\
                                                     
                                 [Image: http://philcoradio.com/phorum/images/smi...on_eek.gif]  Chris
#3

Hello Eric,
I would Give Mark at https://www.oldradioparts.net/
He repairs controls he has lots of them .

Sincerely rich
#4

My late father in laws Zenith with a tap on the volume control that had been replaced in the past. After a recap and a few resistors replaced the radio played fine. The repair shop placed10 turns of wire from what would be the the tap feed around the in coming signal to the control. The repair was made in the time frame of 1968-1975.
#5

So I played around with it and put in a 250k pot I had and left the tap lead off and it played fine but I also needed a switch for power so I looked in my box of stuff and came up 500k w/switch and put that in just to see what would happen and it actually played better than with the 250k pot.

 I have bought from Mark Oppat before but I also don't know the value of the tap. Is standard value?

Thanks 
Eric
#6

Hello eric,
Sure thing .

Sincerely Rich




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Correct model 84 Ac plug an cord type
I remember a bakelite "lampshade" (a fancy lampshade) style plug being available in the hardware store when I ...MrFixr55 — 10:39 AM
Correct model 84 Ac plug an cord type
Hello Arran Yes, I also like the lampshade style plug ! Sincerely Richardradiorich — 08:46 AM
Restoring Philco 38-14
Hello morzh, Nice explanation on the x and y capacitors and glad you are narrowing down the issue with this set ! Si...radiorich — 08:43 AM
Correct model 84 Ac plug an cord type
From what I read Philco went to using brown rubber power cords in 1936, so cloth was used in the 1935 and earlier models...Arran — 11:25 PM
Correct model 84 Ac plug an cord type
Hi Bruce, I have not worked on an 84, but in general, power cords for almost any radio prior to 1938 was cloth covered...MrFixr55 — 08:34 PM
Restoring Philco 38-14
OK, well, so after staring at the sch again, I realized the problem had to be the #12/12A padder. I put a scope on the o...morzh — 08:15 PM
Correct model 84 Ac plug an cord type
Hello Bruce, I mostly use brown far as my cloth powercords go ! Here is the plug that I have used bakelite Acorn style...radiorich — 08:05 PM
Correct model 84 Ac plug an cord type
Looking for as correct as can find the right Ac plug an the correct colored cloth line. Ive seen many old photos but mos...Bruce — 04:13 PM
Restoring Philco 38-14
Rod Two Y-caps make sense if you use them from L/N to the chassis; this is only makes sense in the transformer radios w...morzh — 10:11 AM
Restoring Philco 38-14
Mike, I'm curious about a specific use of he Y cap. Lately I've seen a single cap across the power transformer primary. ...RodB — 09:01 AM

[-]
Who's Online
There are currently 3719 online users. [Complete List]
» 1 Member(s) | 3718 Guest(s)
Avatar

>