Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

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

VTVM Necessary?
#1

I have several Philcos and Zenith radios that are in need of alignment. No problem with the AM but some have FM and I'm wondering if I need a VTVM for that purpose as most instructions say to use either that or an oscilloscope. All I have is a signal generator, an analogue DVM and a Fluke DMM.
#2

A VTVM or FET voltmeter is highly desirable for alignment.You adjust a trimmer or inductance to get a peak response. This is easier with a VTVM or FET meter because the meter response is quickly observed after an adjustment and you observe when the needle reverses indicating the peak has been passed.With a DMM there is a longer settling time after adjustment and you have to remember the last reading to detect passing the peak rather than watching direction change of the needle. I have no experience with an analog DVM.
#3

After looking at several I found one by EICO, a model 249, that I bought. I remember using a Simpson and Triplett many moons ago but never a VTVM. Another piece of equipment added to my repertoires.
#4

Eico made good instruments. I use 950 bridge and a 147 sig tracer. Good choice.
#5

I recently picked up an HP 8656B Signal generator and an Elenco 9500. I should be good to go.Icon_smile
#6

VTVM nice to have. Digital meters can drive you nuts when trying to peak alignments. Old Funcional Heathkit or Eico fine for this. Just wanting to get peaks, absolute accuracy not relevant if you catch my drift.
#7

"Digital meters can drive you nuts when trying to peak alignments."

Not "can" but WILL drive you nuts, when trying to peak alignments! Icon_crazy

-Greg




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Need Help to ID this radio 11 tube Philco
Yes the 16B as morzh pointed out. Specifically its the January 1935 model version of the 16B. There are a couple earli...klondike98 — 11:51 PM
48-482 rear panel help
Welcome to the Phorum, keithchip! How far you take a radio on cabinet restoration is a matter of personal preference. ...GarySP — 11:28 PM
48-482 rear panel help
I've recently finished the internal restoration of a locally purchased Philco 48-482. The cabinet is in ok shape except ...keithchip — 10:28 PM
Need Help to ID this radio 11 tube Philco
Welcome to the Phorum, Ken! Lots of help here for all of your restoration questions. Take care and BE HEALTHY! - Gar...GarySP — 07:59 PM
Need Help to ID this radio 11 tube Philco
Thank you. I went to your online library and found 2 schematics. I will download and compare to components!Ken D. — 06:31 PM
Need Help to ID this radio 11 tube Philco
It is a 16B tombstone.morzh — 06:13 PM
Zenith H725
David - sorry, I reread your post and finally saw THD - now the % figures make sense. Thanks for explaining. The PSU...EdHolland — 06:06 PM
Need Help to ID this radio 11 tube Philco
Hi Everyone, New member but have been reading this for awhile for tips! Vaccum tubes were before my time so bear with ...Ken D. — 06:03 PM
My Philco 37-116 Restore
Thank you MrFixR55, I appreciate your comments very much. I do not detect much hum if any so I will be staying with the ...dconant — 05:15 PM
My Philco 37-116 Restore
Hi DConant Yes, you can replace chokes with resistors.  You do stand the risk of increased hum.  the solution is to inc...MrFixr55 — 04:23 PM

[-]
Who's Online
There are currently no members online.

>