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:
[-]
Recent Posts
Philco model 38 code 121 not receiving signal.
Thank you sir. Yes I feel good and also relieved because this one's been weighing on me a bit.Stormlord5500 — 11:18 AM
Philco model 38 code 121 not receiving signal.
It feels good don't it? Good luck on the rest.Paul Philco322 — 11:06 AM
Philco model 38 code 121 not receiving signal.
I've reinstalled the coil. Now IT'S ALIVE!!!!!! I fired up my TinySA on signal generator mode and set it to 1400Kc and ...Stormlord5500 — 11:01 AM
Philco model 38 code 121 not receiving signal.
Yes, Walmart, right up there with Fluke.RodB — 11:00 AM
PT 6 chassis screws size???
it certainly won't be metric! SAE threads were all that was known then. Take care, - GaryGarySP — 10:58 AM
Philco model 38 code 121 not receiving signal.
I think this thing is way more accurate than my Walmart DMM. :DStormlord5500 — 08:19 AM
Philco model 38 code 121 not receiving signal.
Thankyou for the kind words sir. I double checked it with my component tester and it read 2.7 ohms at .02mH.Stormlord5500 — 08:14 AM
PT 6 chassis screws size???
Hello bridKarl, that sounds right or maybe 8/32 . Sincerely Richardradiorich — 01:00 AM
PT 6 chassis screws size???
Have this done except for missing chassis screws. It looks like 1 inch 6/32 sheet metal screw may work but can anyone s...bridkarl — 10:32 PM
Philco model 38 code 121 not receiving signal.
Hello Stormlord, Well done on rewinding that coil it turned fairly good for your first one. Sincerely Richardradiorich — 09:12 PM

[-]
Who's Online
There are currently 873 online users. [Complete List]
» 1 Member(s) | 872 Guest(s)
Avatar

>