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

Model 87 Tube Substitution?
#1

Newbie here with a model 87 lowboy.

My 280 tube is broken. Is there substitution tubes I can use? The 280 is pretty expensive.
#2

280 is a plain 80, later known as 5Z3. The globe shape of the older 280 is what drives the cost up so high.

GL
#3

Thanks Exray! I still have a lot to learn, but I'm working on it.
#4

I had written an E-mail to Radio Daze about substituting the 5Z3 for my 280 and here is the reply:

We wouldnt suggested the substitution because it draws more amps from the amp - roughly 50% more. They will physically fit though.

Will there be a problem with the draw of more amps?
#5

Possibly - the old original power transformer, now running hotter to begin with at 120 volts on primary instead of rated 110VAC, will possibly overheat with even more stress on the rectifier secondary.

Just use a type 80, which is what the transformer is rated at.

Chuck




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
6TPZ and 5TPO Radio Help
Quick progress report: X7 is broken. Only one leg soldered, the other missing and the diode is cracked. I've replaced...R3Sons — 05:05 PM
6TPZ and 5TPO Radio Help
Oh...and you have electrolytic caps there. All need to go and be replaced.morzh — 04:36 PM
6TPZ and 5TPO Radio Help
Thanks, will do.R3Sons — 01:25 PM
1930s Stewart-Warner Tombstone Radio need help identifying model number
UPDATE: I was able to pick up a signal generator on the cheap (amazingly enough) on feebay and I did an IF alignment fol...captainclock1988 — 09:53 AM
Philco 91 Schematic
Hi Rod, The resistor connects to pin 4 and the ungrounded side of block 9. From pin 9 of the RF tube to one side of ...dconant — 09:34 AM
Just got a 49-1613 need to know...everything!
I just found your post. I have this exact same model, and have had it since 1985 when I was 15 years old! I performed a ...MuzzcoVW — 09:11 AM
B&K 1077B no video
Hello Tim, I would if it's a leaky Capacitor So are all 3 of those B- voltages low then ? Sincerely Richardradiorich — 01:55 AM
B&K 1077B no video
I found a schematic and think I have the problem traced down to the minus power supply. I have very low voltages that go...TV MAN — 12:41 AM
RCA 15X
I'd try replacing the bulb first and if that doesn't do it, then change the 35Z5 and see if the problem goes away.NostalgiaRadioTime — 12:28 AM
B&K 1077B no video
Hello Tim, I have that exact unit in my shop too plus a Sencore unit there are times I like one or other !!. Sincerely...radiorich — 11:07 PM

[-]
Who's Online
There are currently 10591 online users. [Complete List]
» 3 Member(s) | 10588 Guest(s)
AvatarAvatarAvatar

>