EEVblog Electronics Community Forum
A Free & Open Forum For Electronics Enthusiasts & Professionals
Welcome,
Guest
. Please
login
or
register
.
Did you miss your
activation email
?
1 Hour
1 Day
1 Week
1 Month
Forever
Login with username, password and session length
This topic
This board
Entire forum
Google
Bing
Home
Help
Search
About us
Links
Login
Register
EEVblog Electronics Community Forum
»
Electronics
»
RF, Microwave, Ham Radio
»
Can a radio rf section be aligned without access to signal gen with modulation?
« previous
next »
Print
Search
Pages: [
1
]
Go Down
Author
Topic: Can a radio rf section be aligned without access to signal gen with modulation? (Read 2836 times)
0 Members and 1 Guest are viewing this topic.
Specmaster
Super Contributor
Posts: 14483
Country:
Can a radio rf section be aligned without access to signal gen with modulation?
«
on:
February 17, 2017, 12:06:03 am »
I thought that I would have a go at restoring an old HMV transistor radio MW/LW and FM. It has become very clear that the RF section has been messed about with and requires realigning. Years ago I had a signal generator with modulation built in that gave me a 400hz signal that could be used to detect when each section was tuned correctly.
My current signal generator does not have the ability of modulation so I was wondering if there was another way of doing the alignment using the standard signal generator and an oscilloscope or is that not possible?
Logged
Who let Murphy in?
Brymen-Fluke-HP-Thurlby-Thander-Tek-Extech-Black Star-GW-Avo-Kyoritsu-Amprobe-ITT-Robin-TTi
SingedFingers
Frequent Contributor
Posts: 599
Country:
Re: Can a radio rf section be aligned without access to signal gen with modulation?
«
Reply #1 on:
February 17, 2017, 01:02:48 am »
This. Best thing is tune to a known station, tweak the VFO can until you are on top of the dial and station at the same time, then tweak the IF cans until it is loudest. Don't really need a signal gen for AM radios.
Logged
Specmaster
Super Contributor
Posts: 14483
Country:
Re: Can a radio rf section be aligned without access to signal gen with modulation?
«
Reply #2 on:
February 17, 2017, 01:06:31 am »
No this radio is a portable MW / LW and FM radio for listening to commercial broadcast stations in the UK. It has no SW or transceiver capabilities at all.
Logged
Who let Murphy in?
Brymen-Fluke-HP-Thurlby-Thander-Tek-Extech-Black Star-GW-Avo-Kyoritsu-Amprobe-ITT-Robin-TTi
LaserSteve
Super Contributor
Posts: 1375
Country:
Re: Can a radio rf section be aligned without access to signal gen with modulation?
«
Reply #3 on:
February 17, 2017, 01:24:39 pm »
A few 1n914 diodes, some resistors, a pair of decoupling caps, maybe a small inductor, and you have a crude but workable AM source with the existing signal generator. Your using the diodes as PIN switches or PIN attenuator.
Steve
Logged
"When in doubt, check the Byte order of the Communications Protocol, By Hand, On an Oscilloscope"
Quote from a co-inventor of the PLC, whom i had the honor of working with recently.
Print
Search
Pages: [
1
]
Go Up
« previous
next »
Share me
Smf
EEVblog Electronics Community Forum
»
Electronics
»
RF, Microwave, Ham Radio
»
Can a radio rf section be aligned without access to signal gen with modulation?
There was an error while thanking
Thanking...
EEVblog Main Site
EEVblog on Youtube
EEVblog on Twitter
EEVblog on Facebook
EEVblog on Odysee