System A PC Modulator Issue - UK Vintage Radio Repair and Restoration Discussion Forum

ConnorFOD · 21st May 2021, 12:44 pm

Hello, I've recently purchased a PC - 405 Line modulator from a member on here. I'm having trouble getting any sort of signal on my television?

I have connected the modulator to power, I have a cable going from RF out, into an adapter to convert it to Aerial, into the tv.

Test card and tone is set to on, none of the channels on the TV or modulator show anything, however when I switch channel I am getting a change in static shown on the TV, Any ideas?

I know I will at some point have to connect to a graphics card and convert from that, but surely a test card should work just from connecting the modulator, or am I mistaken?

- Connor

FRANK.C · 21st May 2021, 6:52 pm

Hi Connor
It might help if we knew which Modulator and TV you are using.

If it is a Vol system A modulator.
Then if the test card and tone switches are on there will be a test card and test tone on whichever channel the modulator is set to.

Frank

rambo1152 · 22nd May 2021, 6:40 am

If the noise on the screen disappears and the screen goes significantly darker when the carrier is on, it's all probebly working normally.

21st May 2021, 12:44 pm	#1
ConnorFOD Triode Join Date: Mar 2021 Location: London, UK. Posts: 23	System A PC Modulator Issue Hello, I've recently purchased a PC - 405 Line modulator from a member on here. I'm having trouble getting any sort of signal on my television? I have connected the modulator to power, I have a cable going from RF out, into an adapter to convert it to Aerial, into the tv. Test card and tone is set to on, none of the channels on the TV or modulator show anything, however when I switch channel I am getting a change in static shown on the TV, Any ideas? I know I will at some point have to connect to a graphics card and convert from that, but surely a test card should work just from connecting the modulator, or am I mistaken? - Connor Last edited by ConnorFOD; 21st May 2021 at 12:52 pm.

21st May 2021, 6:52 pm	#2
FRANK.C Heptode Join Date: Feb 2006 Location: Roscommon, Ireland Posts: 697	Re: System A PC Modulator Issue Hi Connor It might help if we knew which Modulator and TV you are using. If it is a Vol system A modulator. Then if the test card and tone switches are on there will be a test card and test tone on whichever channel the modulator is set to. Frank __________________ www.electronics.frankcuffe.ovh

22nd May 2021, 6:40 am	#3
rambo1152 Dekatron Join Date: May 2010 Location: Manchester, UK. Posts: 3,626	Re: System A PC Modulator Issue If the noise on the screen disappears and the screen goes significantly darker when the carrier is on, it's all probebly working normally. __________________ -- Graham. G3ZVT