Revox B760 tuner lights up but no response to indoor aerial - UK Vintage Radio Repair and Restoration Discussion Forum

QUADGOD · 3rd Jul 2019, 6:15 pm

I purchased this with other Revox gear and this is the only problem unit.
I've no instructions so I just tried a wire off the normal round aerial out but get zero response from the vu's or through amp.
Any idea please? I'm an electrical appliance engineer but not in electronics....

SteveCG · 4th Jul 2019, 12:51 pm

I'm not familiar with this particular model, however a couple of suggestions for you:

1) Basic question, can you tune across the FM Band?

2) If so, then with the aerial connected do you hear anything on the audio output as you tune across the Band?

Quite a few tuners mute the output unless the signal is strong enough to give satisfactory stereo performance. Usually there is a way to select 'mono' operation when usually you will hear what the tuner is tuned to - and this may just be hiss.

It is possible that your aerial is not one designed for the FM band and is just a UHF TV aerial. Can you check this point please?

Marconi_MPT4 · 4th Jul 2019, 6:47 pm

These tuners are extremely sensitive and should work even with a length of ordinary wire attached for use as an aerial.

Try setting the tuning mode to manual and then check the frequency display alters as required. Set the frequency to, say 88.5MHz for Radio 2, this might be different in your area.

One other thing to check is the 'Muting Off' button located on the lower right front panel. Press this to disable quiet tuning mode i.e. inter station noise suppression. When depressed you should hear background hiss with no signal or between stations.

Is the Amber muting signal indicator illuminated, located above the muting mode switch?

Also check muting mode switch is set to inter-tuning rather than inter-stereo.

There are three audio out options. DIN and adjacent phono sockets are fixed level, the variable output is set by a control hidden under the front drop down door.

Rich

QUADGOD · 10th Jul 2019, 7:07 pm

Quote:

Originally Posted by Marconi_MPT4

These tuners are extremely sensitive and should work even with a length of ordinary wire attached for use as an aerial.

Try setting the tuning mode to manual and then check the frequency display alters as required. Set the frequency to, say 88.5MHz for Radio 2, this might be different in your area.

One other thing to check is the 'Muting Off' button located on the lower right front panel. Press this to disable quiet tuning mode i.e. inter station noise suppression. When depressed you should hear background hiss with no signal or between stations.

Is the Amber muting signal indicator illuminated, located above the muting mode switch?

Also check muting mode switch is set to inter-tuning rather than inter-stereo.

There are three audio out options. DIN and adjacent phono sockets are fixed level, the variable output is set by a control hidden under the front drop down door.

Rich

Manual tuning readout working perfectly. Muting light stays on no matter if switch is depressed or not. Noise reduction light does not come on. I've got it on fixed output into the Revox B750 mk2 amp. No hiss through amp/speakers or signal showing on vu's.
Doesn't look like a simple fix ..for me that is... unless there's something inside that may need freeing off with switch cleaner but then I'd still get a reading on vu's surely ?

Marconi_MPT4 · 10th Jul 2019, 8:14 pm

Quote:

Originally Posted by QUADGOD

Doesn't look like a simple fix ..for me that is...

Having checked the basic controls, it does indeed look as if something is amiss. You should at least get some deflection on the signal strength meter with the tuning meter moving left-centre-right when tuning through a station.

Just a thought, there are two slots for optional Dolby B decoder boards however when these are not fitted two jumper boards have to be installed otherwise the fault symptom is similar. To check what is fitted unscrew the left hand side cabinet panel and you should have one of the board options installed. If link boards (default) then make sure Noise Reduction is only set to normal.

Rich

QUADGOD · 10th Jul 2019, 8:38 pm

I assumed it would have noise reduction so I will check boards... Or if no NR maybe those link boards are not seated properly and need removing replacing?
Clutching at straws here. I purchased from a family member after a death so no one knows much about equipment to quiz over....

3rd Jul 2019, 6:15 pm	#1
QUADGOD Tetrode Join Date: Aug 2016 Location: Bedford, Beds. UK. Posts: 59	Revox B760 tuner lights up but no response to indoor aerial I purchased this with other Revox gear and this is the only problem unit. I've no instructions so I just tried a wire off the normal round aerial out but get zero response from the vu's or through amp. Any idea please? I'm an electrical appliance engineer but not in electronics....

4th Jul 2019, 12:51 pm	#2
SteveCG Nonode Join Date: Jun 2009 Location: Herefordshire, UK. Posts: 2,495	Re: Revox B760 tuner lights up but no response to indoor aerial I'm not familiar with this particular model, however a couple of suggestions for you: 1) Basic question, can you tune across the FM Band? 2) If so, then with the aerial connected do you hear anything on the audio output as you tune across the Band? Quite a few tuners mute the output unless the signal is strong enough to give satisfactory stereo performance. Usually there is a way to select 'mono' operation when usually you will hear what the tuner is tuned to - and this may just be hiss. It is possible that your aerial is not one designed for the FM band and is just a UHF TV aerial. Can you check this point please? Last edited by SteveCG; 4th Jul 2019 at 12:53 pm. Reason: spelling

4th Jul 2019, 6:47 pm	#3
Marconi_MPT4 Heptode Join Date: Mar 2011 Location: Dorset, UK. Posts: 521	Re: Revox B760 tuner lights up but no response to indoor aerial These tuners are extremely sensitive and should work even with a length of ordinary wire attached for use as an aerial. Try setting the tuning mode to manual and then check the frequency display alters as required. Set the frequency to, say 88.5MHz for Radio 2, this might be different in your area. One other thing to check is the 'Muting Off' button located on the lower right front panel. Press this to disable quiet tuning mode i.e. inter station noise suppression. When depressed you should hear background hiss with no signal or between stations. Is the Amber muting signal indicator illuminated, located above the muting mode switch? Also check muting mode switch is set to inter-tuning rather than inter-stereo. There are three audio out options. DIN and adjacent phono sockets are fixed level, the variable output is set by a control hidden under the front drop down door. Rich __________________ To an optimist a glass is half full; a pessimist half empty; an engineer twice as big as need be! Last edited by Marconi_MPT4; 4th Jul 2019 at 7:03 pm. Reason: Additions

10th Jul 2019, 8:38 pm	#6
QUADGOD Tetrode Join Date: Aug 2016 Location: Bedford, Beds. UK. Posts: 59	Re: Revox B760 tuner lights up but no response to indoor aerial I assumed it would have noise reduction so I will check boards... Or if no NR maybe those link boards are not seated properly and need removing replacing? Clutching at straws here. I purchased from a family member after a death so no one knows much about equipment to quiz over....