Very poor reception. HMV 1127

[Jonmurphy]

Mentioned this radio before but thought this needed a new thread.

I have the above radio. After changing a couple of bits here and there and replacing all paper caps, it's now working. However reception is terrible. AM is quiet and faint with only a couple of stations being able to be received when holding the ferrite aerial. LW is just noise although Five Live can be heard faintly when touching the aerial.

All resistors check out ok on the multimeter.

The ferrite is a wax covered one with no signs of damage.

I'm waiting on a sig gen being delivered, although I've never done alignment before and don't really know what I'm doing.

So any advice on either the problem or the process of alignment would be greatly appreciated.

[FStephenMasek]

Alignment is not difficult, you just have to take your time and go through the steps in the correct order. You will need an analog volt meter to connect to the voice coil, or an oscilloscope, and a set of non-metal adjustment tools. It is also helpful to have a frequency counter to verify that the signal generator is outputting the desired frequency. Very small differences in adjustments are usually significant, but you will develop a feel for that as you perform more alignments.

[mike1 ryan1]

Hi,
I am waiting on a signal generator in the post and have not done it before so will keep an eye on how you get on, http://www.vintage-radio.com/project...indicator.html. This is a link to a project to build on here for an audio output meter, should be useful. Have bought the bits to build one, not much to it so only cheap.

Good luck,

Mike.

[Nickthedentist]

Any evidence of the cores having been twiddled?

If no, then do check other things first, e.g. cleanliness of the wavechange switch contacts, and the valve pins/sockets.

Nick.

[Jonmurphy]

No evidence of tamper at all.

So I cleaned all pins and holders and the switch contacts. No improvement.

[Jonmurphy]

After much fiddling with cores I seem to be getting somewhere.

Now have 5/6 clearish stations. Which is a big improvement on none.

Still not really clear though which leads me to suspect something else is amiss here. Also LW is slightly puzzling. It is supposed to be fixed on Radio 4 long wave, however the only station I can get is Radio 5 MW.

Does this suggest anything to anybody?

[camtechman]

LW is just noise although Five Live can be heard faintly when touching the aerial.

Might be worth checking for any o.c's on the ferrite aerials coils.

[Jonmurphy]

Five live can be heard clearly now.
Aerial coils are wax covered and undamaged.

[Bittyboy]

Originally Posted by Nickthedentist

Any evidence of the cores having been twiddled?

If no, then do check other things first, e.g. cleanliness of the wavechange switch contacts, and the valve pins/sockets.

Nick.

In my opinion I agree with Nick as I once got a Roberts RM20 radio (MW/LW only) and I could not get any reception out of it no matter what, so I decided to take the back panel off carefully and saw a few box like things with adjustment screws in the middle of them, some had wax on them to lock the screws in the pre set position and some looked tampered with, after using a small flat bladed screw driver and turning those adjustment screws very slowly one direction or the other while the radio was going, hey presto! I began getting stations on MW and even on LW too! which was just very loud humming/buzzing sound before I tried those adjustment thingys.