Bush VHF54 FM Aerial

[Daventry 5XX]

Hi all

I need to construct some sort of external aerial for the FM on a Bush VHF54
that I am working on.

The internal aerial is damaged beyond repair,but Ive heard that they are a waste of time anyway

As a novice I dont really know whats required.

Ive tried just putting a length of wire into the two holes but that didnt seem to make any difference.

Any suggestions please

Alan

[G8HQP Dave]

Have you tried Google? Plenty of designs on the web. Look for folded dipole.

[Nickthedentist]

Are you getting any FM reception at all? 3 feet of insulated wire poked into either of the holes should give you some stations, assuming you don't live miles away from the transmitter.

Fancier designs will be better, but not drastically so, IMHO.

[Daventry 5XX]

Nothing at all

I live in North Wales,near Caernarfon,probably not ideal,some big mountains in the way

Alan

[Nickthedentist]

Can you get lots of stations on a modern FM set?

These early VHF sets are rarely very sensitive and you might have to replace the two EF80s (and all the wax/paper caps) to get anywhere near good results.

[TimS]

Originally Posted by Dickiebird

Nothing at all

I live in North Wales,near Caernarfon,probably not ideal,some big mountains in the way

Alan

There's an FM transmitter on Anglesey, so just small hills in the way.

In terms of such hills, we are probably more remote than yourself from a transmitter and either a half wave vertical dipole or a folded dipole, both connected via coax, and without baluns, work reasonably here, though there is room for improvement (its on the things-to-do list).

The quickest way of getting the former is to put 75cm of wire in one hole and point it vertically up, plus 75cm of wire in the other and point vertically down. If you don't get anything with that there may be something wrong with the radio.

-- Tim.

[maninashed]

Hi Alan, I know reception can be bad in your area, but can you normally receive any vhf stations on a modern set in your house where you are working on the Bush? If the answer is no, then its not surprising.
Ive recently restored a Bush VHF41, which is not too disimilar to yours, the 2 EF80s in the vhf tuner unit have to be in good fettle, they are not the best valve for this position but I think Bush just used up what they were used to. They were later changed to ECC85/UCC85. Not sure of your level of expertise but, have you changed all those nasty leaky Hunts caps in the vhf tuner can (and everywhere else in this set), they are a real pain to dig out, but its the only way Im afraid! Check also the 5uf electrolytic in the discriminator circuit its connected +to chassis. Also check the EABC80, the diodes need to be good, they are used in the discriminator too. Hope this helps
Bill

[Daventry 5XX]

Hi Bill

I've changed both EF80's.......no improvement

I've now got the VHF tuner in bits,most of the Hunts caps are cracked so I'll change them and take it from there.

I took the opportunity to check the resistors,they all test good,no problems there.

I'm in the process of also changing all the other wax caps,so hopefully I will see some improvement.

Thanks for your help

Alan

[maninashed]

Alan, take your time with that tuner unit, and try and disturb things as little as possible, draw a quick sketch before you dismantle or take some good digital photos so you know EXACTLY how it all should be, because it will be very difficult to see where youve gone wrong if you make a mistake and have to find it later. Ive just done a Bush VHF 90 and that is superb on VHF radio 2, nice neat compact set. Different vhf tuner unit though.
Ive no doubt that you will see a big improvement once all those leaky caps are out, probably run cooler too as there will be less ht current required.
Regards
Bill

[Daventry 5XX]

I did notice that my current limiter was glowing a bit more than usual,clearly something is pulling a bit too much juice.