Hacker Mayflower RV14

[Radio_Dave]

Upon first inspection it was obvious that the mains transformer had been working hard as there was a dollop of wax stuck to the cabinet floor. I suspected the smoothing electrolytics as it had a mushroom, between its terminals. Other, smaller, electrolytics were cased in a hard plastic but several were discoloured and swollen, so I changed these as well. The only other ‘change on sight’ components were four, distressed looking waxies.

First power up and the radio it worked, but it sounded fuzzy and the HT was only 160V, and dropping. It had to be the selenium rectifier, so I removed its innards and replaced them with 4x 1N5408’s. I’d discovered from and earlier post that the Hacker service manual had mistakes in its valve voltages, so there was nothing, useful, I could check with a voltmeter. I tried a 100R surge limiting resistor with the rectifier and got 255V at the screens of the ECL86’s and a HT of 260V. I guessed this was close enough and left it at that.

Powered up again and this time it had plenty of volume, but it still didn’t sound right. The Erie resistors were either 5 or 10% tolerance, but at best they were 20% and in the worse cases, over, 50% out! I couldn’t change them all, so I drew a line at 30% and either changed the ones above this with NOS Eire resistors or paralleled them in to the existing ones to bring their resistance back down to tolerance.

Powered up for a third time and it worked really well… job done, after a chassis clean and polish!

The station pointed and dial cord were missing,. After requesting forum help, receiving photos and a tip that the RV20 data had a re-stringing diagram, I was able to make a pointer and restring it quite easily.

The cabinet had a lot of surface scratches (must be why I got it so cheap!) and needed a bit of filler to hide a piece of chipped veneer, however it was far to good to strip. I cleaned the finish with T Cut then white spirit, lightly sanded it with P800 wet and dry, re-painted the end grain of the front panel and then applied two coats of Danish Oil… job done!

There’s always been a lot of favourable things said about this radio on the forum but I must admit that I could never see the attraction. However, now that I have one I can see what all the fuss is about. I think it’s the small size and good proportions that make it so appealing, oh... it sounds nice too

And here’s some photos.

Regards
David

[howard]

Hello Dave,

That's a really nice radio and I'm glad you like it and managed to get it working well The Hacker RV14 is at the top of my shopping list at the moment cos I have heard one working and they are good little sets.

Howard

[Nickthedentist]

Hello Dave,

Well done, that's well up to your usual standards

I too found that my RV14 had vast numbers of Rs that were out-of-spec. Changing these made a huge difference.

I would advocate adding an HT fuse - see the RV20 manual for details - as nasty things can happen otherwise.

Nick.

[Radio_Dave]

Originally Posted by Nickthedentist

I would advocate adding an HT fuse - see the RV20 manual for details - as nasty things can happen otherwise

I'll check both manuals tonight, but doesn't already have one? The fuses are those two red plugs, as seen in the chassis photo

David

[Station X]

Make sure they are fuses and that someone hasn't bridged the pins with ordinary wire. I've even seen these with a strand of wire wrapped round the pins OUTSIDE the housing.

[Nickthedentist]

Originally Posted by Radio_Dave

I'll check both manuals tonight, but doesn't already have one? The fuses are those two red plugs, as seen in the chassis photo

You may well be right, but my RV14 circuit shows that both fuses are in the primary circuit: FS1 in the voltage selector plug protecting live, FS2 in the neutral lead.

Have a look at my RV14's chassis. You can see that the chassis-mounted fuse is connected to the mains neutral wire, and that the chassis is very charred, presumably when the original mains transformer went up in a puff of smoke when the selenium rectifier went S/C. This pic is of the set as I received it, i.e. repaired and basically working, but not yet restored.

Nick.

[Nickthedentist]

In contrast, the RV20 circuit shows F1 between the HT winding and the metal rectifier, and F2 in the voltage selector in series with the live mains going to the primary.

Apologies for the poor pic, but follow the thin white twisted pair (which runs from the HT winding on the mains transformer)...

A much better arrangement all round.

It would spoil the originality somewhat, but it might be worth rewiring your RV14 this way. Alternatively, you could add a third fuse holder discreetly and fit a shorting link across the neutral fuse (as Graham mentions!).

Nick

[Radio_Dave]

Originally Posted by Nickthedentist

FS1 in the voltage selector plug protecting live, FS2 in the neutral lead

Thanks Nick, you were right. My chassis has the same fuse arrangement as your photo. I'll put an inline fuse holder between the secondary and the rectifier

David

[petervk2mlg]

What a great looking chassis!
There are a couple of those on ebay right now. Sadly the cost of postage from UK to Oz is prohibitive these days.
Maybe I'll have to move back to my old home!
Peter

[razor600]

Nice job Dave
Just brought one of these sets,looking forward to it arriving next week.
Ray....

[Radio_Dave]

Well done Ray, you won't be dissapointed!

It's been mentioned many times before, but just in case you don't know, great care is needed when removing the chassis to avoid scratching the tuning dial with the tuning dials reflector, where it bends out, just before the magic eye

David

[razor600]

Cheers for that info Dave.
will take care removing chassis.
Ray....

[Tim]

A small piece of black electrical tape or magic marker comes in handy..............allegedly!

[razor600]

Hello all
The AV14 has arrived,I have found an in line fuse holder to put in between secondary & rectifier,what amperage size fuse would you recommend ?
Ray.....

[petervk2mlg]

150ma slow blow?
Peter