Fidelity HF29
 

Can anyone please help ?
My friend has asked me to repair his Fidelity HF29 record player.
My first job was to service the deck as it was totally seized, then I discovered the cartridge had died. The cartridge is a BSR X1M the spec says it has over a volt output and I am struggling to find something compatible. Tried a Sonotone, just as a test, with an output of 450mv I get sound but very weak.
If you put your finger on the red lead of the cartridge there is a very loud hum which I would expect so the amp seems OK.
The amp however is a very basic transistor type, a bit Heath Robinson if I am honest.
That is one issue, but since I have been working on it a wire has come adrift it feeds the power to the amp from a very small transformer. It's on the primary side one lead comes from the deck but it's the other one that's broken off.
I am assuming that it connects to the common or earth side of the amp , but not 100% sure.
Does anyone ever worked or seen this model ?
Any help/advice would be amazing.

Re: Fidelity HF29
 

There appears to be very little information on this player. Perhaps you could post a picture of the amplifier and identify the active devices.

Re: Fidelity HF29
 

Here's a couple of pictures, hope they help.
I have tagged the suspect wire to the strip just above the right hand top screw.

Re: Fidelity HF29
 

I would imagine that wire connects to one of the other motor wires at the on/off switch, not sure which one though at the moment but to me it looks dodgy where it's connected to at present because it means that one end of the transformer's primary is connected to what I think is the amplifier's +ve rail which appears to have an earth connection, if the earth connections weren't sound the +ve rail could become live.

Lawrence.

Re: Fidelity HF29
 

Hi, this is one of those rare models between valve and solid state production.
The little transformer seems to be dropping the 90 volt tap from the motor so the black wire that came loose must go to one side of the mains.
The other black wire is connected to the white from the motor which is the 90 volt tap.
Can you see the remains of a soldered wire anywhere near the mains switch. The other clue is in the length of the wire. It definitely looks to have come from the switch area.

Hope this helps.
David.

Re: Fidelity HF29
 

Thank you I will definitely check that area out and post a reply later.

Re: Fidelity HF29
 

Switch has now failed, nothing on the internet.......is it worth it ?

Re: Fidelity HF29
 

Do you mean the on/off switch on the volume control?

Re: Fidelity HF29
 

Just bridge the switch out for the time being. If you can get the amp working it's probably worth repairing or replacing the switch.

Re: Fidelity HF29
 

The volume control is ok but the power switch has gone, no click and it's in the off position.
Because of the way it's mounted there is nothing on the internet, however, I could fit a small rocker switch somewhere as it's not going to be sold but used at car boot sales just to attract customers.

]Bridged the switch and it works again , still trying to find a high output cartridge.
Do you know anything about a Tetroid TC12M1 cartridge, a friend has one and thought it was a med to high output , but I can't find anything about it on the internet. Tried a sonotone 9ta cartridge and you can hear it but at full volume.

Re: Fidelity HF29
 

It's quite unusual for a transistor amplifier to use (or need) a high-output cartridge.
Do bear in mind that any NOS cartridge, whether medium or high output, you buy for this is going to cost in the region of £35 to £40. The 9TA Sonotone cartridge you are testing it with has a relatively low output for a medium output cartridge. It is a high quality one and not really suited to this class of record player. I am not familiar with the "Tetroid" type.

Re: Fidelity HF29
 

If you are trying to do a low cost repair you could try fitting one of the cheap red Chinese cartridges available for less than £2. These are not high output cartridges, but usually have enough output for a transistor amp.

I suspect there is some other fault which is reducing the volume. The difference between 500mV and 1V output is only 3dB which is barely audible.

Re: Fidelity HF29
 

Ok. Thank you everyone for your input.
I might try a cheap one just as a guide to the amp's ability.
A circuit diagram at this stage would be useful!

Re: Fidelity HF29
 

Just remember the cheap Red Cartridges do not come with a fixing bracket, I bought a bracket from “get the needle” for about £7.
Cheers
John

Re: Fidelity HF29
 

It looks as if the volume pot is mounted onto the PCB, any of the many switched pots of the correct value would be suitable to replace that.
may not be the correct value but one like this should work. https://www.ebay.co.uk/itm/350819414984?

Regarding the circuit, find a similar record player (any make) with similar transistors and use that as the basis to make notes on, then compare to what you have and draw on what is different.
It cant be that difficult, there are probably only 3 or 4 transistors, and you may actually be able to leave something to help the next person to get one of these.

Mike

Re: Fidelity HF29
 

In the past I've used switched pots. similar to that in the eBay link in Mike's post #15, with the nearest available value to the original (e.g., if original was 50k -used a 47k, etc.) If the new pot. couldn't be soldered directly to the P.C.B. I 'hard-wired' it instead.

Re: Fidelity HF29
 

Looks like it wont be so easy, I can only find one other record player with 3 transistors and no driver transformers, but the preamp one is silicon, your one looks like a germanium transistor.
https://www.radiomuseum.org/r/balcombe_532.html
I happen to have this one in my shed.

Mike

Re: Fidelity HF29
 

An interesting thread. After all these years, I have never come across a Fidelity HF29.
The HF35 was one of, if not the last, Fidelity valve record player made (there was a transistor version also called HF35) but in the Fidelity model numbering sequence the 29 precedes this. I'm guessing therefore that this is very first transistor player they ever made. The BSR UA25 deck dates it as from mid-1964 onwards.

Re: Fidelity HF29
 

You can mount the cartridge temporarily with a bit of blu-tak, though obviously that's not a good long term solution.

Re: Fidelity HF29
 

Tried one of those cheap red cartridges a friend had and still have low output, quality is ok just low.
The level is about loud enough for a small room flat out.
I can only assume perhaps the amp has gone low gain ?
The volume control/ off-on switch is a 1m ohm which I am finding difficult to find even if I hard wire one the spindle would be wrong shape for the knobs as they are on extended spindles.
I will keep looking but it's taking up a lot of time for something that's not mine!