Hacker Speaker Survey
 

Hi All,

My forum and web searches have been getting me confused, so maybe this will help...

Having just acquired the start of a Hacker collection, I'm curious about the speakers that were used. Specifically, I'm trying to work out if there was a concerted effort on Hacker's part to put different speakers in the VHF Herald and Sovereign II - this is because (a) these are the two main models I have, and (b) I've read lots of comments here about how the Herald is considered to sound better than the Sovereign. My initial observations would agree with this, but having just got my Sovereign going, I've stripped down the Herald - and am wishing I'd held on a while so I could have made detailed comparisons...

Anyway, here goes:

Sovereign II RP25 (27794): Goodmans speaker with a painted grey frame. There are no bolts in the magnet assembly.

VHF Herald RP37A (22003): Elac speaker, also with a grey painted frame. This has a large magnet - probably 3 inches in diameter, and produces much more low bass than the Goodmans above.

Looking at the various pictures on-line, the Goodmans seems to be more popular, and I've seen it fitted to both receivers. I've also seen another Goodmans with has 3 bolt-heads on the rear of the magnet. I've also spotted what looks like a Celestion model.

Don't feel you have to restrict yourselves to these 2 models - I also have a Hunter RP37A with an Elac, although this looks more like the Goodmans (albeit unpainted), and a Mini-Herald with a Goodmans speaker that is very similar to the model fitted to my RP25.

I realise that production shortages/changes, plus in-service replacements could confuse this ;)

Thanks in advance,

Mark

Re: Hacker Speaker Survey
 

My Hacker:

RP18 Goodmans 'speaker. Grey painted metal frame, plated magnet with 3 brass pozidrive screws in line. Sticky label on magnet.

I use this set with a 4.6 Ahr Li-Poly rechargeable battery which started life as a 22V unit and developed a faulty cell. The defective cell (3V) is now shorted out. Although the audio amplifier board has to be moved to fit this in, these batteries give a very impressive performance.

Thanks for the tip concerning the 5 pin plug.

Leon.

Re: Hacker Speaker Survey
 

All three Hacker sets I have here - Sovereign RP18 black, Sovereign II RP25 blue (15858) and Herald (AM only) have a Goodmans speaker with a painted grey frame and 3 bolts in the magnet assembly. (Speaker says made in Wembley Middlesex)

Re: Hacker Speaker Survey
 

My Hacker Sovereign RP25 mk2 blue has the Goodmans speaker with painted grey frame and three bolts. As above the label says made in England Wembley Middlesex

Re: Hacker Speaker Survey
 

What's the non descript silver one? Is this a Goodmans in disguise or something else?

Regards,


Andy

Re: Hacker Speaker Survey
 

Total so far:

• Goodmans with no bolts: 1 (My RP25)
  
• Goodmans with 3 bolts: 5 (2 in RP18, 2 in RP25, 1 in AM Herald)
  
• Celestion: none so far
  
• Elac (large magnet): 1 (my VHF Herald)
  
• Elac (small magnet): 1 (my Hunter)

Anyone else got a VHF Herald?

Re: Hacker Speaker Survey
 

Hi Andy - is this the one you have? Could you post a picture?

Which reminds me - here are pictures of my Sovereign II are here: https://www.vintage-radio.net/forum/...2&postcount=12, and my VHF Herald and Hunter are below:

Re: Hacker Speaker Survey
 

Just going through the pictures at Simon Spiers excellent site (http://www.hacker-radio.fotopic.net/), where I could make a positive identification:

• Goodmans with no bolts: 1 (AM Herald RP35
• Goodmans with 3 bolts: 4 (early RP10, Helsman, RP20 AM Herald, RP18 Sovereign
• Celestion: 1 (Sovereign RP25)

There were others, but I decided to stick with the 5 by 8 inch models...

This brings the totals up to:

• Goodmans with no bolts: 2 (My RP25, AM Herald RP35)
• Goodmans with 3 bolts: 9 (3 in RP18, 2 in RP25, 1 in AM Herald RP20, 1 in Jonsters AM Herald unnumbered, early RP10, Helsman RP36)
• Celestion: 1 (Sovereign RP25)
• Elac (large magnet): 1 (my VHF Herald)
• Elac (small magnet): 1 (my Hunter)

Thanks again - keep them coming :)

Re: Hacker Speaker Survey
 

Here's a piccy. It's from an RP25. It has no name - just 16 ohm written on it. Sounds nice though!

Andy

Re: Hacker Speaker Survey
 

Hi Andy,

I reckon that's a Celestion - have a look at the terminal board, I think that's the Celestion logo between the terminals and the magnet. Also, have a look at this picture: http://www.hacker-radio.fotopic.net/p37254870.html

Updated scores:

• Goodmans with no bolts: 2 (My RP25, AM Herald RP35)
• Goodmans with 3 bolts: 9 (3 in RP18, 2 in RP25, 1 in AM Herald RP30, 1 in Jonsters AM Herald unnumbered - probably RP30, early RP10, Helsman RP36)
• Celestion: 2 (both Sovereign RP25)
• Elac (large magnet): 1 (my VHF Herald)
• Elac (small magnet): 1 (my Hunter)

Thanks again :)

Re: Hacker Speaker Survey
 

Ah yes, so it is. Fancy sneaking the name in there!

Cheers,


Andy

Re: Hacker Speaker Survey
 

My VHF Herald has a Grey Goodmans speaker, no bolts and carries a silver disc label "Made in England - Goodmans Loudspeakers Ltd".

Re: Hacker Speaker Survey
 

Thanks, that sounds like the speaker in my RP25. Another for the total - also, I've trawled the images in the Hacker Radio Yahoo group (http://groups.yahoo.com/group/hackerradiogroup/), plus I've found a few more images on the forum. The amended the scores are as follows:

• Goodmans with no bolts: 6 (My RP25, AM Herald RP35, 2 in VHF Herald RP37A, Helsman RP36, Hunter RP36)
  
• Goodmans with 3 bolts: 15 (6 in RP18, 4 in RP25, 1 in AM Herald RP30, 1 in Jonster's AM Herald unnumbered - probably RP30, early RP10, Helsman RP36, Marine Herald RP32)
  
• Celestion (silver frame): 3 (VHF Herald RP37A, 2 in Sovereign RP25)
  
• Celestion (black frame): 3 (2 in Sovereign RP25B, VHF Herald RP37A)
  
• Elac (large magnet): 3 (mine + 2 other VHF Herald RP37As)
  
• Elac (small magnet): 1 (my Hunter RP38A)

I've also read that RP18s use a 30 ohms speaker, so that's another difference that is worth remembering, but probably complicates my survey unnecessarily at this stage :)

Edit: plus a couple more from www.richardsradios.co.uk

Re: Hacker Speaker Survey
 

Hello,

Have just received another entry, the revised scores follow:

• Goodmans with no bolts: 7 (My RP25, 2 AM Heralds RP35, 2 in VHF Herald RP37A, Helsman RP36, Hunter RP38)
• Goodmans with 3 bolts: 15 (6 in RP18, 4 in RP25, 1 in AM Herald RP30, 1 in Jonster's AM Herald unnumbered - probably RP30, early RP10, Helsman RP36, Marine Herald RP32)
• Celestion (silver frame): 3 (VHF Herald RP37A, 2 in Sovereign RP25)
• Celestion (black frame): 3 (2 in Sovereign RP25B, VHF Herald RP37A)
• Elac (large magnet): 3 (mine + 2 other VHF Herald RP37As)
• Elac (small magnet): 1 (my Hunter RP38A)

From the data I'm thinking that we can draw the following (tentative) conclusions:

1. The Goodmans speaker was the "general purpose" model that was used in most models. It is available in two versions: the earlier version had 3 bolts, later ones don't. Check the impedance!

2. The Celestions were only fitted to RP25 Sovereigns and VHF Heralds. Does this suggest the Celestion was considered to be "better", or was it just a question of availability or similar? Until I can hear one, I'll reserve judgement... Later versions had a black chassis.

3. The large magnet Elac was only fitted to VHF Heralds. Again, does this mean it's better? Based on initial tests, I think so, but will report fully once I've put my Herald back together again :)

4. To put this another way, VHF Heralds generally had Elac or Celestion speakers, but Goodmans occasionally appear.

5. Finally, the Elac with the small magnet was only fitted to RP38A Hunters (a bold statement given the sample size of 1!).

We know that the sets are near-identical electrically, yet people report sound quality differences between them. I hope that this data supports my view that the choice of speaker is responsible. But having said that, they all sound pretty damn good :)

Thanks again for your help, and please feel free to continue submitting data.

Mark

Re: Hacker Speaker Survey
 

RP38A unmarked gold colour, 58HE/146 15(ohm symbol) on the back and 38 written on it in yellow chinagraph.

Re: Hacker Speaker Survey
 

Thanks - that's the same as my RP38A - the Elac label should be on the side of the magnet near the terminals, but probably fell off sometime in the last 40 years...

Something else I recently realised: the large-magnet Elac is only fitted to the later RP37A. The earlier RP37 models used the T304 FM tuner, which is physically larger than the later T309, and precludes the use of this speaker. The picture I'm looking at now shows a "no bolts Goodmans", and it looks like a tight fit. So, was the Celestion speaker ever fitted to the original RP37?

List now amended in light of new info and a couple more sets coming my way...

• Goodmans with no bolts: 9 (My RP25, AM Herald RP30*, 2 AM Heralds RP35, Helsman RP36, 2 in VHF Herald RP37, 1 in VHF Herald RP37?**, Hunter RP38)
• Goodmans with 3 bolts: 15 (6 in RP18, 4 in RP25, 1 in AM Herald RP30, 1 in Jonster's AM Herald unnumbered - probably RP30, early RP10, Helsman RP36, Marine Herald RP32)
• Celestion (silver frame): 3 (2 in Sovereign RP25, VHF Herald RP37A)
• Celestion (black frame): 3 (2 in Sovereign RP25B, VHF Herald RP37A)
• Elac (large magnet): 3 (VHF Herald RP37A)
• Elac (small magnet): 2 (Hunter RP38A)

* The AM Herald RP30 having a no-bolt Goodmans seems a bit anomalous, but this set is incomplete, and it's possibly not the original speaker. More on that when it arrives...

** Top Cap, is your VHF Herald an RP37 or RP37A?

The emerging pattern is starting to make some sense now. The conclusions can be amended slightly:

1. The Goodmans speaker was the "general purpose" model that was used in most models. It is available in two versions: the earlier version had 3 bolts, later ones don't, and it's available in at least two impedances.
   
2. The Celestions were only fitted to RP25 Sovereigns and VHF Heralds. Later versions had a black chassis.
   
3. The large magnet Elac was only fitted to RP37A VHF Heralds.
   
4. RP37A VHF Heralds generally had Elac or Celestion speakers, but Goodmans were used for the earlier RP37 (is this exclusively the case?)
   
5. Or, the Goodmans speakers were used exclusively until the advent of the T309 tuner (RP25A and RP37A)?
   
6. Finally, the Elac with the small magnet was fitted to RP38A Hunters, and probably later models throughout the 1970s.

Thanks again - hopefully this is useful to someone out there :)

Mark

Re: Hacker Speaker Survey
 

Hi Mark, my VHF Herald is a RP37 fitted with the T304 Tuner.
Les

Re: Hacker Speaker Survey
 

Thanks Les, just as suspected :)

Will include that info next time I update the scores...

Re: Hacker Speaker Survey
 

Hi Mike,

Here are mine:-

RP18 Ser.00915 (very early). Goodmans, grey frame, metallic magnet (looks cadmium plated and pacified), Silver label, 3 screws.

RP18 Ser 32449. Goodmans, grey frame, metallic magnet (looks cadmium plated and pacified), Silver label, 3 screws.

RP25 Ser 22597. Goodmans, grey frame, metallic magnet, (looks cadmium plated and pacified), Silver label, 3 screws.

RP25 Ser 39794. Celestion, silver frame and magnet.

RP25A Ser 55683. Celestion, silver frame and magnet.

RP25B Ser 91060. Celestion, black frame, silver magnet. (Unusual combination?).

RP35 Ser 25325. Goodmans, grey painted frame and magnet.

RP36 Ser 09527. Goodmans, grey painted frame and magnet.

RP37A Ser 17737. Celestion, silver frame and magnet.

Regards,

Ian

Re: Hacker Speaker Survey
 

What a lovely image this conjures up ;)

Re: Hacker Speaker Survey
 

Hi Ian,

Many thanks for that - it must have taken you ages to compile! I've updated the list to include them:

So your results reinforce my conclusions pretty well - many thanks again.

I would correct my earlier point: It's clear that Hacker started using the Celestion in the RP25 before the tuner change. So far, the data shows that all RP37s have a Goodmans speaker, so I'd be interested to hear from anyone with an RP37 with a Celestion speaker.

Updated conclusions - changes in bold:

1. The Goodmans speaker was the "general purpose" model that was used in most models. It is available in two versions: the earlier version had 3 bolts, later ones don't, and it's available in at least two impedances.
   
2. The large magnet Elac was only fitted to RP37A VHF Heralds.
   
3. The Celestions were only fitted to later RP25 Sovereigns and VHF Heralds (probably only RP37A. Later versions had a black chassis.
   
4. An RP25 might have an early Goodmans with bolts, the later Goodmans sans bolts*, or a Celestion! I presume it depends on serial number, along with the usual production variances - trying to drill down further might be going too far ;)
   
5. RP25As and Bs should have the Celestion speaker... There's every chance that speakers in the RP25B sets will have a black frame.
   
6. Finally, the Elac with the small magnet and gold-coloured frame/magnet was fitted to RP38A Hunters, and possibly later models throughout the 1970s (although according to the 1975 brochure, all other sets had a smaller 5 by 7" speaker, but from the pictures I've seen, I'm pretty sure it's still made by Elac).

* The only RP25 I know about with a no-bolts Goodmans is my set. Is my speaker non-original - perhaps they switched straight from bolted-Goodmans to the Celestion? :-/

Thanks as always,

Mark :)

Re: Hacker Speaker Survey
 

I have RP37A, RP35, and RP25 all having Goodmans speakers.
My RP25A has a plated (sivered appearance) chassis with no maker indication. I think that the RP25 sounds better than the RP25A. It has a more open uncoloured quality on speech.

Re: Hacker Speaker Survey
 

Hello, and welcome :)

Thanks for the info - of the Goodmans you mention, do any of them have 3 bolts on the magnet, or are they the later type with no bolts?

Also, your silver speaker on the RP25A is most likely a Celestion - have a close look at the board that holds the input terminals and you should see "Celestion" written there...

Once you've got back with the details, I'll be able to add them to the stats, along with details of a few more that I've recently seen or purchased... I'm especially interested in your subjective comments, which, now that the pattern is emerging, is probably the next logical question - but that's another thread ;)

Thanks again,

Mark

Re: Hacker Speaker Survey
 

Hello Mark
You are right about the RP25A s/n 57394 having a Celestion speaker, never noticed the makers name on the terminal strip before.
The RP35 s/n 09784 has a magnet with three bolts whereas the RP37A s/n 26568 and Rp25 s/n 05711 have no bolts.
I hope this information is useful.

Robin

Re: Hacker Speaker Survey
 

Hi Robin,

Thanks for the update - and don't worry; that "Celestion" label is easily missed :)

Taking your info, plus some more recent purchases and other sets that I've seen or fixed since the last update:

So this shows up an inconsistency - your RP37A has a Goodmans speaker, which goes against the conclusions so far. This suggests that your speaker might not be the original model - RP37As should have left the factory with Celestion or large-magnet Elacs. But as you seem to prefer the Goodmans to the Celestion, this sounds like a good result :)

As before, the latest version of the conclusions in light of new data - not only from here, but from service manuals (thanks, Paul!), pictures on websites, etc. Changes in bold:

1. The Goodmans speaker was the "general purpose" model that was used in most models. It is available in two versions: the earlier version had 3 bolts, later ones don't, and it's available in 15 ohm and 30 ohm versions.
   
2. The large magnet Elac was only fitted to RP37A VHF Heralds.
   
3. The Celestions were only fitted to later RP25 Sovereigns and VHF Heralds (perhaps only the RP37A, but more input welcome). Later versions had a black chassis.
   
4. An RP25 might have an early Goodmans with bolts, the later Goodmans sans bolts, or a Celestion! I presume it depends on serial number, along with the usual production variances - trying to drill down further might be going too far ;)
   
5. RP25As and Bs should have the Celestion speaker... There's every chance (but no guarantee) that speakers in the RP25B sets will have a black frame.
   
6. The change from early to late Goodmans speakers that occurred during the life of the RP25 is also seen in the AM Herald RP35 and contemporaries. This change is close to the change from germanium to silicon AM IF panels.
   
7. Finally, the Elac with the small magnet and gold-coloured frame/magnet was fitted to RP38A Hunters, and possibly later models throughout the 1970s (The Sovereign III family (Black Knight, Super Sovereign, etc) used a smaller 5 by 7" speaker, and I've no idea who makes that. From a picture of a Sovereign IV, it looks like an Elac, but it's hard to be sure).

Thanks again,

Mark :)

Re: Hacker Speaker Survey
 

Another sample-

RP37A VHF Herald 31084

Elac Speaker

Re: Hacker Speaker Survey
 

hi i just picked up a hunter rp38 and the speaker is a grey metal frame with
goodmans loudspeakers ltd made in england on a shiny label stuck to the magnet
my super sovereign's speaker has a black frame with a frame around the magnet alas no markings probably the sticker fell off or something.sounds nice though

Re: Hacker Speaker Survey
 

Hi, I have a Sovereign 111 which has a large black speaker. At the time I asked Hacker its make and I was told Peerless.

Re: Hacker Speaker Survey
 

Thanks Chris - I've also seen a couple more VHF Heralds with that Elac...

Conclusions, once again refined from new data. Changes in bold:

1. The Goodmans speaker was the "general purpose" model that was used in most models. It is available in two versions: the earlier version had 3 bolts and were 15 or 30 ohms, later ones have no bolts and were 15 ohms.
   
2. The large magnet Elac was only fitted to RP37A VHF Heralds.
   
3. The Celestions were only fitted to later RP25 Sovereigns and VHF Heralds (perhaps only the RP37A, but more input welcome). Later versions had a black chassis.
   
4. An RP25 might have an early 15 ohm Goodmans with bolts, the later Goodmans sans bolts, or a Celestion!
   
5. RP25As and Bs should have the Celestion speaker... There's every chance (but no guarantee) that speakers in the RP25B sets will have a black frame.
   
6. The change from early to late Goodmans speakers that occurred during the life of the RP25 is also seen in the AM Herald RP35 and contemporaries. This change is close to the change from germanium to silicon AM IF panels. The handle also changed sometime around here.
   
7. The Elac with the small magnet and gold-coloured frame/magnet in 15 ohm form was fitted to RP38A Hunters. Early RP38 Hunters used the later Goodmans.
   
8. The Sovereign III family (Black Knight, Super Sovereign, etc) used a smaller 5 by 7" speaker, which has no identifying labels or markings but at the time, Hacker told forum member "safria17" that is was made by Peerless. The Sovereign IV and RPC1 marked a return to the 5" by 8" Elac, this time in 4 ohm form. Other smaller sets from this time used Philips and Audax speakers.
9. For the sake of completeness, the Mini-Herald, Autocrat, Democrat and Harrier models used 4" by 6" speakers, made by Goodmans, Celestion and possible Elac.

Special thanks to Safria17 - that's really useful information :)

Mark :)

Re: Hacker Speaker Survey
 

Thanks Darren - I did suspect this was the case with the early non-A model, but nice to have it confirmed :)

Re: Hacker Speaker Survey
 

hi mark.
the rp 38 sounds real nice.
sorry to add to the confusion but yesterday i picked up a rp72mb sovereign III
with a large black speaker marked 4 ohms.
twinned with my rp75's speaker no markings im afraid

regards darren

Re: Hacker Speaker Survey
 

Hi Darren,

Yes, that fits in with point 8 above. I've got 4 of them and none of them have any kind of markings. Sound good though, despite having a slightly smaller cone area than the others. The one I measures resonates at 93Hz - the later Goodmans is more like 110Hz IIRC.

I'm not collecting numbers on the Sov III family because they all had the same speaker - unless anyone knows differently?

Re: Hacker Speaker Survey
 

Picked up an RP38A today, has an Elac speaker in it. If you want any further info just let me know...

Josh.

Re: Hacker Speaker Survey
 

Thanks Josh - I've just taken delivery of a rather nice RP38 (non A, single tone control). It has an Elac speaker as well which looks identical to the later ones like you've probably got, only the "basket" is painted grey. It's marked 58HE/146, just like the later ones...

So, another conclusion to add to the list: Earlier RP38s had the standard no-bolt Goodmans, later ones had the Elac, but the earlier examples of this unit had a painted chassis.

Darren, just out of interest, what is the serial number of your RP38 with a Goodmans unit?

Thanks all,

Mark

Re: Hacker Speaker Survey
 

hi mark the serial number of my rp38 is 08299. assuming that it is the number
stamped onto the alluminium top right of the set,forgive me im still learning

regards darren

Re: Hacker Speaker Survey
 

Yup - that's right. My RP38 is 11546, somewhat later than yours...

(If you don't already know about it, there's a dedicated Hacker group here: http://groups.yahoo.com/group/hackerradiogroup/ - it's a useful compliment to this site, and full of useful resources. You'll find a database of Hacker serial numbers, and you might like to add your set to this...)

Cheers,

Mark :)

Re: Hacker Speaker Survey
 

hi mark

thanks for the info i will go and have a look at the hacker site

cheers

darren

Re: Hacker Speaker Survey
 

The Hacker on the table in front of me (not mine!):

Sovereign II - (serial 41921? sticker on the turntable underneath)
Goodmans speaker, three large screw heads on magnet, grey paint frame.
I don't think the bass is very good for such a monster.

Alan.

Re: Hacker Speaker Survey
 

Hi Alan,

I suspect that's not the original speaker. Looking at the database on the Yahoo Hacker group, that serial number is either late RP25 or early RP25A - meaning that either the later Goodmans speaker with no bolts should have been fitted, or, more likely, a silver Celestion. I've got two RP25s with earlier serial numbers (27794, 28560) that have the later Goodmans speaker, and my early RP25 with your speaker is 08259.

For what it's worth, all 3 of my Celestion speakers have rubbing voicecoils to varying degrees. Are they less reliable than the Goodmans? I've got many of the Goodmans speakers in all versions, and they all work perfectly.

Regarding the bass, it's worth running through the amplifier checks in the service manual, which will eliminate any problems with aged capacitors. But, Hacker didn't attempt to produce a bloated bass end, preferring instead to achieve a smooth, non-resonant sound that was more akin to hi-fi (obviously not as extended). That contrasts sharply with the Grundig set I'm working on at the moment, where the excessive amounts of bass boost combine with the plastic case to produce a bass-heavy sound that is initially impressive, and fine for background use, but quickly becomes tiring when listened to critically.

Also, check the impedance - if it came from an earlier set (e.g. RP10, RP18, RP30/31/32), it might be 30 ohms.

Thanks,

Mark :)

Re: Hacker Speaker Survey
 

Not sure if you're still collecting speaker info, but here's the gen on my newly-acquired RP-38a:

Serial number (this is the one physically stamped into the metal on the underside of the tuner assembly at the top of the radio, right?): 45208 (mains adaptor, separate bass/treble controls)

Speaker make - Elac

Do you need any more info?

Re: Hacker Speaker Survey
 

Thanks Sam :)

The "A" in the model number essentially signifies bass and treble controls. Earlier non-A models had just a single tone control - the amplifier was different as well, but you get the idea... Yes, I would expect an Elac here - only the very first non-A models had a Goodmans...

Enjoy ;)

Re: Hacker Speaker Survey
 

I've just picked up a black RP25A Sovereign II s/n 56626 and it is fitted with a silver Celestion 15 ohm speaker with no bolts.

Re: Hacker Speaker Survey
 

Thanks Johnster - that's the speaker I'd expect to find in there, and I've added your set to the database on the Hacker Radio Yahoo group ;)

Mark

Re: Hacker Speaker Survey
 

My black RP25 Sovereign II, s/n 14824, has a grey painted Goodmans 15 ohm speaker with 3 bolts.

Eamonn

Re: Hacker Speaker Survey
 

Hi Eamonn,

Thanks for that - it fits in with expectations, which is always nice :). And your set was added to the Hacker group database some time back as well. I presume that's it in your avatar?

Perhaps it's time to revise the conclusions:

5" by 8" Loudspeakers:

The Goodmans loudspeaker was the "general purpose" model that was used in many of the larger sets. It is available in two versions: the earlier ones had 3 bolts visible on the rear of the magnet, which was unpainted. These were 30 ohms in the earlier sets (RP10, 18, 30/31/32). This speaker was also seen in early RP25/35/36 sets, but in 15 ohm guise. Later ones, also 15 ohms and also seen in the RP25/35/36 (and by now the RP37), have no bolts and the magnet is painted the same colour as the chassis. The change happened at around the time Hacker switched from germanium to silicon in the AM sections of the set (the handle style also changed around this time).

Later in Sovereign II and VHF Herald production, the Goodmans loudspeaker was replaced by a Celestion speaker (AM-only sets retained the Goodmans). This new speaker has a silver painted chassis and magnet, and "Celestion" is pressed into the terminal board. Roughly, this change happened just before the change from RP25 to RP25A.

Later versions of the Celestion had a black chassis (retaining the silver magnet). These are seen in later RP25B production (no-one has spotted one in a late VHF Herald yet - it's possible that VHF Herald production stopped before the Sovereign - certainly there was never an RP37B).

Note that the Celestion doesn't fit in an AM Herald (RP35) because the switchboard interferes with the slightly larger chassis.

An alternative loudspeaker - an Elac with a large ceramic magnet - was usually fitted to RP37A VHF Heralds instead of the Celestion. The available data suggests that the Elac was the preferred choice for the VHF Herald, with the Celestion being considered a suitable substitute. When this Elac is used, the amplifier PCB is rotated through 180 degrees. And while I haven't tried it, I suspect that this Elac won't fit in a Sovereign II because of the magnet.

There is another Elac, this time with a smaller Alnico magnet and gold-coloured frame/magnet, which was fitted to RP38A Hunters. Early RP38 Hunters used the later Goodmans, but switched to the Elac fairly early in production - but the earliest Elac examples had a grey painted chassis (the magnet was unpainted). There should be an "Elac" sticker on the side of the magnet, but these frequently fall off. These are 15 ohms.

This Elac reappears in the Sovereign IV and RPC1 sets, only it's 4 ohms now - as a result of switching from 18 to 12 volt operation.

Late Bournemouth production Sovereign (IV) and RPC1 sets had yet another loudspeaker - this time with a ceramic magnet. At this stage, I've not taken a close look at it and can't see who makes it. Although the magnet is generally hidden in most internal photographs, you can recognise it from the frame - there is more metal, and more smaller openings in the basket. I will post a photograph and more details in due course.


5" by 7" Loudspeakers:

The Sovereign III family (Black Knight, Super Sovereign, etc) used a smaller 5 by 7" speaker, which has no identifying labels or markings. Luckily, forum member "safria17" asked Hacker at the time, and they told him that it is was made by Peerless. Having recently seen an advert for Peerless loudspeakers in a magazine from the same time, I can only agree - although the advert showed a range of round speakers, the distinctive magnets confirm this.

I didn't notice until recently that the Super Sovereign uses a version of this loudspeaker with a slightly larger magnet.

4" by 6" Loudspeakers:

Many of the smaller sets used a 4" by 6" loudspeaker - the Mini-Herald, the Autocrat (both versions), the Democrat and the Harrier. The earlier sets used a unit made by Goodmans, which was 25 ohms in the Mini-Herald, and 15 ohms in the Democrat. The later Mini-Herald also used a unit made by Rola-Celestion.

The Mk1 Autocrat also used the Goodmans speaker in 25 ohm form. The same speaker was used in many Dynatron sets of the period.

The Mk2 Autocrat and Harrier used different loudspeakers - these had larger magnets and, reflecting the 9V operation, were 5 ohms. There are two different versions; one painted grey, one gold-coloured like the Elac units. At this stage I'm not sure of the manufacturer, or the significance between the different finishes - still gathering data.

Miscellaneous Loudspeakers:

The Ranger and Aviemore sets used a round loudspeaker, about 4 inches in diameter, and I've seen 3 or 4 variants. In general, earlier sets used larger magnets and sounded better. Various models have been seen, including the infamous plastic Philips model in very late production. A model from Audax with a grey painted frame was popular. Unfortunately, they seem to get worse (cheaper?) as production continued.

Later sets (the Consort RP79, Herald RP82 and Knight RP85) use a 4" by 7" model made by Audax. It's not a patch on the earlier Celestion or Goodmans units, but a welcome upgrade from the round speakers mentioned above.

I think that's pretty comprehensive, and should definitely help when buying or repairing sets. Thanks to everyone who contributed data, and please feel free to continue doing so - remember to include serial numbers and I'll be able to add them to the Hacker group database :)

Thanks again,

Mark :)

Re: Hacker Speaker Survey
 

I have a Sovereign II srl no 14420 with 5"x8" grey Goodmans speaker with 3 round head screws on the unpainted magnet housing.
Incidentally what is the significance of the annotation under the tuning knob (on the pastic dial) Mine is inscribed 'B/25/19'?
Tony

Re: Hacker Speaker Survey
 

Tony,

I think it's the factory drawing and part no.

Yours set is an RP25.

The numbers below the tuning knob on an RP25A are B/25/19A and on an RP25B are B/25/19B. Is your set blue or black?

Regards,

Ian

Re: Hacker Speaker Survey
 

Hi Ian
Its blue and fortunately with all silicon transistors
Tony

Re: Hacker Speaker Survey
 

Hi Tony,

Many thanks for the information. According to the RP25 service manual, the silicon transistors came in around serial number 13001, so that fits. The speaker change happened slightly afterwards; I know of another set with the silicon tuner and bolted speaker - serial number 15301, so everything sounds in order.

Just out of interest, a minor detail of the scale changed sometime around here. Looking at the 3 wide slots through which you observe the pointer, the earlier sets had a white outline around them, whereas the later sets only had a white line at the top of the opening. Which does yours have? (If my description isn't clear, I could post a photo tomorrow.)

Mark

Re: Hacker Speaker Survey
 

Hi Mark
Mine only has the white lines above the slots (not below)
Tony