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"FONADEK" for the busy executive in your life...

Started by gpo706, March 20, 2011, 07:39:30 AM

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gpo706

Its a handset amplifier, I can only find nice bakelite examples on the net, this is a later plastic one, probably the last of the series before phones came with all the bells and whistles like speakers and hand free operation.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=260750184772&autorefresh=true

Nice wee gadget to play with, though who knows what kind of handset its meant for, I guess a standard 700 series.

Will let you know when I connect a PP9 battery and it doesn't work!

Note also the Royal warrants on it, don't get me started on those frauds, they couldn't even find any reference to my Dictographs in their so-called "archives".
"now this should take five minutes, where's me screwdriver went now..?"

GG



These types of "telephone amplifiers" were very common through the 1970s, as an affordable alternative to the speakerphones of that era. 

The general principle is that it uses an induction coil next to the receiver to pick up the incoming signal and amplify it via an ordinary transistor amplifier to the loudspeaker.  The handset's transmitter is positioned into an acoustical cavity that attempts to gather up more audio from the person sitting at their desk.  With careful positioning of the main unit and the speaker, you can avoid the feedback from the speaker to the transmitter.  In a quiet room and with you speaking from a couple feet away from the unit, it can be viable as a speakerphone-substitute. 

These units were typically made in Japan and there are variations in the cradle design for different types of handsets depending on the country for which they were intended.  In some cases they don't quite fit.  For example the standard NTT handset from Japan is a bit "wider" than an American G-type handset, and the GPO handset is definitely "longer" than the G-type in the dimension between receiver and transmitter. 

There was also a Dutch version in bakelite, wherein the handset sat atop the unit on a cradle that caused the transmitter and receiver both to face forward toward the person speaking, rather than depending on an acoustical "scoop."  Placing the handset into the cradle depressed a plunger that turned on the unit, and helpfully turned it off when finished, so a forgetful user wouldn't run down their batteries. 

gpo706

#2
GG - I will have to get back to you when it arrives, I assume the "Royal warrants" applied would infer a UK item suitable for a 700 series handset.

If not I'll have to buy another bloody phone to fit it. LOL!

I reckon the silver knob at the RX end is the on/off button on this unit, when you place the handset on it.

PS those two things at the top end are they "induction coils" they look like the stuff you get when you slide off the diaphragm from a 300 series RX.
"now this should take five minutes, where's me screwdriver went now..?"

GG



Yes, that thing at the top with the two coils, is an induction coil pickup.  One more thing: it will pick up hum from nearby fluorescent lights and other things that emit AC hum. 

The on-off switch is probably built into the volume control similarly to a transistor radio. 

The "Royal warrants" may or may not indicate that the device was designed to be suitable for a 700 series handset.  Try various handsets until you find one that fist best in the cradle and produces the best audio in both directions, you never know which might work best.   

gpo706

#4
Came yesterday, didn't have time but to unpack it, weekend off so got to it tonight, it has an "old" style PP9 clip - ie larger than modern PP9 batteries, so off it came and wired through an electrical block terminal to a spare modern PP9 clip-on.

Next a test - held the loudspeaker to the induction coil and voila - audio feedback, so thems both working.

Howlback gets worse as you adjust the volume knob obviously, didn't put it max in case I blew the speaker.

Next I connected my newest bairn, the 8746 ivory to an extension lead to the other side of the room and tried a call, and it works fine, the design has the acoustic scoop for a 700 series handset so it has the lip of the TX resting on the bottom edge of the  scoop.

The volume resistor is a bit crackly when being adjusted at the lower end of the volume but I've found most old mechanical variable resistors are so affected after many a year.

The chrome bit at the top is the on/off button I suspected when you put the RX end of the handset on it.

There is an internal adjuster accessed through a hole below the volume knob, which I have no idea as yet as to what it does, I haven't tweaked with it as yet, I guess another variable resistor for the induction coils?

(DUHHHH - it's wired to the induction coils Scot)!

So works fine, if rather tinny, next I will remove it to another room so I can do a decent test without echo.

The original battery clips are taped into the cavernous battery cavern, so no harm done for a reconvertion to original and they won't get lost.

Anyone have a suggestion for the crackle on the volume resistor, air-spray or maybe a lubricant could make the contacts run better?

Oh yes and the Royal warrants are there, but rather scratched over the years, the left one is HRH the Queen, but right one I can't see the legend under it so will need to decifer the logo.

The superbly grand "FONADEK" logo's are encasuled in clear plastic and subsequently haven't suffered as much as the warrant transfers.

Later...







"now this should take five minutes, where's me screwdriver went now..?"

gpo706

Left logo HRH The Queen, right is HRH The Duke of Edinburgh, (Queen's hubby).

I shall email the delightful Pippa again...



"now this should take five minutes, where's me screwdriver went now..?"

gpo706

Dear Pippa...

"Dear Ms. Dutton,

Can you confirm the warrants granted to the above company, probably late 30's to the late 60's?

I enclose two pictures of a loudspeaking unit for telephones which have both HRH The Queen's and HRH The Duke Of Edinburgh's warrants on them.

Also did you uncover anything more about Dictograph or Telephone Rentals (post 1967) since my last inquiry?

Thanks in advance,

Yours Sincerely,

Scot Fergie"

I await with anticipation...
"now this should take five minutes, where's me screwdriver went now..?"

gpo706

I tried it upstairs on my phone desk - mains hum!

"now this should take five minutes, where's me screwdriver went now..?"

Owain

Quote from: gpo706 on March 28, 2011, 02:46:11 AM
I tried it upstairs on my phone desk - mains hum!



That's why it works on batteries. :D

It probably predates the widespread use of electronic dictation machines. Anyone senior enough to have a Phonodek probably had a shorthand secretary.

gpo706

Dude, you telling me I have get a dictation secretary off the bay now?

More expensive than I thought this gadget.  :)
"now this should take five minutes, where's me screwdriver went now..?"

gpo706

#10
I just got another for the bakelite GPO 164 handset in your life...

This looks like a big heavy metal piece of kit, note the scoop for the 164 TX horn.

http://www.ebay.co.uk/itm/150672639718?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

"This is a 1950s or 1960s Fonadek telephone amplifier. These were used to convert a phone to a handsfree phone in the days before it was legal to connect your own equipment to the phone line. This one is one of the later transistorized versions. It runs on a 9v PP9 Battery (not included). The case is a little battered, and the switch which turns the unit on when the handset is placed on it, is missing. (The switch is a simple single pole make however, which could be replaced by any pushbutton switch)."

Note it only has the chook of Embra's warrant on it, obviously he was more gadget orientated than her Maj!
"now this should take five minutes, where's me screwdriver went now..?"

gpo706

The seller enclosed a single pole switch with it for gratis, top seller.

However there is no aperture in the RX end for his switch, I have been puzzling over this and maybe reckon that the induction coil in the handset RX actually lifts the thin metal diaphragm in the top of the base end and releases the switch underneath?

What do other readers think?

"now this should take five minutes, where's me screwdriver went now..?"

Owain

Quote from: gpo706 on October 16, 2011, 11:26:30 PM
Note it only has the chook of Embra's warrant on it, obviously he was more gadget orientated than her Maj!


I remember reading an article (can't remember where) saying the Duke of E. was rather disillusioned with the outdated set-up at Buck Hice when he married Mrs. Windsor.

As a Navy man he was used to telephoning when he wanted something, not sending for a footman to deliver a message several hours later.

Although the Royal Warrant refers to the Household and not the Royal person himself, I think it quite likely he would have used such an item.

GG



For those of us on the other side of the Atlantic: does the Royal Warrant signify that this specific Fonadek unit was used in the Royal households or offices, or does it signify that some other Fonadek of the same model, was used there, and the general make & model are approved and endorsed? 

Owain

Quote from: GG on October 20, 2011, 05:03:49 AM


For those of us on the other side of the Atlantic: does the Royal Warrant signify that this specific Fonadek unit was used in the Royal households or offices, or does it signify that some other Fonadek of the same model, was used there, and the general make & model are approved and endorsed? 

It signifies that something supplied by the Fonadek company was used in the royal household. It is not a specific or general product endorsement.
http://www.royal.gov.uk/MonarchUK/Symbols/Royalwarrants.aspx