Eddystone 840C receiver. - UK Vintage Radio Repair and Restoration Discussion Forum

John10b · 18th Oct 2023, 1:44 pm

Came across this in collectibles shop, no price on it.
John

G6Tanuki · 18th Oct 2023, 2:11 pm

If it works, it's probably worth around £40-£50.

It's a somewhat basic HF RX, one RF stage, one IF stage, 465KHz IF and no xtal filter so rather 'wide' in the IF (not good for SSB/CW, but OK for broadcast entertainment listening) and also prone to images above 10MHz.

B8-style 100mA valves

Also, no voltage-stabilisation for the local oscillator so on the upper HF bands the RF Gain control shifts the LO by quite a bit...

And it's AC/DC meaning potentially a 'hot' chassis.

[I have its predecessor the 840A here].

John10b · 18th Oct 2023, 2:55 pm

Thank you for your quick reply and technical information.
John

Sideband · 18th Oct 2023, 3:16 pm

Yes it looks quite impressive but the performance is somewhat disappointing. I never got mine to work really well. Acceptable (just) up to about 14Mhz but beyond that....well!

turretslug · 18th Oct 2023, 11:05 pm

A nice tuning drive (and this 'C' model got the clever linearising mechanism that reduces the usual scale cramping at the HF end) and neat, sturdy mechanical detailing let down by rather humdrum electronics. Still, not a bad basic SWL set if it's at the right price, bearing in mind the above caveats and particularly the AC/DC power supply arrangements- check that a previous owner hasn't defeated the chassis-to-case isolation through incorrect re-assembly!

18th Oct 2023, 1:44 pm	#1
John10b Nonode Join Date: Nov 2016 Location: Aberaeron, Ceredigion, Wales, UK. Posts: 2,888	Eddystone 840C receiver. Came across this in collectibles shop, no price on it. John Attached Thumbnails

18th Oct 2023, 2:11 pm	#2
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 14,015	Re: Eddystone receiver. If it works, it's probably worth around £40-£50. It's a somewhat basic HF RX, one RF stage, one IF stage, 465KHz IF and no xtal filter so rather 'wide' in the IF (not good for SSB/CW, but OK for broadcast entertainment listening) and also prone to images above 10MHz. B8-style 100mA valves Also, no voltage-stabilisation for the local oscillator so on the upper HF bands the RF Gain control shifts the LO by quite a bit... And it's AC/DC meaning potentially a 'hot' chassis. [I have its predecessor the 840A here]. __________________ I'm the Operator of my Pocket Calculator. -Kraftwerk.

18th Oct 2023, 2:55 pm	#3
John10b Nonode Join Date: Nov 2016 Location: Aberaeron, Ceredigion, Wales, UK. Posts: 2,888	Re: Eddystone receiver. Thank you for your quick reply and technical information. John

18th Oct 2023, 3:16 pm	#4
Sideband Dekatron Join Date: Oct 2003 Location: Croydon, Surrey, UK. Posts: 7,585	Re: Eddystone receiver. Yes it looks quite impressive but the performance is somewhat disappointing. I never got mine to work really well. Acceptable (just) up to about 14Mhz but beyond that....well! __________________ There are lots of brilliant keyboard players and then there is Rick Wakeman.....

18th Oct 2023, 11:05 pm	#5
turretslug Dekatron Join Date: Nov 2011 Location: Surrey, UK. Posts: 4,400	Re: Eddystone receiver. A nice tuning drive (and this 'C' model got the clever linearising mechanism that reduces the usual scale cramping at the HF end) and neat, sturdy mechanical detailing let down by rather humdrum electronics. Still, not a bad basic SWL set if it's at the right price, bearing in mind the above caveats and particularly the AC/DC power supply arrangements- check that a previous owner hasn't defeated the chassis-to-case isolation through incorrect re-assembly!