Trio 9R 59 ( NOT de or ds versions)

[g0hze snowy]

good morning peps, an update on the above radio, it lives!, not well but now workable.
from switches, antenna sockets removed and wires cut to dirty pots, good old detoxit, changed a couple of poor performing bottles we now have sig gen output from the speaker, not very sensitive but an improvement on nothing at all.
It didn't help that the el90 audio valve had its cathode shorted to chassis with the valve retaining spring!.
Now to my question #1, most of the caps are original marked as 0.05mf at 600vw working, advice please on what to substitute them for.
Question #2 is that my geni tone is set at 14mhz but the scale shows a tad over 13mhz, non of the caps, coils ifts have been tweaked by the phantom tweaker, all paint sealing 'splodges' are intact.
so onwards and upwards
TIA
Snowy

[David G4EBT]

I'd make two observations.

Firstly regarding the capacitors, I maybe be mistaken, but I believe that many, if not most, will be disc ceramic capacitors which are very reliable, rather than waxy paper caps which we know in 1940s/50s UK domestic receivers such as the Bush DAC90A and other tend to be 'leaky' in the electrical sense.

If they are disc ceramic, if it was my receiver, I'd leave well alone.

If they're tubular, I'd probably test one or two on an insulation tester at the rated voltage to check if they're leaky. If not, I'd leave them in situ. The capacitor which tends to cause most problems on domestic radios if it's a waxy paper cap type is the audio coupling capacitor, which in your radio is C23.

For 0.05 600V, the current equivalent would be polyester 630VW.

It's your radio, to do as you please with.

Re the tuning seeming to be out, bear in mind that the radio has bandspread as well as band-set tuning. As it's a general coverage receiver, the amateur bands cover only a small segment on each band. Bandspread enables that small segment on each band to be electronically spread on the pre WARC amateur bands of 3.5, 7, 14, 21 and 28 MHz. (10 80, 40, 20, 15 & 10 Metres) - a sort of slow motion tuning device.

The instructions tell you to set the bandspread dial to 100. If not, I guess it could throw the tuning out on the bandset dial. (though it wouldn't vary the main tuning by as much as 1 MHz).

Bear in mind that the manual, though comprehensive, is a Users' Manual with no instructions on how to align the receiver. (There be dragons!).

https://www.rigpix.com/kenwood/trio_9r59_manual.pdf

If you really want an accurate readout of the frequency, best get one of those cheapo Chinese digital counters and set the IF offset on the counter to 455 kHz. Or just enjoy owning and using a nice vintage general coverage receiver of its day, with an RF stage, 'Q' multiplier and BFO.

(I hankered after one when they were new, but couldn't afford one!).

Hope that might help a bit.

[g0hze snowy]

David, that's the most comprehensive advice so far, and yes you are right most of the coupling caps are green disc types, the 2 or 3 caps that i could get to are measuring within spec, not bad for a radio getting on in years, abit like me, 77 turns on my coil as G3JKW would say.
Dont want to make it ultra modern, just get it working well enough to enjoy once in a while.
Perhaps 1 or more of the previous owners knew these dragons and left everything alone ha ha.
Just got some matching knobs turn up today and a couple of bottles as replacements if needed.
Radio Wrangler provided me with a much needed circuit diagram, helped with the correct placement of the cut-off wires.
Just got to get the guess ('S') meter to work now, the zero pot at the back is twitchy, even after cleaning, replacement coming from the far east! nothing available in the UK.
Thanks for your reply once again.
The RigPix link is broken, but no panic got that one from RW

Snowy

[mickm3for]

Hi i have got alignment details no diag might help mick

[g0hze snowy]

Thanks Mick, all paperwork is beneficial, cheers

[g0hze snowy]

Hi All, Is there anybody that can explain the functions of the 'Q' multi in the above radio RX.
What happens is that when switched to the Q multi i get signals, civvie not ham, the variable cap seems to do nothing, but as soon as i switch it out of circuit i lose all signals, dead quiet. I have changed all the bottles for new replacements, all 'R,s' are within value and as it has been pointed the disc ceramics hardly ever fail, even the electrolytic's are within spec.
so can a knowledgeable person please make it simple so this ex rock ape ( that's a old RAF Regiment nco) can comprehend.
As always thanks for the advice

[Sideband]

Q multipliers, at least the simple ones that I've knocked up in the past are really a form of reaction to increase the sensitivity and improve selectivity...a bit like reaction on an old TRF radio where you tune the wanted signal and adjust reaction to the point just before oscillation which brings the signal up. So basically that is what you do. I seem to recall that when I was a keen SWL, my favourite bands were 40 and 20 and I use an outboard Q multiplier on my home-built superhet which made a huge difference to the sensitivity.

Basically tune in the wanted signal then use the Q multiplier to bring the signal up out of the noise adjusting the control as required. If the variable cap is doing nothing...well it should! Maybe it only works under certain conditions. What does the operator manual say?

[frsimen]

The early 9r-59 receivers are the same as the Lafayette HE30. The manual for that has a circuit description and alignment instructions. Note that the Q multiplier doubles up to provide the BFO function as well.

The HE30 manual can be found here:

https://bama.edebris.com/download/la.../he30/he30.pdf

Paula

[g0hze snowy]

Thanks Sideband and Paula, will investigate it further given more hours in the day ha ha.

[Andrew2]

Re the calibration being out, it's worth remembering that this receiver is a single conversion type with the IF at 455 kHz. At 14 MHz the image rejection will be pretty poor so you'll probably hear your sig gen at two frequencies about 910 kHz apart.
A proper alignment will help, but not a lot!

[g0hze snowy]

Hi Andy, thanks for that bit of advice, i have put it away for now and will play with it later. Got lots of problems to sort on it, 1 stage at a time ha ha.