Pye Trio dual standard.

[6.3volts]

Hi everyone and a happy new year to all.
I'm working on a Pye with what claims to be a 11U chassis. This is dated 1965 and has the later stabilized eht circuit. It also has several variants not covered in either of my service sheets. V6 should be a triode pentode with interference limiter. Instead I have a EF182 with no limiter components anywhere on the board-all factory original. Also there is a 625 line pre-set contrast control which is not shown and the two tuners are switched on and off by the change over switch which again is not covered by my literature Has any one seen these variants before or has someone got better info including variants. Any help or advice would be welcome. I would add that I have the set working reasonably well and am currently try to resolve poor focusing at the corners of the screen and am looking for a bit more contrast and volume on 625.

Jonathan

[Heatercathodeshort]

Hello Jonathan,
I have been involved in fully restoring one of these in the last few months.
You have the later Pye 11U chassis with EF183 and EF184 valves fitted. The earlier version employed the PCF80 in the I.F. Twin contrast contols are fitted in the later version as the user control is high level and does not operate on the AGC rail.
UHF performance is a bit poor due to the use of a valve tuner. The PC86 and PC88 valves may well be low. Take great care when removing/fitting. Components mounted on the valve bases can fracture if treated roughly. Some late receivers were fitted with a transistor UHF tuner and this improved the gain considerably.
For low distorted sound on UHF/625 you will need to tweak L28. The tuning is a sharp dip and only a slight turn will be required. A special hexagon tool is required and any attempt to adjust this with anything else will break the core. Be warned. The reason for the drift is slight shift of the coil on it's former that by now will have stabilized. Do not under any circumstances open the coil can and fiddle or adjust any of the other tuning cores! The F.M. detector is a locked oscillator using the EH90 valve also used in Sobell/GEC receivers. The 11U chassis performs very well and is easy to repair. Regards, John.

[dazzlevision]

Hello,

To uniquely identify your particular Pye TV chassis, you need to know the "RV" number, which is usually stamped on the chassis metalwork somewhere (in ink, not mechanically stamped into the metalwork itself). The RV number for your set will be somewhere in the range RV168 to RV217. It's usually on the central vertical metalwork between the two PCBs or on one of the two top brackets securing the chassis to the cabinet (although it might be different in the Slimline Trio).

According to my records, the Pye model 28 "Slimline Trio" TV/radiogram uses chassis RV217C, which is covered by Pye TV service manual for chassis RV217 & RV218, dated Aug 64 (models 11, 12, 14, 20, 21, 22 & 23 (incl. U & F versions)).

As Heatercathodeshort has said, your "Pye 11U series" chassis is a later version that has several significant mods. Watch out for the line output transformer, it is prone to failure. I would replace all wax caps in the line output stage (including the boost HT decouplers) and the 10nF line drive coupling cap (usually a ceramic printed circuit mounting type - replace with a polyester film type) - before you run the set for, even a short time. Make sure the set is run with minimum boost HT setting, consistent with adequate width.

Regards,

Dazzlevision

[6.3volts]

Thanks for your advice. I've sorted the caps etc and have noted your comments about boost HT.

My chassis is date stamped 1965 and is a type RV230D so postdates your references. I have run the tube on its own with a forward current for several hours to wake it up and it is now giving a reasonable brightness but a slightly 'metallic' picture with poor mid tones. I'm not sure if this is a tube issue or an I.F. problem. I did wonder if a better detector diode might improve mid range sensitivity on the picture - it's the same on both standards.

Regards Jonathan

[Hunts smoothing bomb]

Hello Jonathan,

You say the picture has a slightly metallic look to it? This with the addition of poor focusing in the corners that you mentioned in post #1 would lead me to believe that the CRT emission is low.

I have some sets with low tubes but they come up after a few hours use and are quite watchable.

Cheers

[dazzlevision]

Thanks for your advice. I've sorted the caps etc and have noted your comments about boost ht.
My chassis is date stamped 1965 and is a type RV230D so postdates your references. I have run the tube on its own with a forward current for several hours to wake it up and it is now giving a reasonable brightness but a slightly 'metallic' picture with poor mid tones. I'm not sure if this is a tube issue or an I.F. problem. I did wonder if a better detector diode might improve mid range sensitivity on the picture - it's the same on both standards.
Regards Jonathan

Hello again,

That's interesting. I think the explanation for the difference is that your Pye TV/radiogram has a chassis made in the Ekco works in Southend on Sea, rather than the Pye works in Lowestoft. Following the Pye merger with Ekco in 1960, the two companies designed and produced their own TV chassis until the first "common" TV chassis appeared, starting with the Pye TV11/U and Ekco T418 series, circa 1963.

Having said that, there were still subtle differences between the Pye and Ekco sets, as they still produced separate Pye and Ekco service manuals. This carried on until the Ekco factory was closed and they had one manual for all Pye group brands, starting with the '67 chassis.

So, your set has an Ekco version of the commonly referred to as Pye 11U series chassis and will be covered precisely by the Ekco service manual for the RV230D chassis. However, the Pye RV217C manual should be very close, if that is all you can obtain.

The following Ekco (and Ferranti bbranded version) full manual covers the RV230D chassis:

Ekco models T433, TC435, TC437 and Ferranti models T1121, TC1122, TC1124, & TC1126; Refs. RV230, RV230A, RV231 & RV231A; dated May 64.

Various supplements were issued subsequently to cover newer models with the same basic chassis:-

T434, T436, T1123 & T1125; supplement, RV230A & RV231A (incl. F, T & FT versions), May 64.

T433, T434, TC435, T436, TC437, T1121, TC1122,T1123, TC1124, T1125 & TC1126 (incl. F, FT & T versions) supplement, RV230B & D, RV231B & D, Sep 64.

T443, T1137 & T1139, supplement, RV230D RV231; Mar 65.

T458, T458/1, T459, T459/1, T460 & T460/1, supplement, RV230D RV231E, Aug 65.

T463, T464, T1137/1 & T1139/1, suppl’t, RV230D RV231E, Nov 65.

T464/P (s/no. 21501 onwards), T1152 & T1153, supplement, RV230D & RV231E, (incl. F, T & FT versions), Mar 66.



You can usually ID a Southend or Lowestoft chassis by looking at:

The wiring to the tuners/front controls (solid core and thicker PVC insulation = Pye; stranded core and thinner PVC = Ekco).

Red silk screening (component side) of PCBs with Pye; green with Ekco.

Ekco sets usually have the model number stamped in blue ink on the chassis, usually without the "T" prefix.

Regards,

Dazzlevision