Mystery Telly Identification? - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

Heatercathodeshort · 29th Mar 2020, 2:26 pm

As David has mentioned the AGC circuit is wanting. The first common IF is not vari/u being the good old EF80. Only one vision [EF80] and one sound I.F. [EBF89] stages ] are featured rather than frame grid types such as the EF184. I would have thought the gain dropped off despite the PCC89 in the tuner, long before the limits of the service area were reached.
This may have tempted a twiddle.
As mentioned cross modulation must have been a problem on strong BBC signals and I can't remember how effective the pre set Band 1 gain control actually was.
[The Ultra 17-70 series used a somewhat similar arrangement, another bundle of fun for IF twiddlers..]
It's a great picture, the only one I have ever seen featuring the Philco. Other than that the remainder of the circuit was quite reliable. John.

Tractionist · 30th Mar 2020, 10:10 pm

Hmmm .... my experience of most Philco kit is: 'stylish/modernistic' but tends to be lacking in circuit design and component [and sometimes build] quality. (Not too dissimilar from certain Ecko kit I suppose ...).

Heatercathodeshort · 31st Mar 2020, 9:42 am

The later Philco receivers were like many of this period [1961/63] as you say, all slimline appearance but not a lot of thought gone into longevity. The earlier receivers such as the model 1967 etc were very well made.
I'm surprised at your Ekco comment. I've always considered them to be one of the best even through this uncertain early 60's period.
The equivalent Ekco receiver to the Philco would have been the TP347 series. Chalk and cheese. All water under the bridge now. John.

29th Mar 2020, 2:26 pm	#21
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: Mystery Telly Identification? As David has mentioned the AGC circuit is wanting. The first common IF is not vari/u being the good old EF80. Only one vision [EF80] and one sound I.F. [EBF89] stages ] are featured rather than frame grid types such as the EF184. I would have thought the gain dropped off despite the PCC89 in the tuner, long before the limits of the service area were reached. This may have tempted a twiddle. As mentioned cross modulation must have been a problem on strong BBC signals and I can't remember how effective the pre set Band 1 gain control actually was. [The Ultra 17-70 series used a somewhat similar arrangement, another bundle of fun for IF twiddlers..] It's a great picture, the only one I have ever seen featuring the Philco. Other than that the remainder of the circuit was quite reliable. John.

30th Mar 2020, 10:10 pm	#22
Tractionist Heptode Join Date: Apr 2016 Location: Cheltenham, Gloucestershire, UK. Posts: 875	Re: Mystery Telly Identification? Hmmm .... my experience of most Philco kit is: 'stylish/modernistic' but tends to be lacking in circuit design and component [and sometimes build] quality. (Not too dissimilar from certain Ecko kit I suppose ...). __________________ Red to red, black to black. Throw the switch and stand well back!

31st Mar 2020, 9:42 am	#23
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: Mystery Telly Identification? The later Philco receivers were like many of this period [1961/63] as you say, all slimline appearance but not a lot of thought gone into longevity. The earlier receivers such as the model 1967 etc were very well made. I'm surprised at your Ekco comment. I've always considered them to be one of the best even through this uncertain early 60's period. The equivalent Ekco receiver to the Philco would have been the TP347 series. Chalk and cheese. All water under the bridge now. John.