Pye Pocketfone. Transistors. - UK Vintage Radio Repair and Restoration Discussion Forum

Pyeman85 · 4th Jan 2014, 2:45 pm

Hi, does anyone have any info on a transistor GM378B. It was used in the 1st local oscillator of early Pye Pocketfone radios. Also another transistor E5103 also used in the same radio. Any info or equivalents gratefully received.

Mikebay · 4th Jan 2014, 4:15 pm

Hello Pyeman85,
Welcome to the forum
E5103 appears to be a Silicon PIN type photo transistor, in a TO18 case
GM378B, nearest I can find is GM378A, which is a VHF low current amplifier, PNP Germanium, Vcb max 20v, Vce max 15v, Veb max 0.3v, Ic 50mA, Pmax 75mW, good for approx 360MHz and Hfe min 20, and manufacturer was Texas. I should imagine yours, with the B suffix is an uprated near equivalent.

majoconz · 5th Jan 2014, 2:56 am

Is that the Pocketfone in the sky blue/grey case that easily converts to the 70cm ham band? A perforated foil antenna as a speaker grill? 9v battery? I have one in the bottom of my bottomless junk box in a lockup somewhere! And THE MANUAL! It's yours for postage if and when I can find it!

Pyeman85 · 6th Jan 2014, 6:53 pm

Thanks for the info gentlemen, however finding something suitable is proving difficult.
I contacted one firm in Lichfield who have some GM378B in the USA.
They wanted £22 each minimum order 5, we'll forget about them I reckon.
With reference the E5106, in cicuit it's only a switch so I wonder if there are any modern alternatives in such a case TO18?

Pyeman85 · 6th Jan 2014, 6:55 pm

Thanks Martin, what would the postage be from NZ ?

Pyeman85 · 6th Jan 2014, 7:21 pm

Thanks for the info, the parts list index in the service manual actually states GM378B.
I tried a 2N918 but that didn't work I can't imagine why. The 1st oscillator runs at around 88Mhz, maybe the Ft of the 918 is too high. I just wanted to find a good cheap alternative, the BF180 and the BF181 are no problem. I repair, re-crystal quite a few of these models but with the crystals running at £15 it takes the sting out of doing the conversion in the first place. Good old Pye, nothing like an obsolete part.

Sean Williams · 6th Jan 2014, 8:30 pm

Try Peter, G3ZVI, of Garex Electronics, He used to supply lots of PYE radio parts, and may well have some old stock laying around.

majoconz · 7th Jan 2014, 12:12 am

Quote:

Originally Posted by Pyeman85

Thanks Martin, what would the postage be from NZ ?

I'll dig it out of the lockup, wrap it and take it up to the PO and find out - although our 'on line' calculator is usually pretty good. Hope you're not in a screaming hurry!

jim_jobe · 8th Jan 2014, 8:36 pm

Quote:

Originally Posted by Pyeman85

I tried a 2N918 but that didn't work I can't imagine why

The 2N918 is an NPN type but I thought the GM378B was PNP?

Pyeman85 · 10th Jan 2014, 4:56 pm

Hi, yes that's correct it is NPN. I couldn't find any info on the GM378B so didn't know which type it was, the 2N918 was a shot in the dark. No damage done anyway I have the set working again used a 378 from a scrap set.
I was hoping that there would be a cheap alternative so I could hold stock. Not to be I'm afraid, the ex-pmr conversion days are fast fading given the price of crystals and the fact that not everyone has the knowledge or equipment to re-align receivers and transmitters. The cheap Chinese market seems to be booming, Boafeng etc do a synthesized 16 channel handheld with CTCSS for £20. I have one and I have to say it's fantastic, extremely sensitive.

Pyeman85 · 14th Jan 2014, 7:42 pm

After further investigations to find a replacement for the GM378B I came across the AF106. It too is a Germanium PNP in a TO72 case.
I ordered a few from Germany and they arrived within a week. Next thing to do was to remove a genuine GM378B from a working PF1 set and replace it with the AF106. This I did and I switched the set on to hear the phut phut phut of the battery economiser circuit so it appears that the AF106 is a good replacement for the GM378B. All of the receiver stages have to work for the economiser to work. The PF1 I used was an original model crystaled for 452.750Mhz, I popped that frequency into my Marconi 2022 at around 10uV and after the smallest retune the receiver sprang to life. Thanks for your input gents an interesting topic and a good ending. I wish finding a replacement for the E5103 was as easy !!

Pyeman85 · 28th Mar 2015, 4:48 pm

Further to the GM378B transistor, I was on ebay and typed the number in and a listing appeared for NOS GM378B. I nearly fell off my chair, I contacted the guy who said he had hundreds so I struck a deal with him and now I have a good few spares. Happy days

camtechman · 1st Apr 2015, 5:25 am

Quote:

I was on ebay and typed the number in and a listing appeared for NOS GM378B. I nearly fell off my chair

Synchronicity at work !

Even Jung & Freud had to conceed that they could not dismiss it!

boiss · 6th Apr 2015, 11:40 pm

I have a flexible antenna which might have been used on these radios, it is marked 68/78 MHz. I've been trying to identify the antenna connector, it seems to be a sort of male FME?? Any info on the Pye antenna connectors?

G6Tanuki · 7th Apr 2015, 9:21 am

Sounds like the antenna for the "Pocketfone-70" or "PF2" range. Black plastic-cased beasties with a battery-pack that fits inthe nack held in with a T-shaped screw-in thing.

The antenna connection is whats known as a "Mini TNC".

4th Jan 2014, 2:45 pm	#1
Pyeman85 Retired Dormant Member Join Date: Oct 2013 Location: Shrewsbury, Shropshire, UK. Posts: 9	Pye Pocketfone. Transistors. Hi, does anyone have any info on a transistor GM378B. It was used in the 1st local oscillator of early Pye Pocketfone radios. Also another transistor E5103 also used in the same radio. Any info or equivalents gratefully received.

4th Jan 2014, 4:15 pm	#2
Mikebay Rest in Peace Join Date: Nov 2006 Location: Leominster, Herefordshire Posts: 174	Re: Pye Pocketfone Hello Pyeman85, Welcome to the forum E5103 appears to be a Silicon PIN type photo transistor, in a TO18 case GM378B, nearest I can find is GM378A, which is a VHF low current amplifier, PNP Germanium, Vcb max 20v, Vce max 15v, Veb max 0.3v, Ic 50mA, Pmax 75mW, good for approx 360MHz and Hfe min 20, and manufacturer was Texas. I should imagine yours, with the B suffix is an uprated near equivalent.

5th Jan 2014, 2:56 am	#3
majoconz Heptode Join Date: Jan 2008 Location: Ashhurst, Manawatu, New Zealand Posts: 571	Re: Pye Pocketfone. Transistors. Is that the Pocketfone in the sky blue/grey case that easily converts to the 70cm ham band? A perforated foil antenna as a speaker grill? 9v battery? I have one in the bottom of my bottomless junk box in a lockup somewhere! And THE MANUAL! It's yours for postage if and when I can find it! __________________ Cheers - Martin ZL2MC

6th Jan 2014, 6:53 pm	#4
Pyeman85 Retired Dormant Member Join Date: Oct 2013 Location: Shrewsbury, Shropshire, UK. Posts: 9	Re: Pye Pocketfone. Transistors. Thanks for the info gentlemen, however finding something suitable is proving difficult. I contacted one firm in Lichfield who have some GM378B in the USA. They wanted £22 each minimum order 5, we'll forget about them I reckon. With reference the E5106, in cicuit it's only a switch so I wonder if there are any modern alternatives in such a case TO18?

6th Jan 2014, 6:55 pm	#5
Pyeman85 Retired Dormant Member Join Date: Oct 2013 Location: Shrewsbury, Shropshire, UK. Posts: 9	Re: Pye Pocketfone. Transistors. Thanks Martin, what would the postage be from NZ ?

6th Jan 2014, 7:21 pm	#6
Pyeman85 Retired Dormant Member Join Date: Oct 2013 Location: Shrewsbury, Shropshire, UK. Posts: 9	Re: Pye Pocketfone Thanks for the info, the parts list index in the service manual actually states GM378B. I tried a 2N918 but that didn't work I can't imagine why. The 1st oscillator runs at around 88Mhz, maybe the Ft of the 918 is too high. I just wanted to find a good cheap alternative, the BF180 and the BF181 are no problem. I repair, re-crystal quite a few of these models but with the crystals running at £15 it takes the sting out of doing the conversion in the first place. Good old Pye, nothing like an obsolete part.

6th Jan 2014, 8:30 pm	#7
Sean Williams Dekatron Join Date: Feb 2005 Location: St.Ippolyts, Hitchin, Hertfordshire QRA IO91UW Posts: 3,518	Re: Pye Pocketfone. Transistors. Try Peter, G3ZVI, of Garex Electronics, He used to supply lots of PYE radio parts, and may well have some old stock laying around. __________________ Engineers make things work and have spare bits when finished

10th Jan 2014, 4:56 pm	#10
Pyeman85 Retired Dormant Member Join Date: Oct 2013 Location: Shrewsbury, Shropshire, UK. Posts: 9	Re: Pye Pocketfone Hi, yes that's correct it is NPN. I couldn't find any info on the GM378B so didn't know which type it was, the 2N918 was a shot in the dark. No damage done anyway I have the set working again used a 378 from a scrap set. I was hoping that there would be a cheap alternative so I could hold stock. Not to be I'm afraid, the ex-pmr conversion days are fast fading given the price of crystals and the fact that not everyone has the knowledge or equipment to re-align receivers and transmitters. The cheap Chinese market seems to be booming, Boafeng etc do a synthesized 16 channel handheld with CTCSS for £20. I have one and I have to say it's fantastic, extremely sensitive.

14th Jan 2014, 7:42 pm	#11
Pyeman85 Retired Dormant Member Join Date: Oct 2013 Location: Shrewsbury, Shropshire, UK. Posts: 9	Re: Pye Pocketfone After further investigations to find a replacement for the GM378B I came across the AF106. It too is a Germanium PNP in a TO72 case. I ordered a few from Germany and they arrived within a week. Next thing to do was to remove a genuine GM378B from a working PF1 set and replace it with the AF106. This I did and I switched the set on to hear the phut phut phut of the battery economiser circuit so it appears that the AF106 is a good replacement for the GM378B. All of the receiver stages have to work for the economiser to work. The PF1 I used was an original model crystaled for 452.750Mhz, I popped that frequency into my Marconi 2022 at around 10uV and after the smallest retune the receiver sprang to life. Thanks for your input gents an interesting topic and a good ending. I wish finding a replacement for the E5103 was as easy !!

28th Mar 2015, 4:48 pm	#12
Pyeman85 Retired Dormant Member Join Date: Oct 2013 Location: Shrewsbury, Shropshire, UK. Posts: 9	Re: Pye Pocketfone. Transistors. Further to the GM378B transistor, I was on ebay and typed the number in and a listing appeared for NOS GM378B. I nearly fell off my chair, I contacted the guy who said he had hundreds so I struck a deal with him and now I have a good few spares. Happy days

6th Apr 2015, 11:40 pm	#14
boiss Pentode Join Date: Jun 2006 Location: Malaga, Spain. Posts: 235	Re: Pye Pocketfone. Transistors. I have a flexible antenna which might have been used on these radios, it is marked 68/78 MHz. I've been trying to identify the antenna connector, it seems to be a sort of male FME?? Any info on the Pye antenna connectors?

7th Apr 2015, 9:21 am	#15
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 14,007	Re: Pye Pocketfone. Transistors. Sounds like the antenna for the "Pocketfone-70" or "PF2" range. Black plastic-cased beasties with a battery-pack that fits inthe nack held in with a T-shaped screw-in thing. The antenna connection is whats known as a "Mini TNC".