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Vintage Amateur and Military Radio Amateur/military receivers and transmitters, morse, and any other related vintage comms equipment. |
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2nd May 2019, 5:08 pm | #21 |
Dekatron
Join Date: Feb 2005
Location: St.Ippolyts, Hitchin, Hertfordshire QRA IO91UW
Posts: 3,517
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Re: Pye T470 Transmitter
When I get round to it, I have some aircraft gear here that will put out a decent signal on 2m AM. So yes, please build something so I can work more than one or two stations
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2nd May 2019, 5:24 pm | #22 |
Nonode
Join Date: Nov 2015
Location: Welwyn Garden City, Hertfordshire, UK.
Posts: 2,013
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Re: Pye T470 Transmitter
Haha OK Sean - I'll bring my P5001 to Hitchin so you can have a signal on 144.550!!
Maybe Redcoats is a good spot to work you? Sorry Wendy - I don't think any of my 4m gear will get up your way. I did put an F4001 on 70.26 AM connected to Echolink - it was MB7AM in Amersham. I wouldn't allow connections from any other than individual users. No links conferences or such. It was intended that people could get experience of 4m AM and maybe test their own gear if they were in range of it. Sadly it didn't work for long before the antenna died. Getting that fixed has been impossible for almost 2years now. Put on something similar at your end, far enough away they can't hear one another, could be an awful lot of fun if they could be connected together. It is said a Raspberry Pi can do this - mine was PC based. Last edited by Jon_G4MDC; 2nd May 2019 at 5:30 pm. |
3rd May 2019, 4:54 pm | #23 |
Pentode
Join Date: Jan 2009
Location: Liverpool, Merseyside, UK.
Posts: 149
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Re: Pye T470 Transmitter
Hi
T470 in 3 pages in a zip |
5th May 2019, 5:19 pm | #24 |
Nonode
Join Date: Nov 2015
Location: Welwyn Garden City, Hertfordshire, UK.
Posts: 2,013
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Re: Pye T470 Transmitter
Thanks for the scans - nice to see those circuits again.
It has confirmed crystals around 4MHz needed, as I recalled, though for the narrow deviation needed on 70cm conversion to 12MHz was possible by a rewind of the phase modulator coils and letting the first tripler stage be just a buffer. I think I did that to mine at some point since 12MHz were ex stock and 4MHz would have to be bought with real money. Last edited by Jon_G4MDC; 5th May 2019 at 5:22 pm. Reason: Mr Hertz's capital letter |
7th May 2019, 8:41 am | #25 |
Heptode
Join Date: May 2008
Location: Selby, North Yorkshire, UK.
Posts: 949
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Re: Pye T470 Transmitter
Thanks from me also for the circuit diagrams. I was sure there must be a UHF bandpass yet didnt see it in the set, but also no sign that anything was missing! I think now I know where it is and why i didnt see it.
I also essentially picked this up as a donor. I like the old Pye sets for this as the modular construction lends itself to lots of nice self contained bits for other projects, like a ready built PA or filters. In this case im thinking the reflectometer module might make a handy tool.
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8th May 2019, 8:38 am | #26 |
Nonode
Join Date: Nov 2015
Location: Welwyn Garden City, Hertfordshire, UK.
Posts: 2,013
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Re: Pye T470 Transmitter
Yes - the 70cm bandpass filter is about the size of a packet of 10, slung underside and tuned through the rear panel I think but it will be 1980 or so since last I played with one.
The reflectometer is interesting, as in so many it is after the filter that removes any harmonics. The diodes happily put them all back on again and cause reverse intermod into the bargain if there is any coupling between antennas. The flip side of the other way, of course, is you have to measure match through any filter reflections... |
22nd Jul 2019, 10:24 pm | #27 |
Retired Dormant Member
Join Date: Jan 2008
Location: Dublin, Ireland
Posts: 1
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Re: Pye T470 Transmitter
Hi Ian
Sent you a PM concerning Pye T470 Cheers John. |