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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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1st Jun 2018, 9:34 am | #1 |
Triode
Join Date: May 2018
Location: Newmarket, Suffolk, UK.
Posts: 19
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9R-59D calibrator circuit
Apologies for all the bandwidth on this radio but it is nearly finished now.
It will need re-calibration as the main tuning is reading 200khz high on the 40m band, I haven't checked the other bands but I expect they will all need some attention after being devoid of electrons for over 30 years. To me it is a miracle it works at all! Yesterday I ordered one of the QCX 5W CW transceiver kits which beyond its primary function, it has a comprehensive signal generator and frequency counter built in. The SG I think will suffice for re-calibrating the 9R-59D. I want now to add a calibrator circuit to the 9R-59D , but the diagram in all the operations manuals I can find on the web all have a transistor circuit. I read somewhere that early manuals originally had a valve calibrator circuit and since the all holes are there (including the mysterious 3 way barren tag board) I would quite like to keep the radio an all glowing affair. Does anyone have a copy of the early manual with the valve calibrator circuit they could share with me? Thanks! Ted |
1st Jun 2018, 9:35 am | #2 |
Moderator
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,289
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Re: 9R-59D calibrator circuit
I have the info you need. Give me time to scan it and I'll post it here.
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Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
1st Jun 2018, 2:15 pm | #3 |
Moderator
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,289
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Re: 9R-59D calibrator circuit
Here you go.
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Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
1st Jun 2018, 3:47 pm | #4 |
Triode
Join Date: May 2018
Location: Newmarket, Suffolk, UK.
Posts: 19
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Re: 9R-59D calibrator circuit
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1st Jun 2018, 3:52 pm | #5 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,903
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Re: 9R-59D calibrator circuit
You need to be sure you have a large format crystal like in an HC6-U can for a valve oscillator. They tend to run crystals at higher levels than transistor oscillators and can fracture the quartz in modern HC25 and smaller parts.
David
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Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done |
1st Jun 2018, 8:26 pm | #6 |
Heptode
Join Date: Feb 2007
Location: West London, UK.
Posts: 867
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Re: 9R-59D calibrator circuit
I know you want to keep it an "all glowing affair", but less current drain from the mains transformer if you use the transistor circuit.
I have put LED dial lamps in my 9R 59D to give the transformer an easier life. John |
2nd Jun 2018, 2:41 pm | #7 |
Triode
Join Date: May 2018
Location: Newmarket, Suffolk, UK.
Posts: 19
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Re: 9R-59D calibrator circuit
Thank you all for your help on this.
John That never occurred to me! It might explain why they opted for the silicon solution in later manuals. It sounds like you have already determined the power supply is on the edge, did the LED lights make a difference to performance? You probably guessed I am keen to keep this set as original as possible and to be honest it is working pretty well since the dipole went up. If another valve is going to compromise the set, then silicon it will be. David thank you and noted, but given the above, it looks like I will be taking the silicon route. If the PSU is close to running out of puff, it might also explain why the set didn't have the OA2 stabiliser fitted as standard. I speculate... Best Ted |
2nd Jun 2018, 8:40 pm | #8 |
Heptode
Join Date: Feb 2007
Location: West London, UK.
Posts: 867
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Re: 9R-59D calibrator circuit
Aztecboy,
The only difference with the LED's is that they are brighter!. Radio just the same. I have left the lampholders in place and put the good filament lamps in an envelope inside the receiver so I can or someone else can always put it back to original if desired. John |