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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 Mar 2021, 10:28 pm | #1 |
Pentode
Join Date: Mar 2008
Location: Bury, Lancashire, UK.
Posts: 138
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19 set alignment
Hi all
Been looking round lots of sites for 19 set re alignment details, rather than taking apart one of my IF cans does any body know which is the primary or secondary in the can top hole or bottom.Also I have seen two different alignment details conflict ,one says to align the HF band with the oscillator on the high side (which I think is correct) and the other says to set the Osc on the Low side for the HF band, any thoughts .regards Keith. |
5th Mar 2021, 6:54 pm | #2 |
Pentode
Join Date: Mar 2008
Location: Bury, Lancashire, UK.
Posts: 138
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Re: 19 set alignment
Mods please remove nobody,s interested
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5th Mar 2021, 7:02 pm | #3 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,867
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Re: 19 set alignment
Perhaps nobody knows, or maybe the ones that do only look in fairly infrequently. Your post will pop up in their 'new posts' listing when they do. It might be worth leaving it a week or two.
I would assume LO on the high side because it keeps the images out of the more populated bands, but if you try it and find the adjusters run out of range, then that would suggest low side. But I've had little involvement with 19 sets other than the variometers and dynamotors. David
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Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done |
5th Mar 2021, 8:53 pm | #4 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
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Re: 19 set alignment
Not sure if this is relevant but there's a section in RDH4 that explains an advantage that might be had on shortwave by having the oscillator frequency on the low side of the signal frequency when the oscillator injection is to the inner grid (g1) of the mixer.
RDH4, book page 991 (Section 25.2 (ii) B : http://www.tubebooks.org/books/rdh4.pdf Lawrence. |
6th Mar 2021, 9:20 pm | #5 |
Pentode
Join Date: Mar 2008
Location: Bury, Lancashire, UK.
Posts: 138
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Re: 19 set alignment
Hi David /Lawrence
Thanks for the reply I have checked my set and the Osc is on the high side on the higher range 4.5 / 8.0 mc/s although the adjusters are not out of range, I came across some info on the19 set re-alignment stating the HF band Osc should be lower than sig frequency so I think I will leave it as is .regards Keith. |
6th Mar 2021, 9:29 pm | #6 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
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Re: 19 set alignment
Just out of interest, I had a receiver where the oscillator was on the low side of the signal, it was on the highest range of the Marconi CR300.
Lawrence. |
6th Mar 2021, 9:34 pm | #7 |
Pentode
Join Date: Mar 2008
Location: Bury, Lancashire, UK.
Posts: 138
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Re: 19 set alignment
Hi Lawrence
Strange really I would expect the Osc to be higher than the rx signal I think I need to investigate more before delving into the set again, regards Keith. |
6th Mar 2021, 9:42 pm | #8 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
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Re: 19 set alignment
Yes, the oscillator below the signal frequency on the highest band range for the CR300 was by design, it's mentioned in the alignment instructions.
Lawrence. |
6th Mar 2021, 9:42 pm | #9 |
Octode
Join Date: Oct 2008
Location: Littlehampton, West Sussex, UK.
Posts: 1,465
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Re: 19 set alignment
You’ll find 19 set alignment instructions as various EMERs in the vmars manuals website free of charge. The instructions tell you which end of the IF can is which and include a procedure to ascertain whether you have the image on the correct side.
There’s a wealth of free info there for mk2s and mk3s and it’s all in good readable condition. Good luck Jim |
7th Mar 2021, 7:25 pm | #10 |
Pentode
Join Date: Mar 2008
Location: Bury, Lancashire, UK.
Posts: 138
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Re: 19 set alignment
Hi Jim
Thanks for the info I am a member of vmars and I have just reset my brain I think lock down is having a strange affect on me .regards,Keith. |