Non Directional Beacon receiver used 4.4MHz IF information wanted. - UK Vintage Radio Repair and Restoration Discussion Forum

robinshack · 11th Mar 2023, 5:49 pm

Sorting through a large box of crystals today, I found a few for NDB receiver frequencies from 210KHz to 370KHz. There are can markings between 4030 KHz for 370KHz to 4190KHz for 210KHz.
All are Hc6/u
This gives an IF of 4.4MHz.
Bags were marked as NDB Monitor with the lf frequency of the actual channel.
Any ideas what NDB rx used such an IF.
Picture of the box of crystals. The lever arch files are mostly in correct order by frequency. The rest are not!
Thanks, Rob

Dave757 · 11th Mar 2023, 9:43 pm

Hi Rob,

The only clue seems to be that it would probably be a US or Canadian
design as 210 kHz is not going to be used for beacons in areas with
Long Wave broadcasting.
Coincidentally the only thing I could find with a 4.4MHz IF was a
reference to the Nautel NRB4 beacon receiver (US/Canadian Manufacture),
which does cover 210 kHz but doesn't use crystals!

Kind regards
Dave

robinshack · 12th Mar 2023, 3:45 pm

Thanks Dave.
No worries, just curiosity really.
Won't be any use these days anyway, so will go into the clearout pile.
Thanks, Rob

buggies · 12th Mar 2023, 8:33 pm

Quote:

Originally Posted by Dave757

Hi Rob,

The only clue seems to be that it would probably be a US or Canadian
design as 210 kHz is not going to be used for beacons in areas with
Long Wave broadcasting.

Kind regards
Dave

252kHz was in use when I was flying out of Edinburgh (from about 1990-2014).
There was this message for someone else in PPrune in 2015:-

Quote:

A few years ago the Leuchars NDB on 252 kHz was getting interference from Radio Atlantic. I reported the interference. The initial response was "what NDB", then they discovered it was from days of the Hunter fighter. For decades it had been pumping out a high power for 150 miles range.

Turned out the frequency bands had been reallocated and it had been illegal for years. It was replaced with a low powered 15 Miles range one on a different freq.

turretslug · 12th Mar 2023, 11:21 pm

Two thoughts occur: How much had that cost the taxpayer, and does that mean that users of AM pantry transmitters are reassured of insignificance!

Graham G3ZVT · 13th Mar 2023, 6:27 pm

The anacdote is very interesting, but a bit odd.

During the 90s when A252 was in its heyday, I visited the Kingdom of Fife several times and can distinctly remember that reception was not marvelous, but I have no recollection whatsoever of any interference (other than from the co-channel Algerian station).

11th Mar 2023, 5:49 pm	#1
robinshack Nonode Join Date: Jun 2010 Location: Spalding, Peterborough, Cambridgeshire, UK. Posts: 2,621	Non Directional Beacon receiver used 4.4MHz IF information wanted. Sorting through a large box of crystals today, I found a few for NDB receiver frequencies from 210KHz to 370KHz. There are can markings between 4030 KHz for 370KHz to 4190KHz for 210KHz. All are Hc6/u This gives an IF of 4.4MHz. Bags were marked as NDB Monitor with the lf frequency of the actual channel. Any ideas what NDB rx used such an IF. Picture of the box of crystals. The lever arch files are mostly in correct order by frequency. The rest are not! Thanks, Rob Attached Thumbnails __________________ I am also interested in and collect 00 model railway. My avatar is Bruiser, he has cauliflower ears!

11th Mar 2023, 9:43 pm	#2
Dave757 Heptode Join Date: Apr 2009 Location: Scratby, Norfolk, UK. Posts: 629	Re: Non Directional Beacon receiver used 4.4MHz IF information wanted. Hi Rob, The only clue seems to be that it would probably be a US or Canadian design as 210 kHz is not going to be used for beacons in areas with Long Wave broadcasting. Coincidentally the only thing I could find with a 4.4MHz IF was a reference to the Nautel NRB4 beacon receiver (US/Canadian Manufacture), which does cover 210 kHz but doesn't use crystals! Kind regards Dave

12th Mar 2023, 3:45 pm	#3
robinshack Nonode Join Date: Jun 2010 Location: Spalding, Peterborough, Cambridgeshire, UK. Posts: 2,621	Re: Non Directional Beacon receiver used 4.4MHz IF information wanted. Thanks Dave. No worries, just curiosity really. Won't be any use these days anyway, so will go into the clearout pile. Thanks, Rob __________________ I am also interested in and collect 00 model railway. My avatar is Bruiser, he has cauliflower ears!

12th Mar 2023, 11:21 pm	#5
turretslug Dekatron Join Date: Nov 2011 Location: Surrey, UK. Posts: 4,288	Re: Non Directional Beacon receiver used 4.4MHz IF information wanted. Two thoughts occur: How much had that cost the taxpayer, and does that mean that users of AM pantry transmitters are reassured of insignificance!

13th Mar 2023, 6:27 pm	#6
Graham G3ZVT Dekatron Join Date: May 2010 Location: Greater Manchester, UK. Posts: 18,515	Re: Non Directional Beacon receiver used 4.4MHz IF information wanted. The anacdote is very interesting, but a bit odd. During the 90s when A252 was in its heyday, I visited the Kingdom of Fife several times and can distinctly remember that reception was not marvelous, but I have no recollection whatsoever of any interference (other than from the co-channel Algerian station). __________________ -- Graham. G3ZVT