UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > General Vintage Technology > Components and Circuits

Notices

Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets.

Closed Thread
 
Thread Tools
Old 17th Jul 2017, 7:35 pm   #41
Nickthedentist
Dekatron
 
Nickthedentist's Avatar
 
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,723
Default Re: FM to AM Converter?

Brilliant, David, that will be very helpful when I eventually get time to build one.
Nickthedentist is online now  
Old 17th Jul 2017, 8:03 pm   #42
David G4EBT
Dekatron
 
David G4EBT's Avatar
 
Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 5,690
Default Re: FM to AM Converter?

Thanks Nick!

To avoid and confusions with pinouts for the BC184 & BC184L, I've attached a diagram of each.

The PCB layout I drew shows a BC184, so if a BC184L is used, the leads will need to be twisted to suit.

Thanks to Symon for noting this.
Attached Thumbnails
Click image for larger version

Name:	BC184 & BC184L Pinout differences.png
Views:	793
Size:	54.4 KB
ID:	146358  
__________________
David.
BVWS Member.
G-QRP Club member 1339.
David G4EBT is offline  
Old 19th Jul 2017, 3:29 pm   #43
David G4EBT
Dekatron
 
David G4EBT's Avatar
 
Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 5,690
Default Re: FM to AM Converter?

In view of the fact that the designer of the project specified a BC184L rather than a BC184, I've now modified the PCB artwork layout to accommodate a BC184L. For anyone who has etched a PCB for the earlier layout, as I said post #42, a BC184L can be used so long as the wires are correctly located. I've put two negative and two positive masks on the page in case anyone is using a printer which doesn't print a completely opaque mask onto the acetate, so that the acetates can be 'doubled up' to increase opacity.

Hope that might prove useful to any prospective constructors.

Happy to email the artwork to anyone who would like it.

(I've got all the bits, kindly donated by John '60 oldjohn' but have yet to build mine due to other distractions).
Attached Thumbnails
Click image for larger version

Name:	BC184L Version PCB Artwork Neg & Pos_edited-4.jpg
Views:	240
Size:	60.5 KB
ID:	146455   Click image for larger version

Name:	PCB Amendnment for BC184L pinouts.jpg
Views:	330
Size:	67.3 KB
ID:	146456  
__________________
David.
BVWS Member.
G-QRP Club member 1339.
David G4EBT is offline  
Old 23rd Jul 2017, 11:53 am   #44
David G4EBT
Dekatron
 
David G4EBT's Avatar
 
Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 5,690
Default Re: FM to AM Converter?

Just a little update on mounting the FM Module.

There were several aspects of this neat little project that I wasn't too keen about which led me to design a PCB.

Firstly, I'm not a fan of strip-board,( though admittedly it has many advantages over PCBs for one off projects with a low component count, especially when most constructors don't have PCB facilities). Secondly, the strip-board layout had several wire links and needed tracks to be cut in places, increasing the scope for errors. Lastly, the rather strange 'notched' connections of the FM module aren't the same 0.1" (2.4mm) pitch as strip-board, albeit they're not too far out. Mounting of the module on strip-board leaves something to be desired, albeit it can, and has, been successfully achieved by the designer and many others using wires soldered to the strip-board and the notches of the module. It's not the end of the world if anyone writes off a module - ten for £3.00 post free from China, or about £2.00 each in the UK, so no dramas, just a bit of hassle.

I've mentioned in earlier posts that my aim was to design the PCB layout so that Veropins can be inserted into the board to allow the FM module notches to line up with the pins, making soldering to the module much easier and less 'hit and miss' .

Veropins have circular heads to fit circular pads which have good clearance from other pads and tracks. Hence, they don't lend themselves to being fitted into I.C type pads as the heads touch each other. I've therefore ground the heads down to a profile that neatly fits IC pads and have attached some pics to show the underside and upperside of the PCB to illustrate the pins and the FM module in place before soldering, along with a sketch to show what I mean about the heads of the pins. It only takes a few seconds using a Dremel with a grinding disc to make two 'flats' on the heads of the pins. I cut the pins down to 5mm to allow the module to slip down the pins to rest on the board.

Still haven't had time to built it!

Hope that's of interest and use.

I regret that due to time constraints and other commitments I'm not in a position to supply PCBs, but I hope that the info provided in this thread might encourage others to have a go. For those not equipped for UV PCB production there are simpler methods such as the laser printer toner-transfer 'iron on' technique, and 'Press 'n Peel'. I've never tried such techniques but there are countless videos on youtube illustrating how it's done, such as this one:

https://www.bing.com/videos/search?q...13C9&FORM=VIRE
Attached Thumbnails
Click image for larger version

Name:	VEROPINS FOR MOUNTING FM MODULE.jpg
Views:	257
Size:	52.8 KB
ID:	146683   Click image for larger version

Name:	Veropins in board_edited-1.jpg
Views:	259
Size:	33.8 KB
ID:	146684   Click image for larger version

Name:	FM Module on Veropins.jpg
Views:	306
Size:	31.5 KB
ID:	146685  
__________________
David.
BVWS Member.
G-QRP Club member 1339.
David G4EBT is offline  
Old 30th Jul 2017, 10:58 am   #45
David G4EBT
Dekatron
 
David G4EBT's Avatar
 
Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 5,690
Default Re: FM to AM Converter?

Just a little update on this.

Whatever method of construction used - strip-board or PCB - the 'critical success factor' is the mounting of the FM module, due to its unorthodox termination points, (which don't conform to 2.5mm spacing either). That's why - to maximise the prospect of successfully soldering the notched solder termination points - I decided to mount the module on veropins. This enables the module to be held in place on the pins whilst soldering. The third pic in post #44 shows the module in place prior to soldering.

However, this was not a success and the converter failed to work due to unsound soldered connections. The prime reason for that is that the modules are of course designed for commercial SMD production, hence, the solder pads are on the underside of the module, as shown in the first pic below. There are no solder pads to speak of on the top of the module, so with this in mind, it occurred to me that it would make more sense to insert the veropins from the top of the PCB and to mount the module 'upside down' on the underside of the PCB so that the solder pads are visible and can be soldered to the pins.

I therefore scrapped the first PCB and made another, this time with the module on the underside. Happy to report that this was a success and the converter works really well. As to alignment it peaks at 830 kHz (360M) rather than 950kHz (315M) indicated in the article, but that's of no consequence. The 3 - 30 pF trimmer doesn't shift the frequency more than a few kHz and I guess that if desired, to move the frequency up would require that the parallel capacitor C5, would need to be reduced in value.

Pic 1: Underside of FM module showing notched solder pads.
Pic 2: Top of PCB showing the ten Veropins inserted from the top on which to mound the module beneath the board.
Pic 3: Underside of PCB showing the module solder pads successfully soldered to Veropins, (the Veropins having first been soldered to the PCB pads).
Pic 4: Updated positive and negative PCB masks with slightly larger pads for the momentary switch, to allow for a range of suitable switches.
Also, the spacing of the Veropins has been altered slightly to more accurately match the notched terminations of the module for a snug fit.

Happy to email the artwork on request by PM from forum members.

Next task is to box up the module and make a decal along the lines of the original.

Hope that's of interest.
Attached Thumbnails
Click image for larger version

Name:	FM Module Underside_edited-2.jpg
Views:	263
Size:	52.8 KB
ID:	147066   Click image for larger version

Name:	Top of PCB with FM module mounted on the underside.jpg
Views:	323
Size:	37.9 KB
ID:	147067   Click image for larger version

Name:	Module soldered to pins on underside.jpg
Views:	498
Size:	50.4 KB
ID:	147068   Click image for larger version

Name:	AM FM Converter BC184L Version Pos & Neg PCB Mask_edited-1.jpg
Views:	276
Size:	50.1 KB
ID:	147069  
__________________
David.
BVWS Member.
G-QRP Club member 1339.
David G4EBT is offline  
Old 30th Jul 2017, 2:20 pm   #46
ColinB
Heptode
 
ColinB's Avatar
 
Join Date: Apr 2003
Location: Newton Abbot, Devon, UK.
Posts: 757
Default Re: FM to AM Converter?

Does anyone have the source code for the PIC?

It should be simple to remove the 2Hr time limit, and maybe add any other desired features.
ColinB is offline  
Old 30th Jul 2017, 2:46 pm   #47
G0HZU_JMR
Dekatron
 
Join Date: Sep 2010
Location: Cheltenham, Gloucestershire, UK.
Posts: 3,077
Default Re: FM to AM Converter?

Yes, I was tempted to suggest someone makes this an open source alternative to the original. The FM chip does look to be very versatile. If you started again with a PIC or AVR that had more pins then it would be possible to add an LCD display option with frequency readout for a couple of quid (ebay) and a few advanced options like memory, tuning step sizes, tuning speed and received signal strength indicator on the LCD as well. All for the cost of a £2 LCD display and a few more buttons.

But the original design is quite elegant as it stands if you are prepared to scan and save to your favourite FM station and just use it like it is. I'm not sure what the distortion performance is going to be like with that basic modulator but the feedback on here suggests it is adequate for the job. I'd be tempted to use a better modulator circuit but the original design is already OK for some users.
__________________
Regards, Jeremy G0HZU
G0HZU_JMR is offline  
Old 2nd Aug 2017, 4:58 pm   #48
usradcoll1
Heptode
 
Join Date: Mar 2017
Location: Cedar Grove, Wisconsin, USA.
Posts: 823
Thumbs up Re: FM to AM Converter?

Quote:
Originally Posted by Argus25 View Post
I thought I would add to this thread, in case people don't know about these. I only discovered them a couple of years back. There is an excellent quality vintage FM to AM converter made by Audiovox and they are readily available on ebay. They have a super high quality continuous tuning FM tuner made in the typical analog design of the 1970's and 80's FM car radios. They put the received FM stations up on an AM 1400Khz signal (or thereabouts) to feed an AM car radio. Their output simply plugs in series with the antenna wire to the AM radio. They are super compact maybe about 5" by 1". I have attached a photo, and one that was installed in a Triumph TR4 to see the relative size of it compared with an AM radio. It is hard to beat the continuously tunable FM receiver.They can of course be used with any AM radio.
I just bought one at a yard sale for $1.00. I use mine on the large console radios I have in my collection, as there's not much in the line of music on AM here. They work well on a 12V 200ma wall wort AC adaptor.
usradcoll1 is offline  
Old 3rd Aug 2017, 9:08 pm   #49
David G4EBT
Dekatron
 
David G4EBT's Avatar
 
Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 5,690
Default Re: FM to AM Converter?

Further to post #45, I've now boxed up the converter and fitted the waterslide transfer to the front of the ABS box (which is approx. 7cms x 12 cms x 3cms deep). Rather than have the FM & AM aerials as trailing wires per the BVWS Bulletin article, instead, I fitted two miniature sockets at the end of the box as can be seen in the pics below. I terminated the end of the AM aerial with a wander plug so I have the option of plugging it directly into the aerial socket of my Ecko A22 on which I'll be using it, or on an AC/DC radio with no external aerial socket, I can just drape it neat to the set.

All in all, a nice little project which works very will, with no distortion.

Hope that's of interest.
Attached Thumbnails
Click image for larger version

Name:	Inside View end on.jpg
Views:	323
Size:	41.0 KB
ID:	147312   Click image for larger version

Name:	Inside View.jpg
Views:	332
Size:	35.0 KB
ID:	147313   Click image for larger version

Name:	Exrternal view.jpg
Views:	366
Size:	50.0 KB
ID:	147314  
__________________
David.
BVWS Member.
G-QRP Club member 1339.
David G4EBT is offline  
Old 3rd Aug 2017, 11:00 pm   #50
60 oldjohn
Dekatron
 
Join Date: Dec 2004
Location: East Yorkshire, UK.
Posts: 3,917
Default Re: FM to AM Converter?

Hi David, Yet another project very nicely finished off to your high standards, put mine to shame.


John.
60 oldjohn is offline  
Old 4th Aug 2017, 7:37 am   #51
Kevin Hoyland
Heptode
 
Join Date: Feb 2009
Location: Rotherham, South Yorkshire, UK.
Posts: 558
Default Re: FM to AM Converter?

Morning David.
Outstanding work as you always do.

Kevin
Kevin Hoyland is offline  
Old 4th Aug 2017, 7:57 am   #52
David G4EBT
Dekatron
 
David G4EBT's Avatar
 
Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 5,690
Default Re: FM to AM Converter?

Thanks for reading and for your kind comments Kevin.
__________________
David.
BVWS Member.
G-QRP Club member 1339.
David G4EBT is offline  
Old 8th Aug 2017, 7:07 pm   #53
David G4EBT
Dekatron
 
David G4EBT's Avatar
 
Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 5,690
Default Re: FM to AM Converter?

Quote:
Originally Posted by David G4EBT View Post
Just a little update on this.

Pic 1: Underside of FM module showing notched solder pads.

Hope that's of interest.
I've just noticed that pins 6 - 10 in the diagram are numbered wrong, in that pin 6 should be opposite pin5 and pin 10 opposite pin 1 - not as shown in pic 1 of post #45 above. Hence, I've updated the diagram with the pins correctly annotated as shown in the pic below.

Apologies for any confusion.

Amazing little FM modules at just 40pence each post free (five for £1.25) from the Orient, so if one gets trashed while soldering, it's no great drama.
Attached Thumbnails
Click image for larger version

Name:	FM Module Underside_edited-2.jpg
Views:	204
Size:	125.6 KB
ID:	147548  
__________________
David.
BVWS Member.
G-QRP Club member 1339.
David G4EBT is offline  
Old 3rd Sep 2017, 3:24 pm   #54
__i4cy__
Tetrode
 
Join Date: Mar 2015
Location: London, UK.
Posts: 61
Default Re: FM to AM Converter?

Really great to see that many of the FM to AM converters have now been successfully built and are reported to work very well. The finished converters presented in this post appear to be built to a high standard, and in some cases are works of art. But the popularity of the project I believe is due to its constructional simplicity without the need for specialist test alignment equipment.

To respond to and hopefully answer some of the points raised so far in this post.

1. On/Off Switch - There are concerns that 20uA standby current will eventually run down the batteries when not in use for long periods. It is of course possible to insert a switch in series with the battery supply to act as an on/off switch, without having any detrimental effects on the PIC. As long as the default station has been set, the converter will auto tune to the default station when the power is restored.

2. Standby - Another button function that was not mentioned in the original article, is the ability to place the converter into standby before the 2 hour auto switch off period. This is simply performed by de-pressing the button for about 30 seconds at which point the converter will turn off.

3. Copper Cuts - To keep the construction simple and to minimise mistakes, there are only 9 veroboard (stripboard) copper tracks to be cut. These are the tracks between the adjacent PIC and module pins. Though using David's PCB will simplify matters further.

4. Distortion - The simple single transistor AM basic modulator design is a compromise, but it requires no alignment and the components are available and cheap. The converter will indeed exhibit some distortion due to phase noise inherent in this design. But during tests the THD figure was surprisingly very good, and it was considered suitable for general vintage AM receivers which are often Lo-fi anyway.

5. AM Power - The AM power output was calculated to be about 1mW. This along with the highly inefficient AM aerial means very little effective radiated power will be produced. As already mentioned, the received signal drops away significantly after just a few feet.

Many thanks for your support and for having such faith in the project.
Guy
__i4cy__ is offline  
Old 8th Sep 2017, 5:52 pm   #55
David G4EBT
Dekatron
 
David G4EBT's Avatar
 
Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 5,690
Default Re: FM to AM Converter?

Thanks for the helpful feedback Guy, and of course for conceiving the converter in the first place and publishing it in the Bulletin - it's a really natty little gizmo! Useful to know that if need be, it can be put to standby before two hours have elapsed. Mine has been in use now for almost six weeks now, used most days for an hour or so and works a treat through my Ekco A22. To my ears the audio quality is excellent, with no sign of distortion. It's still on its first pair of AA cells - out of curiosity I've just checked the Voltage and it's only dropped to 2.8V. Current consumption of mine is 22mA when in use, and 22µA, when on standby, so an on/off switch is hardly necessary.

I really enjoyed building it, and have started another one to give to a chum. (Just ordered a second PIC!). I only designed a PCB for it because its a facet of the hobby that I enjoy, but few constructors will be geared up for making PCBs, and given that the component count is low, it lends itself to strip-board anyway. Whatever method of construction is used, the trickiest part is mounting the remarkable little FM module, but they're so cheap that it's no big deal if one is trashed. It's evident that quite a few have been successfully built, so numerous constructors have risen to the challenge of soldering the module.
__________________
David.
BVWS Member.
G-QRP Club member 1339.
David G4EBT is offline  
Old 16th Sep 2017, 12:18 am   #56
mictester
Triode
 
mictester's Avatar
 
Join Date: Dec 2007
Location: Sometimes Suffolk and other times Limburg, NL
Posts: 37
Default Re: FM to AM Converter?

Quote:
Originally Posted by Philips210 View Post
Any thoughts on members' experience of the PICKit 3?
I use the PICKit 3 all the time. I write a lot of PICs for all sorts of products. The PICKit 3 is an excellent development system. The software provided by Microchip is excellent. I use my PICKit 3 under Linux, using the USBPICProg software.
mictester is offline  
Old 24th Nov 2017, 12:26 pm   #57
David G4EBT
Dekatron
 
David G4EBT's Avatar
 
Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 5,690
Default Re: FM to AM Converter?

In my earlier post, 8 September, I wrote:

Quote:
Originally Posted by David G4EBT View Post

I really enjoyed building it, and have started another one to give to a chum. (Just ordered a second PIC!).
Well I've finally got round to completing the second one, and as with the first, I'm truly impressed with its performance.

I used the same value of components, but whereas the first one came out at 830kHz, (360M), this one came out nearer to 1 MHz (290M), which was fine at this location, with no interfering stations. The 3-30pf trimmer does shift the frequency, but not to a large degree, so if need be, to lower the frequency to a clear spot on the dial, either a larger value trimmer would be needed or an addition capacitor soldered across the trimmer. (As I recall, '60oldjohn' had to do this).

I built the first one in an ABS project box bought from Spalding Rally, of a size that Maplin used to sell but no longer do. It was just the right size - 12cms x 7cms x 3.5cms (external). I thought it would be easy enough to find such a size from other suppliers/ebay, but no such luck - those on offer from the myriad sizes available were anything but, so out came the comb-joint jig and I made a little wooden box, the size of which was dictated by the size of the front panel, which came out at 7.5cms x 13.5cms.

I designed a water-slide transfer, printed onto white decal paper, allowing for screws at the corner to fix the panel to the box. The external dimensions of the box are 8.5cms x 15 cms x 5cms. For the front panel, I used a piece of scrap double-sided FR4 PCB laminate and mounted the circuit board on 6BA 12mm long stand-off pillars, fitted with 6BA C/S screws, recessed into the front panel. After tightening the screws, I soldered the pillars to the rear of the front panel to stop them coming loose. I filled the heads of the screws so there were no indentations to show through the transfer, painted the front panel white, then applied the transfer.

I've explained before, that when applying water-slide transfers, never slide the transfer off the backing paper or you'll crinkle it up and it will be useless. Always place the transfer more or less where it needs to be applied, and gently slide the backing paper from beneath the transfer as you smooth the transfer into position, taking care not to stretch it. It helps if you wet the panel a little with soapy water. (I always print more than one transfer in case of mishaps).

I fitted two sockets into which to plug in the AM & FM aerials (only two 30cm lengths of wire, one red, one black), but the aerial wires can just be brought out through small holes in the box if desired.

The heart of the converter is the remarkable RDA5807SP FM module - a tiny SMD chip, mounted on a small PCB with just a small crystal and a handful of SMD Rs & Cs. As mentioned earlier, because the PCB is intended to be surface mounted, the small solder pads (ten) are on the underside. The spacing of the notches on the PCB don't exactly conform to the 2.5mm spacing of conventional DIL ICs or strip-board. I guess most people will not want to go to the hassle of a PCB and mounting the module on pins, and will use the simple strip-board layout conceived by Guy Fernando (forum member i4cy). It's rather tricky to solder wires to the module, but others have done it with care. The worst thing that can happen is they you destroy the module, but at a little over £3.00 for ten post-free from the Orient, that's really no big deal.

For those who might wish to know, here is a quote of the technical details of the remarkable RD5805SP chip:

8-<

The RDA5807SP is a single-chip broadcast FM stereo radio tuner with fully integrated synthesizer, IF selectivity and MPX decoder.
The tuner uses the CMOS process, support multi-interface and require the least external component.
The package size is SOP16. It is completely adjustment-free. All these make it very suitable for portable devices.
The RDA5807SP has a powerful low-IF digital audio processor, this make it have optimum sound quality with varying reception conditions.
The RDA5807SP can be tuned to the worldwide frequency band.

8-<

How clever is that!

The datasheet is here:

https://www.elechouse.com/elechouse/.../RDA5807SP.pdf

The converter requires a pre-programmed 8-pin PIC which Guy Fernando is able to supply, currently for £12.95 including P&P, signed for Royal Mail. This can be obtained from Guy at this link, where the full construction details are available, with a much clearer strip-board layout and circuit than appeared in the BVWS Summer Bulletin:

http://www.i4cy.com/M0oox/fm2am

The only other items that may pose a problem as the two small chokes (which look like resistors). One is 150µH, the other is 1mH. These are widely and cheaply available on e-bay. Also, the 6mm green miniature 3-30pF trimmer cap. Again, these are easily found on e-bay. (I bought mine from Spiratronics e-bay shop). The only colour we’re interested in here is green, but for those who don’t know, this style trimmer is colour coded to indicate their capacity as follows:

Blue: 5pF
White: 10pF
Red: 20pF
Green: 30pF
Yellow: 40pF
Violet: 60pF (This colour is a bit variable, but basically, if it isn’t any of the other four colours, it’s this one!)

The push-button momentary switches complete with knobs can also be found cheaply on e-bay.

Both of the converters I've made worked straight off. To find the converter on the dial, I pressed the button to turn it on the tuned across the dial from about 800kHz to 1 MHz till I heard a station. This is easier to do if the radio doesn't have a built in aerial as the converter stations will be the only ones heard, but if there are other stations and you're not sure the one that you have tuned in is from the converter, just press the button to see if the station changes. If so, you've found the converter - if not, keep looking till you do! You can tweak the trimmer for optimal signal.

At this location I can receive 12 FM stations and the audio is excellent quality. A neat way to obtain FM functionality on an AM receiver without any meddling with the radio, keeping it original.

The pictures below are:

Pic 1: Inside view of this second converter, showing the mounting of the PCB on stand-off pillars.
Pic 2: An angled view of the completed converter.
Pic 3: Front view.
Pic 4: Front panel with four C/S 6BA PCB mounting screws recessed, filled, and the panel sprayed white.
Pic 5: Front panel water-slide transfer artwork, printed onto white ink-jet water-slide decal paper (sprayed two coats of clear auto gloss to 'fix' the ink, in accordance with the instructions).

I hope these wordy notes might encourage others to have a go at building this most useful little device. (A nice winter project!).

Special thanks to Guy, 'i4cy', for conceiving and designing the converter, and for programming and supplying the PIC.

Have fun!
Attached Thumbnails
Click image for larger version

Name:	Inside View MK2.jpg
Views:	273
Size:	67.9 KB
ID:	152796   Click image for larger version

Name:	Angled View.jpg
Views:	216
Size:	52.5 KB
ID:	152797   Click image for larger version

Name:	Front View MK2.jpg
Views:	220
Size:	52.5 KB
ID:	152798   Click image for larger version

Name:	Front panel sprayed white.jpg
Views:	191
Size:	14.4 KB
ID:	152799   Click image for larger version

Name:	AM FM Converter MK2 Front Panel.jpg
Views:	190
Size:	40.5 KB
ID:	152800  

__________________
David.
BVWS Member.
G-QRP Club member 1339.
David G4EBT is offline  
Old 24th Nov 2017, 3:23 pm   #58
David G4EBT
Dekatron
 
David G4EBT's Avatar
 
Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 5,690
Default Re: FM to AM Converter?

There was a slight error on the wording of the front panel label which has been brought to my attention. I've corrected that and have appended the corrected version. If anyone would like the full-sized artwork for label, or the artwork for the printed circuit board mask, (either negative or positive), I'll be happy to e-mail it to them if they drop me a PM.
Attached Thumbnails
Click image for larger version

Name:	AM FM Converter MK2 Front Panel.jpg
Views:	130
Size:	40.6 KB
ID:	152808  
__________________
David.
BVWS Member.
G-QRP Club member 1339.
David G4EBT is offline  
Old 24th Nov 2017, 4:37 pm   #59
Al (astral highway)
Dekatron
 
Al (astral highway)'s Avatar
 
Join Date: Nov 2006
Location: London, UK.
Posts: 3,496
Default Re: FM to AM Converter?

Hello David,

Thank you for such s detailed and illuminating post! What a great idea!
I’ll def add this to my list. I’d love to receive FM on my Pre-war Marconi.

The artwork is amazing, too. I’ll have to try that method ...

I hope lots of forum members try this one out!

Thanks again David
__________________
Al
Al (astral highway) is offline  
Old 24th Nov 2017, 4:51 pm   #60
Philips210
Nonode
 
Join Date: May 2007
Location: Redruth, Cornwall, UK.
Posts: 2,533
Default Re: FM to AM Converter?

Very nice work as usual David. Your projects always have that highly professional finish. Even the front panel slotted screws are set at a 45 degree angle.

I'm pleased with my FM to AM converter and must try to sort out a suitable enclosure for it.

Regards
Symon.
Philips210 is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 1:18 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.