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 > Success Stories

Notices

Success Stories If you have successfully repaired or restored a piece of equipment, why not write up what you did and post details here. Particularly if it was interesting, unusual or challenging. PLEASE DO NOT POST REQUESTS FOR HELP HERE!

Reply
 
Thread Tools
Old 2nd Nov 2021, 10:03 pm   #1
Steve G4WCS
Heptode
 
Steve G4WCS's Avatar
 
Join Date: Sep 2004
Location: Preston, Lancashire, UK.
Posts: 514
Default Lowe HF-150 cleanup and LCD backlight

I've stripped the receiver for cleaning the cabinet components. While I'm in it I decided to have a go at backlighting the LCD display. First attempt was a couple of LEDs in a perspex block to illuminate the LCD from the side. Not successful.

I've done a few LED conversions on car radios, dashboards etc and realised that it would need diffused lighting from behind to be successful. In order to do this, the foil from the rear of the LCD needs to be carefully removed. Now for decision on colour. The HF-150 Europa is backlit orange, so this was the colour decided on. With the display removed I realised that there was space for a small PCB with surface mount LEDs on it, so ordered some orange top LEDs.

In the meanwhile, I've been fitting some under cabinet “ neon striplight LED in the kitchen. Having cut the excess of a piece it became apparent that the innards are a flexi PCB with LEDs and limiting resistors, and a small piece of this would mean that I didn't need to make a PCB for the topLEDs.
But how to make it orange ?

I've been playing with various bits of card, orange plastic, and milk bottle plastic for the diffuser.

I've settled on orange card directly in front of the LEDs, which also dims them nicely, and have tried a piece of milk bottle behind the display. It looks the right colour and brightness but isn't diffuse enough, nearly there. I'm awaiting some 0.5mm white Plasticard which I have used before, and am sure it will do the trick.

I'll post some more pics up of the finished article.
Attached Thumbnails
Click image for larger version

Name:	2E28DD01-E638-4AB8-8CFE-1D0AEB3337DB.jpg
Views:	96
Size:	54.7 KB
ID:	244884   Click image for larger version

Name:	D55BD64A-E6F3-46F5-BD5B-08A120B12F50.jpg
Views:	85
Size:	37.6 KB
ID:	244885   Click image for larger version

Name:	086AC664-165C-4BFF-8451-FAEE5CFDAB27.jpg
Views:	91
Size:	51.4 KB
ID:	244886   Click image for larger version

Name:	EABB35F6-708D-4F9F-B3B6-52E78141FCCC.jpg
Views:	97
Size:	54.8 KB
ID:	244887   Click image for larger version

Name:	4ECD81AD-ED32-4C6A-BD9A-06858DCB2447.jpg
Views:	95
Size:	41.8 KB
ID:	244888  

Steve G4WCS is offline   Reply With Quote
Old 2nd Nov 2021, 10:05 pm   #2
Steve G4WCS
Heptode
 
Steve G4WCS's Avatar
 
Join Date: Sep 2004
Location: Preston, Lancashire, UK.
Posts: 514
Default Re: Lowe HF-150 cleanup and LCD backlight

More pics
Attached Thumbnails
Click image for larger version

Name:	3DB0E2CE-EED5-455A-839A-17E7FF3A1B19.jpg
Views:	90
Size:	50.0 KB
ID:	244889   Click image for larger version

Name:	DFBACEEB-FB46-451B-8C99-88437C50E4F9.jpg
Views:	96
Size:	59.0 KB
ID:	244890   Click image for larger version

Name:	A03348BD-F284-478D-9A58-7874E2EC435C.jpg
Views:	99
Size:	46.9 KB
ID:	244891   Click image for larger version

Name:	E08ECCF0-C5EA-4EBE-91CE-CC80A75C7546.jpg
Views:	89
Size:	64.7 KB
ID:	244892   Click image for larger version

Name:	031BD1A7-FA5F-4F0C-8F88-A0E04F93C6B1.jpg
Views:	80
Size:	76.8 KB
ID:	244893  

Steve G4WCS is offline   Reply With Quote
Old 2nd Nov 2021, 11:05 pm   #3
SiriusHardware
Dekatron
 
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 7,687
Default Re: Lowe HF-150 cleanup and LCD backlight

There was actually an official after-sales mod available from Lowe to do exactly what you are doing. The reason they weren't backlit by default is that they were primarily intended to be used portable (battery powered) and a constantly lit backlight would have shortened the battery life quite a bit.

Speaking of batteries - in case you didn't notice, the unit is intended to use rechargeable batteries which it will try to charge whenever you have external power connected and the radio is turned OFF at the power switch - it uses an ingenious arrangement which places two strings of batteries in parallel when charging so that the batteries can be charged from the same nominal 12V supply as the radio runs from when it is turned on.

Therefore, never fit non-rechargeable batteries or if you do, never plug in the external DC supply while they are fitted and the radio is switched off.

I've had one of these since they were originally on sale - oddly enough, it's not the lack of a backlight which irritates me about them, it's the lack of an S-Meter - difficult to forgive, on a communications receiver.
SiriusHardware is offline   Reply With Quote
Old 3rd Nov 2021, 9:14 am   #4
Steve G4WCS
Heptode
 
Steve G4WCS's Avatar
 
Join Date: Sep 2004
Location: Preston, Lancashire, UK.
Posts: 514
Default Re: Lowe HF-150 cleanup and LCD backlight

Interesting info, thanks. I hadnt read the manual yet and was unaware of the battery situation. I may try it with the batteries out of the FT-290. Yes an S-meter would be good, I don’t know whether there are any circuits out there for an external one, I do have a few led bargraph displays in my led tin that could make a funky little unit
Steve G4WCS is offline   Reply With Quote
Old 3rd Nov 2021, 7:31 pm   #5
Steve G4WCS
Heptode
 
Steve G4WCS's Avatar
 
Join Date: Sep 2004
Location: Preston, Lancashire, UK.
Posts: 514
Default Re: Lowe HF-150 cleanup and LCD backlight

Still not sure on the backlight. It may have to go. I've done the mod to get an agc voltage out of it for a external S meter, and given it an earth post. Just had a tune about on an inverted L . It's a super sounding set . Just caught Billy Connolly's national anthem on radio 4

https://youtube.com/shorts/w5iZtcQsNS0?feature=share
Attached Thumbnails
Click image for larger version

Name:	C13D575E-8C4D-4B44-B639-78FBF225DBBD.jpg
Views:	57
Size:	48.1 KB
ID:	244945   Click image for larger version

Name:	5F26ACA4-A65D-4EA7-8E2E-EF7F3FEDE8DB.jpg
Views:	44
Size:	66.3 KB
ID:	244946   Click image for larger version

Name:	104E3292-33EF-49F9-8A93-E2F34CBFD4CF.jpg
Views:	37
Size:	65.6 KB
ID:	244947   Click image for larger version

Name:	1AFBE858-6AC6-44C9-A1E9-9A5E466F0C95.jpg
Views:	37
Size:	59.2 KB
ID:	244949   Click image for larger version

Name:	45962D9C-9A53-4BB0-99FA-3DAD8DC21639.jpg
Views:	39
Size:	81.2 KB
ID:	244950  


Last edited by Steve G4WCS; 3rd Nov 2021 at 7:47 pm.
Steve G4WCS is offline   Reply With Quote
Old 3rd Nov 2021, 7:34 pm   #6
Steve G4WCS
Heptode
 
Steve G4WCS's Avatar
 
Join Date: Sep 2004
Location: Preston, Lancashire, UK.
Posts: 514
Default Re: Lowe HF-150 cleanup and LCD backlight

S meter circuit from the Sp150 manual
Attached Thumbnails
Click image for larger version

Name:	9A644042-2737-4BD4-A399-E23EE3BF876C.jpg
Views:	35
Size:	53.5 KB
ID:	244951   Click image for larger version

Name:	9AE27FF6-5240-4D40-B6E2-9E9EE577276B.jpg
Views:	36
Size:	71.5 KB
ID:	244952  
Steve G4WCS is offline   Reply With Quote
Old 3rd Nov 2021, 8:33 pm   #7
SiriusHardware
Dekatron
 
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 7,687
Default Re: Lowe HF-150 cleanup and LCD backlight

Thanks, but I confess I am slightly baffled, as that circuit appears to show the signal from the AUDIO IN jack going to the input of what I suppose must be an audio-level-to-voltage converter feeding the S-Meter.

I've never seen an SP150 but I can only assume that these would normally have REC OUT from the HF150 connected to AUDIO-IN on the SP-150, in which case surely that meter reading can only be audio-level derived?

At the same time you're talking about having modified the AGC circuit so that you can derive a meter output from that - that's more like the kind of thing I was expecting.

At work, we have amber LED backlight panels which are I would guess about 2cm by 4cm and maybe 1.5 - 2mm thick and they give out a uniform amber glow across the whole panel. (I can be more precise about dimensions tomorrow).

The units these are in tend to get dropped a lot and that takes out the display but not the backlight, so I can always rescue a working backlighter from a dud display.

I don't know how much space you have between the insides of the legs of the display? Also, how much of a gap is there between the rear face of the display and the main PCB when the display is fitted?
SiriusHardware is offline   Reply With Quote
Old 3rd Nov 2021, 8:37 pm   #8
SiriusHardware
Dekatron
 
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 7,687
Default Re: Lowe HF-150 cleanup and LCD backlight

Somewhere around, I have some PIC16F690 code and a circuit for an entry keypad for the HF150 - I've still got the actual homebrew unit built up, it works fine. It lets you go straight to a specific frequency by typing the digits in. The keypad may also support other functions through the use of # and *, I don't know because I have never seen the manual for the official HF-150 keypad.
SiriusHardware is offline   Reply With Quote
Old 3rd Nov 2021, 9:45 pm   #9
Steve G4WCS
Heptode
 
Steve G4WCS's Avatar
 
Join Date: Sep 2004
Location: Preston, Lancashire, UK.
Posts: 514
Default Re: Lowe HF-150 cleanup and LCD backlight

I think there has been some sort of disconnect, literally, between who did the agc output mod and whoever drew the circuit for the sp150. The output from the HF 150 is wired to the black post on the wire antenna input, which has had its track to case earth cut. Without the benefit of an SP150 to look at Im not sure where this voltage would be fed in. Ill have a look at the manual Ive downloaded tomorrow to see if it gives any clues. A couple
Of those backlight panels may do the trick, the leds Ive put in are casting a shadow across the main processor, I had thought about EL backlights which are available but was concerned about the inverter putting out RF hash. I think whichever way to go it needs to not involve removing and replacing the LCD display again, obviously its very delicate, the pins are very thin and pushed into turned pin sockets, Ive got away with not breaking it once and dont want to risk it again. For the S meter implementation I had googled the lm3915 led bargraph driver, but looking online, a complete kit with ic, leds, and pcb was available for less than the cost of the ic’s alone.
Steve G4WCS is offline   Reply With Quote
Old 3rd Nov 2021, 9:46 pm   #10
Steve G4WCS
Heptode
 
Steve G4WCS's Avatar
 
Join Date: Sep 2004
Location: Preston, Lancashire, UK.
Posts: 514
Default Re: Lowe HF-150 cleanup and LCD backlight

I do have an original keypad that came with the radio, havent tried it yet though
Steve G4WCS is offline   Reply With Quote
Old 4th Nov 2021, 4:12 pm   #11
Steve G4WCS
Heptode
 
Steve G4WCS's Avatar
 
Join Date: Sep 2004
Location: Preston, Lancashire, UK.
Posts: 514
Default Re: Lowe HF-150 cleanup and LCD backlight

Had another go with the backlighting. Much more pleasing to the eye.

Also spotted a pad for an “option” diode off pin 7 of q4 wonder what it does
Attached Thumbnails
Click image for larger version

Name:	4D8280B2-D22D-49DC-BB5F-E84B244B6456.jpg
Views:	44
Size:	53.6 KB
ID:	245002   Click image for larger version

Name:	786242C8-2D45-4617-A230-4E3718E93091.jpg
Views:	43
Size:	57.6 KB
ID:	245003   Click image for larger version

Name:	78B5E7E3-7BFF-46EC-89DA-C899E744099E.jpg
Views:	52
Size:	66.0 KB
ID:	245004   Click image for larger version

Name:	9407BDD6-E562-46A5-A37C-37A5C9E5050B.jpg
Views:	37
Size:	52.7 KB
ID:	245005   Click image for larger version

Name:	858559F5-E09D-48A8-AE9C-A85331226F1B.jpg
Views:	30
Size:	56.4 KB
ID:	245006  

Steve G4WCS is offline   Reply With Quote
Old 4th Nov 2021, 6:31 pm   #12
SiriusHardware
Dekatron
 
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 7,687
Default Re: Lowe HF-150 cleanup and LCD backlight

Maybe it enables TX? (Kidding).

Those LED backlights I mentioned are quite a bit bigger than the 2cm by 4cm I guessed at - had a hectic day at work today so I couldn't really pursue it further. It sounds as though you've got it working to your satisfaction now anyway?
SiriusHardware is offline   Reply With Quote
Old 5th Nov 2021, 7:48 am   #13
Steve G4WCS
Heptode
 
Steve G4WCS's Avatar
 
Join Date: Sep 2004
Location: Preston, Lancashire, UK.
Posts: 514
Default Re: Lowe HF-150 cleanup and LCD backlight

Morning. Tx enable would be good . Im wondering if its to do with different frequency steps. Yes im happy with the backlighting now thanks anyway. Going to put a scope on the agc output and see what the voltage range is
Steve G4WCS is offline   Reply With Quote
Reply

Thread Tools



All times are GMT. The time now is 6:41 am.


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 - 2022, vBulletin Solutions, Inc.
Copyright ©2002 - 2021, Paul Stenning.