Forums :: Resources :: Features :: Photo Gallery :: Vintage Radio Shows :: Archives
Support This Site: Contributors :: Advertise


It is currently Oct Sun 20, 2019 12:54 pm


All times are UTC [ DST ]





Post New Topic Post Reply  [ 4 posts ] 
Author Message
 Post subject: Philips (Magnavox) D2999 - alignment experience/advice?
PostPosted: Mar Thu 22, 2018 3:04 pm 
New Member

Joined: Mar Thu 22, 2018 2:21 pm
Posts: 2
Hi,

I've just taken delivery of a Philips D2999 (vintage 1985-1989) via eBay. The unit I've purchased is in remarkably good physical condition. Putting it through its paces however has revealed that FM reception is off by about 100KHz (max signal strength and greatest signal clarity are about 100Khz away from one another) and on HF it's a wee bit off frequency as against the display (1Khz as a guesstimate, I've not tried to measure it more carefully yet). This is hardly surprising given the radio is circa 30 years old. I've got my hands on the service manual (available online via multiple sources) and wish to do an alignment job on it over the next few weeks. The Service manual has alignment instructions.

I'm not a professional RF/electronics engineer but over the years I've built up a fairly respectable ability with electronics and work with RF circuitry quite regularly. That said, this will be the first commercial off-the-shelf HF/FM receiver alignment I've done. I'm keen to have a go however. Before I get stuck in, is there (a) anyone who's actually done an alignment on this specific radio (or its sibling the D2935; the receiver electronics are the same I understand) and has experiences/advice to offer and/or (b) anyone who might have advice to offer on receiver alignment in general e.g. dos, don'ts, gotchas etc.

I've access to a well equipped RF workshop so (likely) have the tools/equipment required.

Thanks.

_________________
Cormac, EI4HQ
[Cork Harbour / UTC] NNNN++++


Top
 Profile  
 
 Post subject: Re: Philips (Magnavox) D2999 - alignment experience/advice?
PostPosted: Mar Fri 23, 2018 9:59 pm 
Member

Joined: May Sat 12, 2012 1:33 pm
Posts: 1697
Location: Rochester, NY.
I have not specifically worked on this particular receiver, but take the service manual procedures in order.
Check for any electrolytic caps that may need replacement.
Cycle and clean switch contacts as necessary, especially if the radio sat unused for awhile.
Input power supply voltages must be as stated. Check test point voltages to assess if any sections may need a closer look.
Table V shows the expected tuning voltages at various displayed frequencies. This may uncover why it seems off-frequency.
RF/IF osc tuning comes last.


Top
 Profile  
 
 Post subject: Re: Philips (Magnavox) D2999 - alignment experience/advice?
PostPosted: Mar Wed 28, 2018 6:09 pm 
New Member

Joined: Mar Thu 22, 2018 2:21 pm
Posts: 2
All noted with many thanks. Will post how I get on at a later date...

_________________
Cormac, EI4HQ
[Cork Harbour / UTC] NNNN++++


Top
 Profile  
 
 Post subject: Re: Philips (Magnavox) D2999 - alignment experience/advice?
PostPosted: Mar Thu 29, 2018 8:35 pm 
Member
User avatar

Joined: Jan Tue 31, 2012 1:55 am
Posts: 9851
Location: Mountains of Mourne. Ireland.
"Ed" Ei9GQ will fix 'er up for you Cormac, if you run into trouble!.Lol

73 de Greg... :)


Top
 Profile  
 
Post New Topic Post Reply  [ 4 posts ]  Moderator: Dave Doughty

All times are UTC [ DST ]


Who is online

Users browsing this forum: No registered users and 5 guests



Search for:
Jump to:  




























Privacy Policy :: Powered by phpBB