|
Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
|
Thread Tools |
8th Feb 2020, 4:17 pm | #1 |
Hexode
Join Date: Mar 2008
Location: Melbourne, Victoria, Australia
Posts: 289
|
Grundig 3060 75% perfect, help !!
Hi All,
I have created many threads in restoring a dead 3060. After replacing the ECC81, EBf89, ECH81, the radio is just booming on AM. (SW is fanstasic with just a wire). Waiting for an EL84.. I adjusted V and IV, which are the top and bottom coils which are towards the rear cover. The adjustment of the top coil, increased the sensitivity of SW by 1000% and i am very happy..all AM bands now.. just a short wire and i can pick all of europe, and i am in melbourne. PROBLEM: FM used to work, but was low in volume. I seem to have killed it at some point, and now its dead !! I need some help to understand if the capacitor i melted could be the cause. I think the melted capacitor is either C36 (10pf) or C41(100pf) as coil e, d is at the dial end (adjusting the rear most coil affected only AM) Can someone PLEASE tell me what "dial side" coils "e", "d", do ? i think they are FM ? and cause i melted the rear cap, its no longer working. |
8th Feb 2020, 8:30 pm | #2 |
Dekatron
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,428
|
Re: Grundig 3060 75% perfect, help !!
Appears to be the 10.7Mhz IF transformer for the FM band. If either of those two capacitors are faulty it will affect FM performance, if S/C it will stop any reception on the FM band. Should that set of coils have a screening can, the one on RM does. The caps e and d tune the IF transformer coils.
__________________
Frank |
9th Feb 2020, 2:58 pm | #3 |
Hexode
Join Date: Mar 2008
Location: Melbourne, Victoria, Australia
Posts: 289
|
Re: Grundig 3060 75% perfect, help !!
Frank, can i use Ceramic 100pF 50V caps for these ? i cant find higher voltage ratings easily... Tks
|
9th Feb 2020, 4:52 pm | #4 |
Dekatron
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,428
|
Re: Grundig 3060 75% perfect, help !!
Mouser Australia have CDE mica capacitors which would probable be better but you could use the ones you have as a test.
https://au.mouser.com/Passive-Compon...itors/_/N-5g97
__________________
Frank |
10th Feb 2020, 2:28 pm | #5 |
Hexode
Join Date: Mar 2008
Location: Melbourne, Victoria, Australia
Posts: 289
|
Re: Grundig 3060 75% perfect, help !!
Finally fixed the FM... Given it was DEAD with no noise on FM, i checked the voltges around the ECC85, with the FM mixer/amp. Voltages were good, but still no FM.
I poked around with the CRO and found no signal at the FM IF transformer, F1 7206-208 and while poking around, found a dry joint at the wire that goes from the Transformer to the grid of the ECH81. Always good to poke around in the signal path, once voltages are verified to be good.. So AM, SW is just boomin, after tuning transfomer F2 coils V and IV. I can listen to so many shortwave stations, with just a short wire connected.. just love the AM and Shortwave sensitivity and tone.. its magic !! I think the highest frequency tone control, actually opens up the IF bandwidth, so you can get incredible clear AM !! Unfortunately i played around with coil F5, which is the FM discriminator i think. Tweaking it caused the audio to become very lound and distored, so just kept playing unti the audio was clear.. not ideal for i dont listen to much FM, and this radio stops at 100Mhz. Last task is the Anetnna position indicator, i broke it while removing it and it needs some interesting mechaincal engineering.. |
10th Feb 2020, 2:37 pm | #6 |
Dekatron
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,428
|
Re: Grundig 3060 75% perfect, help !!
Thanks for the update.
__________________
Frank |