Posts: 825
Threads: 113
Joined: Aug 2012
City: The Villages
State, Province, Country: Florida
Hi guys,
I just did a recap on this Hippo. I even replaced most of the mica caps as well as a good amount of out of range resistors. The tubes have been tested and I replaced 2 of them. Performed an alignment.
Reception is great but between stations there is a VERY noticeable squeal. Any ideas where to look?
http://www.nostalgiaair.org/Resources/634/M0013634.htm
Thanks
Eric
The Villages, FL
Member: Philco Phorum, ARF, ARCI & Radiomuseum.org
Posts: 671
Threads: 147
Joined: Jun 2011
City: Elko,MN.
I have run into this before, and have been able to get rid of it by fine tuning the alignment.
murf
Posts: 13,776
Threads: 580
Joined: Sep 2005
City: Ferdinand
State, Province, Country: Indiana
Is your loop antenna properly connected? If one wire is disconnected, the set will squeal, howl, buzz, and in general not play correctly.
--
Ron Ramirez
Ferdinand IN
Posts: 1,703
Threads: 55
Joined: Sep 2005
City: Evanston, IL
If your loop is connected you may also try a slight stagger-tune of the I.F.'s as suggested above.
Chuck
Posts: 825
Threads: 113
Joined: Aug 2012
City: The Villages
State, Province, Country: Florida
It came with no antenna. The loop is connected but it is from what I think was a 46-250. Would that make the difference? If so what can be done to correct this?
Eric
The Villages, FL
Member: Philco Phorum, ARF, ARCI & Radiomuseum.org
Posts: 16,476
Threads: 573
Joined: Oct 2011
City: Jackson
State, Province, Country: NJ
If it squeals on you tell it it is not an honorable thing to do.
And make sure it is loop and not a noose 
Now on teh seriuous note, I only have the sch for 48-620, but if it is also an AC/DC set, there is a capacitor or a capacitor in series with small inductance conencting the electrical common and RF common (chassis). If this cap or inductor are bad the radio will misbehave including squealing, howling, roaring, motorboating and occasionally uttering some bad words on its own at which point you should turn it off, pull the belt from your pants, give it a good threshing and then inspect for bad parts and re-align.
Posts: 825
Threads: 113
Joined: Aug 2012
City: The Villages
State, Province, Country: Florida
OK Morzh, here is the schematic for the 48-460
48-460
Would it be C5?
Eric
The Villages, FL
Member: Philco Phorum, ARF, ARCI & Radiomuseum.org
Posts: 825
Threads: 113
Joined: Aug 2012
City: The Villages
State, Province, Country: Florida
Something else that I just discovered: With the antenna disconnected I get a soft high pitched squeal that changes with volume but doesn't change with movement of the tuning cap.
Eric
The Villages, FL
Member: Philco Phorum, ARF, ARCI & Radiomuseum.org
Posts: 16,476
Threads: 573
Joined: Oct 2011
City: Jackson
State, Province, Country: NJ
No. C19.
But C5 is also worth checking as without it the antenna will simply not work.
Posts: 825
Threads: 113
Joined: Aug 2012
City: The Villages
State, Province, Country: Florida
C5 is new. Any idea why there is a soft squeal with no antenna connected?
Eric
The Villages, FL
Member: Philco Phorum, ARF, ARCI & Radiomuseum.org
Posts: 16,476
Threads: 573
Joined: Oct 2011
City: Jackson
State, Province, Country: NJ
Is C19 new or is it even there?
Posts: 825
Threads: 113
Joined: Aug 2012
City: The Villages
State, Province, Country: Florida
Yes it is there. I have 2 schematics. This one shows a .2mf and the other shows a .5mf. I used a .5 because that is what was in there. It didn't have the wire wrapped around it. I don't think that is needed anymore. Is it?
Eric
The Villages, FL
Member: Philco Phorum, ARF, ARCI & Radiomuseum.org
Posts: 16,476
Threads: 573
Joined: Oct 2011
City: Jackson
State, Province, Country: NJ
Did it have a wire wrapped around it before?
0.2uF or 0.5uF does not matter, it is an RF link cap between the two commons, either will work fine.
Posts: 825
Threads: 113
Joined: Aug 2012
City: The Villages
State, Province, Country: Florida
No wire, so I tried one. No change.
Eric
The Villages, FL
Member: Philco Phorum, ARF, ARCI & Radiomuseum.org
Posts: 761
Threads: 56
Joined: Jul 2013
City: Kentucky
Hippos usually have rubber wiring. Did you replace any wires, or cover them with heat shrink? If so, check the routing of the wires. Sometimes solving a squeal is as simple as moving a wire 1/4 inch. If this isn't the trouble, i think your alignment might be a little too "hot". Like Chuck said, un-align it a little and see if the squeal stops.
The artist formerly known as Puhpow! 8)
Users browsing this thread: 1 Guest(s)
|
|
Recent Posts
|
|
Need to purchase some accessories for restoration of my Old Philco Radio
|
| Here is a list of resources found in our online library that you might find useful. Mike's Gobs of Knobs email addres...klondike98 — 01:46 PM |
|
First Radio restoration
|
| Hi Tubeman,
Welcome to the Philco Phorum. Phamily Phriendly Pfun with Phine Pholks Phull of Philco Phacts. (See a p...MrFixr55 — 12:33 PM |
|
First Radio restoration
|
| You could post in the WANTED ADs section here on the Phorum and see if anyone has an RF generator that they want to sell...klondike98 — 11:55 AM |
|
Zenith H725
|
| Good ideas, thank you Arrange and Rich. I have the adhesive aluminum foil already and can try that immediately.
More ...EdHolland — 10:18 AM |
|
Graphics for majestic 1050 dial glass.
|
| Murf;
I found this thread on the ARF, the first photo has a pretty good view of the dial glass.
Regards
ArranArran — 01:12 AM |
|
Zenith H725
|
| hello Ed,
how about that speacial tape used for ducting it's like foil or how about thin piece of
aluminum roof flash...radiorich — 12:19 AM |
|
Zenith H725
|
| Ed;
One material that I have seen, but never tried for this was material for making exhaust gaskets, it's similar to ...Arran — 11:42 PM |
|
Zenith H725
|
| I just remembered, I have some hi temp silicone rubber material which could do the trick. Or a piece of FR4 laminate. Th...EdHolland — 08:39 PM |
|
Zenith H725
|
| The PSU filter cap arrived today (thank you USPS!) so I will work on that later.
Meanwhile, I have the dial, speaker...EdHolland — 06:42 PM |
|
Philco 610B oscillator wiring
|
| Thanks Terry. After checking my notes I think I recorded about -10v at the 6A7 G4/control grid. The screen grid (G3 &...Tubester — 05:59 PM |
|
Who's Online
|
| There are currently no members online. |
|
 
|
![[-]](https://philcoradio.com/phorum/images/bootbb/collapse.png "[-]")
