Boosting Signal on my old school Sanyo DXing radio.

[Jacob leonard]

I just got an Sanyo DXing radio and besides lack of info I got a Sanyo M777OK. I figured I can start small before I shell out a paychecks worth on a Grundig 750 or some other overtly powerful receiver. But I love my Sanyo, its loud as heck and its very versatile but here is what I want to do. I however can't do anything like hard mounting antennas up since I live on a campus, bottom floor of a brick building with wide windows. I want to boost the input on the radio itself. I adjust that bugger as perfect as I can get it but all I pull in is KCCR (Community College Radio) country and Top 40s. I can get faintly NOAA and NPR some right wing radio and sometimes Classic rock but just faintly.

Also where can I find an owners manual as well?

 

[BJ radionut]

http://www.electronic-circuitry.com/e/action/ShowInfo.php?classid=72&id=227328

Might be of help
GL
All the Best
Gary

 

[Beetle]

About 30 seconds on Google:
http://www.hifi-manuals.com/Sanyo/M-7770-K/downloads

 

[Soup-man]

I just got an Sanyo DXing radio and besides lack of info I got a Sanyo M777OK. I figured I can start small before I shell out a paychecks worth on a Grundig 750 or some other overtly powerful receiver. But I love my Sanyo, its loud as heck and its very versatile but here is what I want to do. I however can't do anything like hard mounting antennas up since I live on a campus, bottom floor of a brick building with wide windows. I want to boost the input on the radio itself. I adjust that bugger as perfect as I can get it but all I pull in is KCCR (Community College Radio) country and Top 40s. I can get faintly NOAA and NPR some right wing radio and sometimes Classic rock but just faintly.

Also where can I find an owners manual as well?

I'm not really sure what you are asking here.
DX means out of country - the stations you are able to receive doesn't sound to me as being out of country.
The premium radio you are talking about would be laughable at best to anyone that owns even a less expensive amateur radio - Icom, Yaesu, Kenwood all mode, all band transceiver.
In radio, it is the antenna that does most of the work. The receivers job is to receive what the antenna gives it and hopefully if it has some filtering, can remove the noise, and then all you have left is the intelligence.
Amplification does not solve anything. When you amplify crap, all you get is louder crap. If you are in college and you want to play radio, ask the college to move you to a dorm room on the top floor of the building and then open a window and drop a long wire antenna out the window at night, or wrap the long wire antenna, dipole, what ever, around the building.
Longer wavelengths may penetrate the concrete and steel reinforced building, but having a large antenna, outside is what you will need to have good reception.
Always spend your money on the antenna first. Then when you discover that the receiver is at fault, you can invest in better receivers. Hamfests are an excellent place to find used receivers. Many older receivers are still some of the better receivers out there. The Collins R390 is stillone of the better ones out there in my opinion..
Drake C line, Hammarlund HQ's and National - NC's are good investments..

 

[vkrules]

Sorry mate, 3 words for you antenna , antenna ,antenna

 

[Captain Kilowatt]

Sorry mate, 3 words for you antenna , antenna ,antenna

I have three more words that may be even more important. "Getta betta radio". That Sanyo is not a good choice for what you want really.It's just a cheap (no offense) AM/FM/cassette deck. A fantastic AM/FM receiver is the General Electric GE Super radio especially the Super radio 1 or 2. The Super Radio 3 is OK but sometimes the frequency jumps due to a dirty tuning control. It is varactor tuned by a DC voltage rather than by a tuning capacitor.They have incredible sound quality, wide and narrow bandwidth for AM reception. Wide for local strong signal for best audio sound and narrow for DXing. It also has external antenna terminals making it super easy to connect a wire antenna. I have used the GE Super Radio 2 before and own a Super Radio 3 and hands down it is the best basic AM/FM radio I have ever owned.

 

[loosecannon]

Jacob Leonard,

While all the suggestions posted so far are legit, and from knowledgeable people; my guess is that in your current situation, it's either make this radio work for you, or move on to some other pastime.

so, here's what you need to know- what you are experiencing is called "front end overload" which means that the signals coming into your radio from the big powerful AM sports stations and other big commercial radio stations are just too darn strong for your little radio, and so instead of just amplifying that weak signal on 9 mhz, it also amplifies KCCR and any other signal strong enough to overload the receiver.

My guess is that no matter where you tune, these same stations keep finding their way into your receiver. Google front end overload to learn more about it.

the easy fix is to buy a receiver with a more robust and selective front end, but that is most likely not in the cards for you right now.
the cheapest fix is to make what is known as a "broadcast band filter" which basically attenuates any signal from 530-1600KHZ (AM broadcast band) but will allow signals above and below that range.

this is a pretty simple circuit to build and involves buying a couple of ferrite beads, some magnet wire, a couple of capacitors and a small metal box.

here is a link to a schematic of how to build one: http://www.seekic.com/circuit_diagram/555_Circuit/AM_BCB_500_~_2000kHz_band_pass_filter_circuit.html

you should be able to buy the caps and even the inductors if you don't want to wind your own.


the next thing you need is a good antenna that doesn't need to be outside or high up in the air. for this i recommend the "broomstick antenna".
basically its a wooden dowel like a broom handle with wire wrapped all the way up the handle, with a metal disc (pizza pan) on the top.
here is a link to an article on how to build one: http://www.hard-core-dx.com/nordicdx/antenna/special/bromstik.html

here's the deal though!
if you just make the antenna and don't use the filter, then you will only bring in more AM commercial stations that will saturate your receivers input and you will be worse off than you are right now.

you have to do both in order to turn that Sanyo into a working shortwave receiver.

best of luck and feel free to ask questions about this here. there are a lot of smart guys here on the forum.
LC

 

[Captain Kilowatt]

so, here's what you need to know- what you are experiencing is called "front end overload" which means that the signals coming into your radio from the big powerful AM sports stations and other big commercial radio stations are just too darn strong for your little radio, and so instead of just amplifying that weak signal on 9 mhz, it also amplifies KCCR and any other signal strong enough to overload the receiver.

9 MHz?? I thought his radio was an AM/FM/cassette style not shortwave. Jacob could you please clarify what it is you have. My search for a Sanyo M7770K shows an AM/FM cassette boombox. How about a picture of it?

http://www.shizaudio.ru/audio/details.php?image_id=3536
http://www.shizaudio.ru/audio/details.php?image_id=3536
http://www.shizaudio.ru/audio/details.php?image_id=3536

 

[Captain Kilowatt]

Never mind. I just blew up an image of one using Irfanview and see it covers a SW band as well. AFAIAC it is still not a SW receiver. Performance will be abysmal.

 

[loosecannon]

just noticed that CK.

I saw "DXing" and assumed he meant that he had a shortwave receiver that was experiencing front end overload, but i guess he could just want to receive AM and FM broadcasts better.

i guess we'll find out if he responds.
LC

 

[Beetle]

Brick buildings are pretty good RF sponges. I wouldn't bet that an indoor antenna, unless it's right up against the window, is going to be much good.

 

[Captain Kilowatt]

Brick buildings are pretty good RF sponges. I wouldn't bet that an indoor antenna, unless it's right up against the window, is going to be much good.

I'm wondering how he will connect any type of external antenna since the telescopic whip is for FM and maybe SW but it uses an internal ferrite bar for AM reception. He could try clipping a wire to the whip to see if it increases SW reception. To increase AM reception it may help if several turns of the antenna wire are wrapped around the entire radio or perhaps several turns a few inches in diameter and then moved around the case to find the best spot for reception. This causes the signal to be induced into the ferrite bar similar to a transformer.

 

[Soup-man]

My brother recently returned from Saudi Arabia. There was no commercial AM / FM radio stations of interest there, but he was able to buy locally a SONY Boombox style receiver that included Short Wave Frequencies. The downfall was that they did not use 120 vac over there, and that he had to purchase some type of power cord and cut the cord plug off when he got home. I guess it was wired for different voltages 120 / 240 etc, and by moving the wires in the plug, could be used either or.
This particular receiver had accommodations on the back of the cabinet for an external antenna. My only gripe was that the power cord was only 3 feet long, not long enough to get the radio close enough to a window in his house to try it out to see how good it performed while I was there.
Had he asked, I probably would have sold him my Kenwood TS 590s and used the proceeds to purchase a newer model Kenwood 590SG.
The US Navy once claimed that all you need for decent reception was a wire 6 - 10 feet long for shortwave reception. Their claim was that either the signal was present, or it was not. They claimed that making the antenna longer, would increased the noise, along with the signal. http://tailspintopics.blogspot.com/2014/01/world-war-ii-navy-carrier-airplane.html

 

[Captain Kilowatt]

The US Navy once claimed that all you need for decent reception was a wire 6 - 10 feet long for shortwave reception. Their claim was that either the signal was present, or it was not. They claimed that making the antenna longer, would increased the noise, along with the signal. http://tailspintopics.blogspot.com/2014/01/world-war-ii-navy-carrier-airplane.html

Yeah tell that to those of us that like listening to AM broadcast or longwave. 6-10 feet pf wire is pretty much a dummy load down there. Even on shortwave there are great benefits to a long wire. I used to have a 600 foot long wire antenna and it was FANTASTIC but I did live in a rural RFI quiet area.

 

[2RT307]

I just got an Sanyo DXing radio and besides lack of info I got a Sanyo M777OK. I figured I can start small before I shell out a paychecks worth on a Grundig 750 or some other overtly powerful receiver. But I love my Sanyo, its loud as heck and its very versatile but here is what I want to do. I however can't do anything like hard mounting antennas up since I live on a campus, bottom floor of a brick building with wide windows. I want to boost the input on the radio itself. I adjust that bugger as perfect as I can get it but all I pull in is KCCR (Community College Radio) country and Top 40s. I can get faintly NOAA and NPR some right wing radio and sometimes Classic rock but just faintly.

Also where can I find an owners manual as well?

Have you thought about trying an SDR? I'm running the SDRplay RSP-1, and it's a lot of fun.

http://www.hamradio.com/detail.cfm?pid=H0-014408

Of course you have to use a laptop or tablet with it, but most folks already have one laying around. A cheaper unit is the Soft66, which will do HF, VHF, UHF as well. Software is free (SDR-Console, SDRuno, HDSDR, SDR#, etc.).

73,
Brett