Questions about radio's and antenna's

Mike Bates · **Posted:** Sun Mar 16, 2008 12:55 pm

Maybe some can answer a question. I was looking over some P-38 pictures and noticed some of them had antenna wires going to the radio's and some didn't. I added some pictures to show what I'm talking about.
Was there only certain kinds of radio's that required antenna's ?

With antenna

without antenna

Mike

Matt Gunsch · **Posted:** Sun Mar 16, 2008 1:17 pm

All radios require antennas, just different types. The types and locations varry by installed gear.

Misterg97 · **Posted:** Sun Mar 16, 2008 1:59 pm

Concurr on all aircraft had antennas .... The second picture clearly shows the patch of the 94th Fighter Squadron .... a coincidence as we recently received an inquiry as to our ability to embroiderthat design.

Thanks for the photos.

Mike Bates · **Posted:** Sun Mar 16, 2008 3:06 pm

Ok, has anyone seen any other antenna set ups on P-38's beside from the top of the tails to the back of the canopy? Will have to go start looking at pictures again and see if I can figure this out.

Thanks,
Mike

51fixer · **Posted:** Sun Mar 16, 2008 6:25 pm

Mike Bates wrote:

Ok, has anyone seen any other antenna set ups on P-38's beside from the top of the tails to the back of the canopy? Will have to go start looking at pictures again and see if I can figure this out.

Thanks,
Mike

You have different types of radios and their uses. Communication, navigation and transponder (IFF). Aircraft size also dictated how much equipment could be fitted. That is why bombers had a radio operator on the crew but a fighter pilot had to do it on their own. As technology evolved changes came about. Also different geographic regions presented different needs. VLR nav in the pacific late in the war comes to mind. Radio systems were often changed in overseas depots on new and older aircraft as well.
In short, each photo might be different depending on the above info.
Others here might know more about the individual models of radios.
Rich

Matt Gunsch · **Posted:** Sun Mar 16, 2008 6:56 pm

You can see the difference in radio gear in your pictures. Behind the pilot in each picture you can see a different type of radio, also your pictures appear to be of different models of P-38s.

51fixer · **Posted:** Sun Mar 16, 2008 7:12 pm

Matt Gunsch wrote:

You can see the difference in radio gear in your pictures. Behind the pilot in each picture you can see a different type of radio, also your pictures appear to be of different models of P-38s.

Top pic is later P-38 w/flat protective windscreen.
Lower has curved windscreen with protective flat portion inside windscreen.
Rich

Taigh Ramey · **Posted:** Sun Mar 16, 2008 7:56 pm

Both pictures have the same radio set, namely the SCR-522, VHF command radio installed behind the pilot. The difference is one is mounted transverse and one fore and aft. The SCR-522 used a blade antenna (AN-104) often called an axe handle.

The wire antenna on fighters was often used for the other type of command set (SCR-274N) or a small navigation radio manufactured by Setchel Carlson and other manufacturers.

It is possible that this P-38 could have had both command sets (SCR-274N and SCR-522) installed but I think it more likely that the antenna wire was used for the navigation radio mentioned above.

The wire antenna is also seen on Mustangs coming through the canopy and going to the vertical stabilizer.

The P-38 would likely have had an IFF, identification friend or foe, radio that would identify it to interrogating radar sets as friendly as long as it transmitted the code of the day or mission. The IFF antennas were usually a wire rod type of antenna about 10 or so inches long. These thin wire antennas are hard to spot on most photos unless the shot was taken fairly close. The IFF set, or SCR-695, was usually in the right boom of the P-38 so the antenna was typically mounted close to the radio.

The AN-104 is easy to spot as it does look like an axe handle and tapers toward the end. Some aircraft, the P-61 for example, had two SCR-522's and thus two AN-104 antennas.

Here is a shot from the P-38 association's web site that shows the AN-104 VHF antenna mounted just in front of the nose gear:

Here is another shot from the P-38 associations web site showing the IFF antenna on the bottom of the right boom and the AN-104 on the bottom of the nose.

You can also see the wire antenna, or at least the insulator and tension spring, from the canopy to the vertical stabilizer on both aircraft.

Mike Bates · **Posted:** Sun Mar 16, 2008 8:44 pm

Man that is just the kind of info I was looking for! Here's another photo, whats the smaller black box he has his left hand on?

Thanks,
Mike

Taigh Ramey · **Posted:** Sun Mar 16, 2008 9:00 pm

Hey Mike,

Cool shot.

He is tuning the set which they would do routinely for maintenance or when changing crystals for different frequencies.

He has the antenna disconnected (90 degree connector lying at the base of the radio) and has a dummy load hooked up for tuning. He also is looking at the meter in his hand to tune to a peak or dip as necessary to achieve the best output of the radio.

His hand is resting on the PE-94 power unit for the radio set. The power unit takes in 24-28 volts DC and has a rotary inverter to convert it to the high voltage needed for the transmitter. Those two units are the main components for the SCR-522 VHF transceiver set. The other components are the control head which was mounted on the right side of the P-38 cockpit, jack boxes and other small items depending on the installation.

Wheels up · **Posted:** Sun Mar 16, 2008 10:16 pm

Quote:

rotary inverter to convert it to the high voltage

So would this be what was regularily called a Dynamotor in prewar civilian applications?

sdennison · **Posted:** Sun Mar 16, 2008 10:53 pm

Taigh Ramey wrote:

Both pictures have the same radio set, namely the SCR-522, VHF command radio installed behind the pilot. The difference is one is mounted transverse and one fore and aft. The SCR-522 used a blade antenna (AN-104) often called an axe handle.

The wire antenna on fighters was often used for the other type of command set (SCR-274N) or a small navigation radio manufactured by Setchel Carlson and other manufacturers.

It is possible that this P-38 could have had both command sets (SCR-274N and SCR-522) installed but I think it more likely that the antenna wire was used for the navigation radio mentioned above.

The wire antenna is also seen on Mustangs coming through the canopy and going to the vertical stabilizer.

The P-38 would likely have had an IFF, identification friend or foe, radio that would identify it to interrogating radar sets as friendly as long as it transmitted the code of the day or mission. The IFF antennas were usually a wire rod type of antenna about 10 or so inches long. These thin wire antennas are hard to spot on most photos unless the shot was taken fairly close. The IFF set, or SCR-695, was usually in the right boom of the P-38 so the antenna was typically mounted close to the radio.

The AN-104 is easy to spot as it does look like an axe handle and tapers toward the end. Some aircraft, the P-61 for example, had two SCR-522's and thus two AN-104 antennas.

Here is a shot from the P-38 association's web site that shows the AN-104 VHF antenna mounted just in front of the nose gear:

Here is another shot from the P-38 associations web site showing the IFF antenna on the bottom of the right boom and the AN-104 on the bottom of the nose.

You can also see the wire antenna, or at least the insulator and tension spring, from the canopy to the vertical stabilizer on both aircraft.

Ok, so the reason the starboard engin is feathered is... :shock:

I checked the photos of my Dad's Lightning but cannot make out any antenna wires.

Matt Gunsch · **Posted:** Sun Mar 16, 2008 11:33 pm

Ok, so the reason the starboard engin is feathered is... :shock:

I checked the photos of my Dad's Lightning but cannot make out any antenna wires.[/quote]

Real simple answer, there is a couple hours more on the Starboard engine than the Port engine, he is just getting the times equal on both engines

Wheels up · **Posted:** Mon Mar 17, 2008 7:34 am

Quote:

Real simple answer, there is a couple hours more on the Starboard engine than the Port engine, he is just getting the times equal on both engines

Well, actually the starboard engine took a powder on the last mission when the jock overboosted it and it is far easier to fly it back to another base and let THEM exchange it, than deal with the flak from your own chief! :lol:

K5DH · **Posted:** Mon Mar 17, 2008 8:02 am

While we're on the subject of radio antennas, I have a question for the B-17 experts.

I'm under the impression that the fixed-length wire antenna for the liason radio ran from the insulator on the left side of the fuselage out to a point on the left wing, rather than up to the vertical tail. Is that correct? If so, where did the far end of the antenna attach to the wing? Does anyone have a photograph which shows this? How about a detail photo of the attach point and hardware? If that's not where the antenna was attached, then where was it attached? Photos? Details?

Thanks in advance for your help!

Dean the grateful

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